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To demonstrate image-guided preplan workflows for high-dose-rate (HDR) brachytherapy for advanced gynecological malignancies. Two different preplanning scenarios are presented: (1) CT- or MRI-based preplan with partial applicator in place; (2) Preplans generated from prior fractions. The first scenario can be applied to Syed-Neblett template-based implants or hybrid brachytherapy applicators, while the second scenario applies to hybrid applicators. Both scenarios use MRI or CT images acquired with the applicator in place to demonstrate tumor and applicator relative locations and therefore, provide the ability to show optimized suggested needle positions including the implant depths before the actual insertion. The preplanning techniques have demonstrated feasibility and shown five areas of potential improvement: (1) shorter procedure time, (2) decreased number of total needles inserted, (3) shorter physician tumor contour time, (4) shorter planning time, and (5) evaluation of appropriateness for brachytherapy. The use of image-guided brachytherapy preplanning improves clinical efficiency and is recommended for consideration for adaptation into clinical workflows for HDR interstitial and hybrid brachytherapy. [ABSTRACT FROM AUTHOR]

To demonstrate novel clinical implementation of a 3D transvaginal ultrasound (3DTVUS) system for intraoperative needle insertion guidance in perineal template interstitial gynecologic high-dose-rate brachytherapy and assess its impact on implant quality. Interstitial implants began with preimplant 3DTVUS to visualize the tumor and anatomy, with intermittent 3DTVUS to assess the implant and guide needle adjustment. Analysis includes visualization of the implant relative to anatomy, identification of cases where 3DTVUS is beneficial, dosimetry, and a survey distributed to 3DTVUS clinicians. Seven patients treated between November 2021 and October 2022 were included in this study. Twenty needles were inserted under 3DTVUS guidance. The tumor and vaginal wall were well-differentiated in four and all seven patients, respectively. Patients with tumours below the superior aspect of the vagina are suited for 3DTVUS. Four radiation oncologists responded to the survey. There was general agreement that 3DTVUS improves implant and anatomy visualization and is preferred over standard 2D ultrasound guidance techniques. Based on qualitative feedback from primary users and a small preliminary patient cohort, 3DTVUS imaging improves tumor and vaginal wall visualization during gynecologic perineal template interstitial needle implant and is a powerful tool for implant assessment in an intraoperative setting. [ABSTRACT FROM AUTHOR]

Evaluation of the management by first brachytherapy followed by radical hysterectomy (Wertheim type) compared to radical hysterectomy alone (Wertheim type) for the treatment of IB2 cervical cancer. Data from women with histologically proven FIGO stage IB2 cervical cancer treated between April 1996 and December 2016 were retrospectively abstracted from twelve French institutions with prospectively maintained databases. Of the 211 patients with FIGO stage IB2 cervical cancer without lymph node involvement included, 136 had surgical treatment only and 75 had pelvic lymph node staging and brachytherapy followed by surgery. The surgery-only group had significantly more adjuvant treatment (29 vs. 3; p = 0.0002). A complete response was identified in 61 patients (81%) in the brachytherapy group. Postoperative complications were comparable (63,2% vs. 72%, p = 0,19) and consisted mainly of urinary (36 vs. 27) and digestive (31 vs 22) complications and lymphoceles (4 vs. 1). Brachytherapy had no benefit in terms of progression-free survival (p = 0.14) or overall survival (p = 0.59). However, for tumors of between 20 and 30 mm, preoperative brachytherapy improved recurrence-free survival (p = 0.0095) but not overall survival (p = 0.41). This difference was not observed for larger tumors in terms of either recurrence-free survival (p = 0.55) or overall survival (p = 0.95). Our study found that preoperative brachytherapy had no benefit for stage IB2 cervical cancers in terms of recurrence-free survival or overall survival. For tumor sizes between 2 and 3 cm, brachytherapy improves progression-free survival mainly by reducing pelvic recurrences without improving overall survival. [ABSTRACT FROM AUTHOR]

In select cases of locally advanced cervical cancer, a hybrid brachytherapy (HBT) approach consisting of a combined intracavitary (IC)/insterstitial (IS) implant can yield improved target coverage and/or decreased organ at risk dose compared to IC techniques while limiting invasiveness compared to IS techniques. The technique involves placement of transvaginal and/or perineal needles in addition to the tandem and ring/ovoids using either a specialized applicator or free-hand placement. Following applicator and needle placement, brachytherapy may then be planned using principles similar to IC or IS techniques. During treatment planning, it can be helpful to obtain both MRI and CT imaging, as plastic MRI-compatible needles do not show up well on MRI. In patients where acceptable target coverage cannot be achieved using IC alone or doses to nearby OAR are too high, HBT should be evaluated. HBT can improve both dose to target and OAR while sparing patients the morbidity of perineal template-based interstitial brachytherapy. Specific scenarios where HBT may be preferred include bulky residual primary tumor especially with poor response to EBRT, extension into the lateral parametrium, vaginal extension of tumor, and an asymmetric target. Use of HBT can typically permit extension of dose coverage by an additional 1–2 cm beyond what can be achieved with an IC alone technique. HBT allows for improved therapeutic ratio by improving target volume coverage and/or lowering doses to OARs. Brachytherapists should be trained on the practical aspects of administering HBT to be able to offer a less invasive and impactful treatment option when appropriate. [ABSTRACT FROM AUTHOR]

Brachytherapy irradiation carries risks of both bleeding and venous thromboembolism (VTE). No screening or management recommendations for VTE in this setting have been developed. Our study aims to understand the incidence of VTE, compile published anticoagulation guidelines, and call for future guidelines to address thromboprophylaxis in this population. A retrospective, single institution study of patients undergoing brachytherapy irradiation between 2012 and 2022 was undertaken. We analyzed 2 cohorts: 87 patients undergoing brachytherapy with an inpatient admission, and 66 patients assessed for risk of VTE or bleeding after discharge from an inpatient admission for brachytherapy. Caprini risk scores were calculated for each patient, and statistical analyses were performed. Eighty-seven patients were included, and 25% had a VTE diagnosis. Forty-seven (54%) of patients included underwent brachytherapy as definitive treatment of cervical cancer, and 16 (18%) received brachytherapy irradiation to treat recurrent endometrial cancer. In the cohort of 66 patients assessed for risk of VTE or bleeding after brachytherapy discharge, 23 (34.8%) were discharged with thromboprophylaxis, and 43 (65.2%) were discharged without thromboprophylaxis. None of the patients discharged on thromboprophylaxis were diagnosed with a VTE within 90 days of discharge after brachytherapy, whereas 3 of 43 (7%) discharged without thromboprophylaxis were diagnosed with a VTE, OR and 95% CI: 0.25 (0.01–5.29), p = 0.37. Of the 23 patients discharged on thromboprophylaxis, 1 was readmitted for bleeding OR and 95% CI: 5.8 (0.22–155.18), p = 0.29. The median Caprini score was 11. VTE is a common occurrence in patients undergoing brachytherapy. Patients undergoing brachytherapy irradiation who require inpatient admission represent a unique population, and specialty organizations should develop consensus recommendations to address these clinical challenges. [ABSTRACT FROM AUTHOR]

Target and organ delineation during prostate high-dose-rate (HDR) brachytherapy treatment planning can be improved by acquiring both a postimplant CT and MRI. However, this leads to a longer treatment delivery workflow and may introduce uncertainties due to anatomical motion between scans. We investigated the dosimetric and workflow impact of MRI synthesized from CT for prostate HDR brachytherapy. Seventy-eight CT and T2-weighted MRI datasets from patients treated with prostate HDR brachytherapy at our institution were retrospectively collected to train and validate our deep-learning-based image-synthesis method. Synthetic MRI was assessed against real MRI using the dice similarity coefficient (DSC) between prostate contours drawn using both image sets. The DSC between the same observer's synthetic and real MRI prostate contours was compared with the DSC between two different observers' real MRI prostate contours. New treatment plans were generated targeting the synthetic MRI-defined prostate and compared with the clinically delivered plans using target coverage and dose to critical organs. Variability between the same observer's prostate contours from synthetic and real MRI was not significantly different from the variability between different observer's prostate contours on real MRI. Synthetic MRI-planned target coverage was not significantly different from that of the clinically delivered plans. There were no increases above organ institutional dose constraints in the synthetic MRI plans. We developed and validated a method for synthesizing MRI from CT for prostate HDR brachytherapy treatment planning. Synthetic MRI use may lead to a workflow advantage and removal of CT-to-MRI registration uncertainty without loss of information needed for target delineation and treatment planning. [ABSTRACT FROM AUTHOR]

To study the effect of various dose-volume parameters on the severity of vaginal stricture (VS) and the correlation of the latter with the posterior-inferior border of symphysis (PIBS) points in locally advanced cervical cancer patients treated with concurrent chemoradiation and brachytherapy. A prospective study was done on 45 histologically proven locally advanced cervical cancer patients between January 2020 and March 2021. All of them were treated with concurrent chemoradiation with 6 MV photon linear accelerator to a dose of 45 Gy/25 fractions in 5 weeks. Twenty-three patients were treated with intracavitary brachytherapy with a dose of 7 Gy/fraction/week for three fractions. Twenty-two patients were treated with interstitial brachytherapy, with 6 Gy/fraction for four fractions, each fraction 6 h apart. Grading of VS was done as per Common Terminology Criteria for Adverse Events version 5. The median followup was 21.5 months. About 37.8% of patients had VS with a median duration of 8.0 months (4.0–12 months). About 22.2% had Grade 1, 6.7% had Grade 2, and 8.9% had Grade 3 toxicity. Doses at PIBS and PIBS−2 points had no correlation with vaginal toxicity, however, the dose at PIBS+2 was significantly associated with VS (p = 0.004). The treated length of the vagina at the time of brachytherapy (p = 0.001), initial tumor volume (p = 0.009), and vaginal involvement after completion of external beam radiotherapy (EBRT) (p = 0.01) were also statistically significant with the development of VS of Grade 2 or more. Dose at PIBS + 2, treated length of the vagina with brachytherapy, initial tumor volume, and post-EBRT vaginal involvement are strong predictors for the severity of VS. [ABSTRACT FROM AUTHOR]

Brachytherapy (BT) is integral in treatment of gynecological malignancies and is also an option for many other cancers. Data on training and proficiency levels of early career oncologists is limited. Like other continents a survey was conducted for early career oncologists in India. An online survey was conducted from November 2019 to February 2020, through Association of Radiation Oncologists of India (AROI) for early career radiation oncologists expected to be within 6 years of training. The survey used a 22 item questionnaire that was also used for European survey. Responses to individual statements were recorded on a 1–5 Likert-type scale. Descriptive statistics were used to describe proportions. One-hundred twenty-four (17%) of 700 recipients responded to the survey. Majority of the respondents (88%) stated that being able to perform BT at the end of their training was important. Two-thirds of the respondents (81/124) had performed >10 intracavitary procedure and 22.5% had performed >10 intracavitary-interstitial implants. Many respondents had not performed nongynecological procedure- breast (64%), prostate(82%), gastro-intestinal (47%). Respondents predicted that in next 10 years, the role of BT is likely to increase. Lack of dedicated curriculum and training was perceived as the greatest barriers to achieving independence in BT (58%). Respondents suggested that BT training should be prioritized during conferences (73%) and online teaching modules (56%), along with development of BT skills labs (65%). This survey identified a lack of proficiency in gynecological intracavitary-interstitial brachytherapy and non-gynecological brachytherapy, despite BT training being regarded as highly important. Dedicated programs, including standardized curriculum and assessment need to be developed for training early- career radiation oncologists in BT. [ABSTRACT FROM AUTHOR]

To analyze clinical outcomes of high-dose-rate (HDR) interstitial brachytherapy boost (ISBT) after external beam radiation therapy (EBRT) or chemoradiotherapy (CRT) for the treatment of anal canal cancers (ACC). A total of 78 patients with ACC were treated at our institution by ISBT. Local Control (LC), disease-free survival (DFS), overall survival (OS), colostomy-free survival (CFS) and toxicity rates were analyzed. With a median followup (FU) of 59.8 months (95% CI [55.8–64.2]), six (7.7%) local recurrences with 2 patients (2.6%) having persistent disease at 3 months were observed. The 5-year rate of LC for the entire population was 92% [83–96%]. The 5-year DFS rate was 86% [76–93%]. The 5-year OS was 96% [88–99%]. In the univariate analysis, chemotherapy was significantly associated with morbidity grade ≥2. Late digestive toxicity grade ≥3 was reported in 8.9% patients, 1 patient underwent colostomy due to toxicity. The 5-year CFS rate was 88% [79–94%]. HDR interstitial brachytherapy boost provide excellent rates of tumor control and colostomy-free survival with a favorable profile of GI toxicity. Continence in anal cancer survivors is a challenge and the boost technique must be discussed in a multidisciplinary approach as part of de-escalation treatments. [ABSTRACT FROM AUTHOR]

To provide a systematic review of the applications of 3D printing in gynecological brachytherapy. Peer-reviewed articles relating to additive manufacturing (3D printing) from the 34 million plus biomedical citations in National Center for Biotechnology Information (NCBI/PubMed), and 53 million records in Web of Science (Clarivate) were queried for 3D printing applications. The results were narrowed sequentially to, (1) all literature in 3D printing with final publications prior to July 2022 (in English, and excluding books, proceedings, and reviews), and then to applications in, (2) radiotherapy, (3) brachytherapy, (4) gynecological brachytherapy. Brachytherapy applications were reviewed and grouped by disease site, with gynecological applications additionally grouped by study type, methodology, delivery modality, and device type. From 47,541 3D printing citations, 96 publications met the inclusion criteria for brachytherapy, with gynecological clinical applications compromising the highest percentage (32%), followed by skin and surface (19%), and head and neck (9%). The distribution of delivery modalities was 58% for HDR (Ir-192), 35% for LDR (I-125), and 7% for other modalities. In gynecological brachytherapy, studies included design of patient specific applicators and templates, novel applicator designs, applicator additions, quality assurance and dosimetry devices, anthropomorphic gynecological applicators, and in-human clinical trials. Plots of year-to-year growth demonstrate a rapid nonlinear trend since 2014 due to the improving accessibility of low-cost 3D printers. Based on these publications, considerations for clinical use are provided. 3D printing has emerged as an important clinical technology enabling customized applicator and template designs, representing a major advancement in the methodology for implantation and delivery in gynecological brachytherapy. [ABSTRACT FROM AUTHOR]

To evaluate the impact of dwell time deviation constraint (DTDC) on the quality of IPSA-optimized treatment plans in comparison with graphical plans using plan quality scores (PQS). Seventy optimized plans (graphical & IPSA with different DTDC values) of ten cervical cancer patients were generated. Various DVH parameters like D 90 , V 100 , V 150 , V 200 , V 300 were compared to evaluate the impact of DTDC on target coverage and high dose regions inside target for different plans. Similarly, for the OAR dose, values of D 2cc were compared. Various planning parameters like CI, COIN, DHI, DNR, ODI, EI and gain factor (GF) for different OARs were calculated. Based on these indices a plan quality score (PQS) was formulated and calculated. PQS values were used to see the impact of DTDC on plan quality of IPSA in comparison with dosimetric quality of graphical plan. We have found that target coverage is similar for IPSA and graphically optimized treatment plans. However, dose homogeneity was improved in IPSA compared to graphical optimization whereas conformality was better in graphically optimized plans. OAR dose was less in IPSA plans. High-dose regions inside the target were also reduced in IPSA comparatively. However, IPSA plans optimized with various values of DTDC did not necessarily reduce high-dose regions beyond 0.6. Plan quality scores (PQS) were 6.31, 6.31, 6.34, and 6.17 for the graphically optimized plan, IPSA with DTDC values of 0.0, 0.4, and 1.0 respectively. We found that IPSA is dosimetrically advantageous over graphical optimization. IPSA with a DTDC value of 0.4 improved overall plan quality. However, DTDC value beyond 0.6 produces dosimetrically sub-optimal plans hence the use of DTDC should be very selective and limited. [ABSTRACT FROM AUTHOR]

To investigate the consistency between preoperative and postoperative dosimetry when 125I brachytherapy for brain tumors is performed with magnetic resonance (MR) guidance and a three-dimensional non co-planar template (3DNPT). Thirty patients with brain tumors (metastatic or gliomas) underwent radioactive 125I seed implantation. A preoperative treatment plan was determined with MR imaging, and the operation was done under 3DNPT assistance and MR guidance. The dosimetry was verified postoperatively based on postoperative CT–MR fusion images. Postoperative dosimetric parameters and implant quality indices were defined and compared with those in the preoperative treatment plan. Furthermore, a comparison of preoperative and postoperative doses to normal brain tissues and organs at risk was also performed. All mean postoperative dosimetries were calculated. Target coverage parameters D90, D100, %CTV100, %CTV150, and %CTV200 were 143.6 cGy, 76.6 cGy, 88.2%, 63.1%, and 41.4%, respectively. The values of implant quality indices CI, EI, and HI were 0.75, 0.14, and 0.28, respectively. No significant differences between most preoperative and postoperative dosimetric parameters were found (p > 0.05). The differences were also insignificant for organs at risk. Postoperative %CTV150 and %CTV200 were higher than the preoperative, whereas postoperative HI was significantly lower than in the treatment plan. Magnetic resonance guidance combined with 3DNPT allows accurate positioning and direction in 125I brachytherapy for brain tumors. However, seed distribution and dose homogeneity require further improvement. [ABSTRACT FROM AUTHOR]

To establish a simulation-based workshop for teaching hybrid intracavitary/interstitial (IC/IS) brachytherapy skills using a new, commercially available US/CT/MRI-compatible gynecologic phantom prototype. The VIOMERSE gynecological trainer phantom consisted of tissue-like colloid material and was US, CT, and MRI-compatible. We designed a hands-on workshop incorporating the phantom prototype to teach skills for hybrid IC/IS brachytherapy including pre-implant planning, procedural steps of implant placement, and post-implant evaluation. The workshop impact was evaluated with pre- and post-workshop surveys and responses were analyzed with Wilcoxon matched-pairs signed-rank test. Thirteen residents, divided into small groups, attended one of three separate 1-h workshop sessions held during the gynecologic education block. Workshop steps included IC applicator placement, tumor mapping and pre-planning desired location and depth of needles for hybrid IC/IS application, IS needle labelling and insertion, image review of needle placements, comparison of IC-alone versus IC/IS brachytherapy plans. Responses to questions ascertaining knowledge, confidence, and ability in planning and executing hybrid IC/IS procedures all demonstrated significant improvement from pre- to post-workshop. In response to whether the session was an effective learning experience, all residents rated the workshop with a score of 9 (n = 1) or 10 (n = 12) out of 10, with a score of 10 indicating "strongly agree." Implementation of a hybrid IC/IS brachytherapy workshop utilizing a new, commercially-available phantom prototype was successful, with clear, subjective benefit for the residents in our program. This experience may inform continued efforts towards standardizing brachytherapy curricula across programs and increasing trainee exposure to interstitial procedures. [ABSTRACT FROM AUTHOR]

Brachytherapy (BT) for cervix cancer was listed as a level I priority and reduced number of implants and multiple fractions were recommended during COVID-19 pandemic. We present early clinical outcome of this approach. Patients treated with (chemo)radiotherapy and BT with single implant and multiple fractions BT were included. Treatment protocol included 3−5 fractions of 5−8.5 Gy with an aim to achieve point A dose of 70 Gy EQD2 10Gy (or HRCTV dose of >80 Gy EQD2 10Gy) in those undergoing intracavitary (IC) and HRCTV dose >85 Gy EQD2 10Gy in patients undergoing Intracavitary-Interstitial (IC/IS) whereas maintaining bladder (B2cc), rectum (R2cc), sigmoid (S 2cc) doses of 90, 75, and 75 Gy EQD2 3Gy. Time to event analysis was used to report oncological endpoints. Toxicity was reported using crude proportions. From April 2020 to March, 2021, 64 patients with stage IB2-IV received single implant and multi-fraction BT after external radiation of 45 Gy/25 fractions/5 weeks. Only 76.7% (n = 49) received concurrent chemotherapy. Median overall treatment time (OTT) was 56 days (38−131 days). Overall, 62.5% (n = 40) patients received IC and 37.5% (n = 24) received IC+IS. The median HRCTV was 34.7 cc (IQR 25−41). Median (IQR) point A dose, HRCTV D90, B2cc, R2cc, and S2cc for those undergoing IC was 74 Gy (71−78), 80 Gy (73−84), 86 Gy (82−89), 70 Gy (65−74), 65 Gy (59−73) respectively. For the IC+IS cohort, HRCTV D90, B2cc, R2cc, and S2cc was 84 Gy (78−89 Gy), 89 Gy (86−92), 70 Gy (67−74), 68 Gy (59−76). At a median follow-up of 16 months (5−27) the 2-year local control, pelvic control, cause specific and overall survival was 88%, 85.3%, 92.2%, and 81.3% respectively. Late gastrointestinal and genitourinary grade ≥III toxicities were 14% and 1.5% each. Abbreviated BT outcomes are encouraging for oncological outcomes despite delays in overall treatment time and omission of chemotherapy. Further mature follow up is needed. [ABSTRACT FROM AUTHOR]

This study aimed to determine the effectiveness of brachytherapy in post-operative cervical cancer patients with risk factors other than positive stump, and to identify the candidates most likely to benefit. Newly diagnosed, non-metastatic cervical cancer patients treated in our hospital between January 2012 and November 2015 were retrospectively reviewed. Early stage patients receiving radical surgery and needing adjuvant external radiotherapy were included, but those with positive stump were excluded. All patients received external radiotherapy. They were divided into two groups: one group received vaginal brachytherapy and the other did not. The 5-year local-regional recurrence free survival (LRRFS) and overall survival (OS) rates in the two groups were compared. Two hundred and twenty-five patients were included in this study; while 99 received brachytherapy, 126 did not. The brachytherapy group had significantly superior 5-year LRRFS (87.7% vs. 72.5%, p = 0.004), but did not show a significant overall survival benefit (78.4% vs. 75.3%, p = 0.055). In multivariate analysis, brachytherapy, pathological type, high-risk factors, duration of radiotherapy, and transfusion were independent prognostic factors for 5-year LRRFS. In stratified analysis, the brachytherapy group showed superior LRRFS in those meeting Sedlis criteria (p = 0.017). The combination of external beam radiation therapy and brachytherapy can improve LRRFS in post-operative cervical cancer patients with risk factors other than positive stump. Therefore, brachytherapy should be considered for these patients. [ABSTRACT FROM AUTHOR]

Standard practice entails employing multifractionated high-dose-rate (HDR) BT, administered in 3 to 4 sessions over 3 weeks post Chemoradiation, keeping overall treatment time < 56 days. Mono-application fractionated brachytherapy accelerates the treatment timeline without escalating acute or late toxicities. Recent progress in image-guided brachytherapy in cervical cancer facilitates the attainment of optimal dose volume parameters for both the target and organs at risk. This is the first multinational, multi-institutional study comparing outcomes and toxicity of mono-application fractionated brachytherapy versus multiple-application brachytherapy in carcinoma cervix. Enrolled 401 eligible patients with confirmed cervical cancer, FIGO stages IIA-IVA, intended definitive chemoradiation. Patients post 45-50 Gy external radiation with cisplatin either received mono-application fractionated brachytherapy or multiple-application for interstitial or intracavitary BT. Rectal and bladder doses were strictly maintained within 50% of prescription dose with adequate dosing to high-risk target volume. Demographic data, stage, histology, external radiation dose, brachytherapy dose and fractionation, D2 cc doses to bladder, rectum were recorded. Disease free survival and overall survival at 3 years were obtained along with data on acute and long-term bladder and rectal toxicities. Four hundred one patients, 203 received multiple applications spaced over 3 weeks and 198 received single application multiple deliveries < 48 hours. All patients underwent Intracavitary or Interstitial BT with most common fractionation of 7 Gyx3 or equivalent. Rectal and bladder 2 cc doses were 45% +/- 12% of prescription dose. HRCTV coverage of D90 of 95+/-7 was achieved in all cases. With a median follow up of 36 months (range = 22-37), 3 year disease-free was 0.78 and 0.76, The P value of 0.98 (> 0.05), showed difference in DFS between the two groups was not statistically significant. The 3-year overall survival was 0.72 and 0.71, P value of 0.1 (> 0.05), again statistically insignificant. Cox regression model analysis showed stage wise DFS and OS difference between the groups weren't statistically significant, hence proving the non-inferiority. The 3 year Grade 2 or more bladder and rectal toxicity has been reported in 2.3% and 4.1% in mono application group and 2.9% and 6.3% of multi-application group, statistically insignificant, confirming the credibility of our approach. Our study lays the foundation for a comprehensive investigation into the outcomes and efficacy of mono-application fractionated brachytherapy being non inferior to multiple-application with respect to outcomes and toxicity, providing valuable insights into the management of cervical cancer with reduced overall treatment time and superior resource management. Strict constraints to OARs and accuracy of image guided brachytherapy techniques, long term toxicity could be minimized. [ABSTRACT FROM AUTHOR]

Purpose: In cervical cancer brachytherapy, adding interstitial needles to intracavitary applicators can enhance dosimetry by improving target coverage while limiting normal tissue dose. However, its use is limited to a subset of practitioners with appropriate technical skill. We designed tandem anchored radially guiding interstitial templates (TARGITs) with a 3-dimensional (3D) printing workflow to optimize needle placement and facilitate greater ease-of-use of intracavitary/interstitial (IC/IS) technique. This study compared dosimetry and procedure characteristics between tandem and ovoid (T&O) implants using TARGIT technique versus non-TARGIT technique.Methods and Materials: This single-institution retrospective cohort study included patients undergoing T&O brachytherapy as part of definitive radiation treatment for cervical cancer between February 2017 and January 2021. TARGIT technique was implemented from November 2019 onwards; all prior procedures involved non-TARGIT technique using a no needle or freehand needle approach. Target coverage, dose to organs at risk, and procedure times were evaluated and compared between TARGIT technique and non-TARGIT technique.Results: The cohort included 70 patients with cervical cancer who underwent 302 T&O procedures: 68 (23%) with TARGIT technique and 234 (77%) with non-TARGIT technique, which included 133 no needle and 101 freehand needle implants. TARGIT implants involved longer average procedure times (+6.3 minutes, P < .0001). TARGIT implants achieved a higher mean high-risk clinical target volume V100% than non-TARGIT implants (+4.4%, P = .001), including for large tumors 30 cm3 or greater (+8.1%, P = .002). Average D90 was 4.6 Gy higher and average D98 was 3.2 Gy higher for TARGIT technique compared with non-TARGIT technique (P = .006 and P = .02). Total treatment doses to rectum, bowel, and bladder were not significantly different for TARGIT versus non-TARGIT technique.Conclusions: The 3D-printed TARGIT approach to T&O brachytherapy achieved greater tumor coverage while sparing normal tissues, particularly for large tumor volumes, with only a slight increase in average procedure time. TARGIT represents a creative technological solution for increasing accessibility of advanced IC/IS brachytherapy technique for cervical cancer definitive radiation treatment. [ABSTRACT FROM AUTHOR]

In the era of image guided radiotherapy and interstitial needle use, radiation dose to ureters can cause toxicity. A retrospective analysis of 106 patients with cervical cancer was performed to investigate ureter dose in brachytherapy patients. Re-optimization of brachytherapy treatment plans in 20 MRI planned patients was performed to reduce ureter dose whilst maintaining HRCTV D90 and OAR dose constraints. A total of 212 ureters were contoured and dose recorded. The crude incidence of ureteric stenosis was 6.6%. Ureter dose for all patients was 75.8 Gy and 74.4 Gy on the right and left respectively. A cohort of 20 MRI planned patients were reoptimized to reduce dose to ureters. Ureter dose was reduced from 91.1 Gy to 84.4 Gy and 73.9 Gy to 67.8 Gy on the right and left side respectively. A subgroup of patients with HRCTV D90 ≥84.3 Gy prior to reoptimisation saw a greater reduction in ureter dose of 13.3%. These were smaller tumours with better HRCTV coverage at the outset. Larger tumours with poorer HRCTV coverage (<84.3 Gy) saw a smaller reduction in ureter dose of 6.4%. Organ at risk dose to rectum, sigmoid and bladder were also significantly reduced. Patients treated with MRI guided brachytherapy and interstitial needles are at risk of ureteric stenosis. Contouring ureters and setting dose constraints should be considered to reduce ureteric dose while tracking HRCTV coverage [ABSTRACT FROM AUTHOR]

To automate the segmentation of treatment applicators on computed tomography (CT) images for high-dose-rate (HDR) brachytherapy prostate patients implanted with titanium needles with the goals of improving plan quality and reducing the patient's time under anesthesia. The investigation was performed using 57 retrospective, interstitial prostate treatments randomly assigned to training (n = 27), validation (n = 10), and testing (n = 20). Unique to this work, the CT image set was reformatted into 2D sagittal slices instead of the default axial orientation. A deep learning-based segmentation was performed using a 2D U-Net architecture followed by a density-based linkage clustering algorithm to classify individual catheters in 3D. Potential confounders, such as gold seeds and conjoined applicators with intersecting needle geometries, were corrected using a customized polynomial fitting algorithm. The geometric agreement of the automated digitization was evaluated against the clinically treated manual digitization to measure tip and shaft errors in the reconstruction. The proposed algorithm achieved tip and shaft agreements of -0.1 ± 0.6 mm (range -1.8 mm to 1.4 mm) and 0.13 ± 0.09 mm (maximum 0.96 mm), respectively on a data set with 20 patients and 353 total needles. Our method was able to separate all intersecting applicators reliably. The time to generate the automated applicator digitization averaged approximately 1 min. Using sagittal instead of axial images for 2D segmentation of interstitial brachytherapy applicators produced submillimeter agreement with manual segmentation. The automated digitization of interstitial applicators in prostate brachytherapy has the potential to improve quality and consistency while reducing the patient's time under anesthesia. [ABSTRACT FROM AUTHOR]

A pointwise encoding time reduction with radial acquisition (PETRA) sequence was optimized to detect empty catheters in interstitial (HDR) brachytherapy with clinically acceptable spatial accuracy for the first time. Image quality and catheter detectability were assessed in phantoms, and the feasibility of PETRA's clinical implementation was assessed on a gynecological cancer patient. Empty catheters embedded in a gelatin phantom displayed positive signal on PETRA and more accurate cross-sections than on clinically employed T2-weighted sequences, differing by 0.4 mm on average from their nominal 2 mm diameter. PETRA presented minimal susceptibility differences and a symmetric metal artifact, contrary to the clinical sequences. The PETRA-CT catheter tip position differences assessed by a treatment planning system (TPS) were < 1 mm. PETRA also detected an interstitial template with empty catheters penetrating a poultry phantom and fused very well with CT. Interstitial catheter positional difference between PETRA and CT images was < 1 mm on average, increasing with distance from isocenter. All interstitial catheters and the employed interstitial template were detected on PETRA images of an endometrial adenocarcinoma patient. Empty needles were traceable using a TPS, with higher spatial resolution and more favorable contrast than on T2-weighted images used for contouring. A treatment plan could be produced by combining information from PETRA for catheter detection and from T2-weighted images for tumor and organs delineation. PETRA detected successfully and accurately interstitial catheters in phantoms. Its first clinical implementation shows a potential for MR-only treatment planning in interstitial HDR brachytherapy. [ABSTRACT FROM AUTHOR]

• BT compares favorably with EBRT boost inanal cancer chemoradiation. • MRI-guided adaptive BT is expected to improve results further. • Some favorable physical & biological properties of BT cannot be matched by EBRT. • Despite this, the use of BT boost remains limited to selected centers. • BT boost for anal cancer should be reevaluated in a prospective clinical study. Evidence from studies which combined 2D-3D external beam radiotherapy (EBRT) ± chemotherapy with 2D brachytherapy (BT) for anal cancer suggest favorable outcomes when compared with chemo-EBRT alone. Further improvement of results can be expected in the era of intensity modulated EBRT and MRI-guided adaptive BT. Despite this, BT is not discussed as a therapeutic option in the prominent international guidelines and its use remains limited to selected institutions. Special skills, complexity, equipment, cost and reimbursement policies have been highlighted as barriers for its wider implementation. However, these factors are relevant for modern radiotherapy in general. Therefore, it can be argued that the role of BT as a component of chemoradiation should be redefined. We describe the historical evolution and current role of BT boost for anal cancer and outline its potential in the context of combined intensity modulated EBRT, chemotherapy and MRI-guided adaptive BT. [ABSTRACT FROM AUTHOR]

Intracavitary and/or interstitial brachytherapy is an integral component of the management of patients with central pelvic-recurrent cervical cancer after primary hysterectomy, and is typically delivered using conventional applicators. We investigated the efficacy and safety of three-dimensional (3D)-printed, customizable applicators for those patients. Twenty-six patients were treated with combination external beam radiotherapy and brachytherapy. Patients with lesions ≤1 and >1 cm before brachytherapy were treated with intracavitary and interstitial brachytherapy, respectively. Dosimetric plans were compared between the vaginal cylinder and 3D-printed applicator for the first 9 patients. Outcomes and treatment-related complications were also investigated. The median tumor size before brachytherapy was 0.81 cm. Intracavitary, interstitial, and combined interstitial-intracavitary brachytherapy were performed in 22 (85%), 3 (11%), and 1 (4%) of the patients, respectively. The clinical target volume (CTV) coverage goal was achieved with all 3D-printed plans but failed with three single-channel cylinder plans (33.3%). Owing to 3D-printed transvaginal applicator guidance, there was no need to adjust the needle position after implantation. The mean CTV dose for all patients was 71 ± 8.2 Gy; all met the dose constraints to the organs at risk, but 1 (4%) had a rectal D 2cc overdose. The 2-year local control, progression-free survival, and overall survival rates were 87.8%, 71.0%, and 91.6%, respectively. Four patients (21%) developed early grade 3–4 hematological toxicities and 1 (4%) developed a late grade 3 adverse event. High-quality intracavitary and/or interstitial brachytherapy can be achieved using a 3D-printed applicator and yields favorable outcomes with acceptable toxicity. [ABSTRACT FROM AUTHOR]

• The purpose of the paper is to update previously published GEC ESTRO guidelines for prostate brachytherapy. • Consensus guidelines are made for Low Dose Rate (LDR) and High Dose Rate (HDR) brachytherapy treatments. • New areas include the use of focal and salvage brachytherapy and the role of androgen deprivation therapy. This is an evidence-based guideline for prostate brachytherapy. Throughout levels of evidence quoted are those from the Oxford Centre for Evidence based Medicine (https://www.cebm.ox.ac.uk/resources/levels-of-evidence/oxford-centre-for-evidence-based-medicine-levels-of-evidence-march-2009). Prostate interstitial brachytherapy using either permanent or temporary implantation is an established and evolving treatment technique for non-metastatic prostate cancer. Permanent brachytherapy uses Low Dose Rate (LDR) sources, most commonly I-125, emitting photon radiation over months. Temporary brachytherapy involves first placing catheters within the prostate and, on confirmation of accurate positioning, temporarily introducing the radioactive source, generally High Dose Rate (HDR) radioactive sources of Ir-192 or less commonly Co-60. Pulsed dose rate (PDR) brachytherapy has also been used for prostate cancer [1] but few centres have adopted this approach. Previous GEC ESTRO recommendations have considered LDR and HDR separately [2–4] but as there is considerable overlap, this paper provides updated guidance for both treatment techniques. Prostate brachytherapy allows safe radiation dose escalation beyond that achieved using external beam radiotherapy alone as it has greater conformity around the prostate, sparing surrounding rectum, bladder, and penile bulb. In addition there are fewer issues with changes in prostate position during treatment delivery. Systematic review and randomised trials using both techniques as boost treatments demonstrate improved PSA control when compared to external beam radiotherapy alone [5–7]. [ABSTRACT FROM AUTHOR]

To determine the factors influencing the outcomes of patients with recurrences post-hysterectomy for cervical cancers treated with external beam radiotherapy (EBRT) and interstitial brachytherapy. This prospective study accrued 90 patients between October 2008 and May 2014. All patients had had a prior hysterectomy and were diagnosed with recurrent vaginal apex cancers with squamous cell carcinomas. All underwent EBRT of 50 Gy (2 Gy/fraction) using tomotherapy-based image-guided intensity-modulated radiotherapy with concurrent chemotherapy of weekly cisplatin (40 mg/m2) followed by high dose rate interstitial brachytherapy boost of 20 Gy (4 Gy/fraction twice a day). Local relapse, disease-free and overall survival were determined. At a median follow-up of 74 months (4–123 months), 10/90 (11%) patients had local failure as the first site of relapse and 12/90 (13.3%) had first distant relapse. Only one patient had synchronous local and distant relapse. The 7-year local relapse-free, disease-free and overall survival were 87.6, 68.3 and 68.3%, respectively. Grade 2 and 3 rectal toxicity were seen in 5.6 and 3.1% of patients, respectively. Among these, two (2.2%) patients underwent temporary diversion colostomy due to vaginal sigmoid and rectovaginal fistula. Grade 2 and 3 bladder toxicity were seen in 5.6 and 1.1% of patients, respectively. In summary, the lateral disease extent (P = 0.048) and the presence of nodal disease at diagnosis (P = 0.08) had a statistically significant or borderline impact on local relapse without any impact on disease-free survival. Tumour size in itself did not affect overall survival. With the integration of EBRT and interstitial brachytherapy, most vaginal apex recurrences can be salvaged. An excellent local control and survival is achievable using intensity-modulated radiotherapy with image guidance and concurrent chemotherapy followed by high dose rate interstitial brachytherapy. • We studied outcomes in patients with vaginal recurrences after surgery. • The study used IG-IMRT to reduce dose to organs at risk and escalate nodal dose. • Interstitial brachytherapy using perineal template to a dose of 20 Gy/5 fractions. • 7-year local relapse-free, disease-free and overall survival were 87.6, 68 and 68%, respectively. • Grade 3 rectal and bladder toxicity were seen in 3.1 and 1.1% of patients, respectively. [ABSTRACT FROM AUTHOR]

The purpose of study is to measure Point A pear-shaped isodose dimensions of the conventional intracavitary brachytherapy with various sizes of colpostats and analyze which size of tumor is the optimal for 3-D interstitial brachytherapy. CT simulation was performed with Fletcher type applicator using various sizes of colpostats (2.0, 2.5, and 3.0 cm diameter). The Manchester standard loading (dwell time) system was used to generate pear-shaped isodose envelopes with high-dose rate iridium-192 according to the colpostat sizes. The size of the pear-shaped envelope was measured at 5 different levels: A-level (center of the colpostats), B-level (top of the colpostats), C-level (between B and D), D-level (Point A), and E-level (1.0 cm above Point A). In this study, it was assumed that uterine tandem was located at the center of tumor. For width of pear-shape: At the A-level, 6.4, 7.3, and 8.0 cm for 2.0, 2.5, and 3.0 cm colpostats, respectively. At the B-level, 5.8, 6.4, and 6.8 cm for 2, 2.5, and 3.0 cm colpostats, respectively. At the C-level, 4.6, 4.8, and 4.8 for 2.0, 2.5, and 3.0 cm colpostats, respectively. At the D-level, 4.0 cm for all different size. At the E-level, 3.8 cm for all 3 different size colpostats. A-level was the largest dimension of pear-shape. However, it was located in the upper vagina below the main cervical mass. The center of the effective pear-shape size for tumor was between the C and D levels. For thickness, all 5 different levels were ranging 3.7 to 4.0 cm. For height, the length of height was dependent on the tandem length. Therefore, the pear-shape envelope was able to accommodate up to 4.0 cm diameter volume. According to our analysis of conventional pear-shape dimension, 3-D interstitial brachytherapy should be considered for tumors larger than 4.0 cm for symmetrical tumor. [ABSTRACT FROM AUTHOR]

Despite the excellent clinical outcomes from brachytherapy treatments compared with other modalities and the low associated costs, there have been reports of a decline in utilization of brachytherapy. The aim of this study was to investigate in detail the trend in utilization of brachytherapy in the province of Québec, Canada, from 2011 to 2019. All radiotherapy clinics in the province of Quebec, and among these the clinics that provide brachytherapy treatments, were identified. This observational retrospective cohort study involved analysis of data compiled by the Ministère de la Santé et des Services Sociaux du Québec for the period of 2011 to end of 2019 on all brachytherapy procedures performed in the province of Quebec. Time series graphs were used to describe the number of high dose rate (HDR) and low dose rate (LDR) brachytherapy treatments during the studied time period. Statistical analysis was conducted using R statistical software. Between 2011 and 2019, 12 hospitals in the province of Québec provided radiotherapy treatments, and all of them offered brachytherapy services. The median annual number of brachytherapy sessions was 4413 (range 3930-4829). HDR brachytherapy represented over 90% of all brachytherapy treatments throughout the study period. Significant changes over time were observed in the number of treatments: at least 5% change was seen only for the two most common subtypes of brachytherapy, HDR interstitial and HDR intracavitary, with an increase of 9.6% and a decrease of 9.2%, respectively. The use of other subtypes of brachytherapy (HDR-plesiotherapy, LDR-interstitial, LDR-intracavitary, LDR-eye plaque) was stable between 2011 and 2019, with ≤ 2.5% variation. This study demonstrates an overall steady use of brachytherapy between 2011 and 2019 in Quebec. Brachytherapy offers numerous advantages for the treatment of diverse cancer sites. Although more sophisticated external beam radiotherapy treatments have emerged in the last decades, the precision and cost-effectiveness of brachytherapy remain unbeaten. To ensure the continued use and availability of brachytherapy, governments must put in place policies and regulations to that effect. Training and exposure of future health care professionals to brachytherapy within Quebec and Canada is essential to provide all patients the same access to this life saving modality. [ABSTRACT FROM AUTHOR]

From both a disease and management perspective, locally advanced gynecologic cancers present a significant challenge. Dose escalation with brachytherapy serves as a key treatment, providing conformal radiation while sparing at-risk organs. Intracavitary brachytherapy techniques have been shown to be effective, with improving tumor control and toxicity profiles with the advent of three-dimensional image planning. Despite this, the variations in tumor size, location, and pelvic anatomy may lead to suboptimal dosimetry with standard intracavitary applicators in some clinical scenarios. The addition of interstitial needles (interstitial brachytherapy (interstitial brachytherapy) can improve the conformality of brachytherapy treatments by adding needles to peripheral (and central) regions of the target volume, improving the ability to escalate doses in these undercovered regions while sparing organs at risk. Interstitial brachytherapy can be delivered by intracavitary and interstitial hybrid applicators (ICBT/ISBT), perineal template (P-ISBT), or by free-hand technique. ISBT has however yet to be widely available because of concerns of complications and toxicities from this specialized treatment. However, with the increasing use of three-dimensional image-guided brachytherapy, there is an opportunity to increase the level of expertise in the gynecologic radiation oncology community with an improved understanding of the potential complications and morbidity. In this article, we review the acute and long-term toxicity in both ICBT/ISBT and P-ISBT using image-guided brachytherapy. [ABSTRACT FROM AUTHOR]

To characterize and report on dosimetric outcomes of image guided adaptive brachytherapy (IGABT) using intracavitary and interstitial (IC/IS) applicators including oblique needles (O-needles) in locally advanced cervical cancer (LACC). Twenty LACC patients treated with radio-chemotherapy and offered IC/IS-IGABT including O-needles were analyzed. An in-house 3D-printed vaginal template was used to steer the needles parallel and obliquely in relation to the tandem, supplemented with free-hand needles if needed. Implant characteristics and loading patterns were analyzed. Using the equivalent dose in 2Gy-fractions (EQD2) concept, cumulative (EBRT+BT) V85, V75, V60Gy, targets/OARs doses and high dose volumes (150%, 200% and 300% (100% = 85 Gy EQD2 10)) were evaluated. Median(range) tumor width at diagnosis was 5.5(3.6; 7.5)cm; CTV HR volume was 45(23; 136)cm3 with maximum distance from tandem to CTV HR border of 3.4(2.5; 4.8)cm. T-stage distribution was IIB/III/IVA in 6(30%)/9(45%)/5(25%) of patients. At BT, 13(65%) patients had distal parametrial/pelvic wall infiltration. Median(range) number of needles per patient was 11(8–18). Average distribution of intrauterine, vaginal and interstitial dwell times were 31%, 25% and 44%, respectively. Median(range) dwell-time per dwell position was 11(2–127)% of average point-A based standard loading. Median V 85Gy /V 150% /V 200% /V 300% were 85(38; 171)/41(21; 93)/22(12; 41)/7(4; 19) cm3; CTV HR D 90% was 93(83; 97)Gy EQD2 10 ; bladder/rectum/sigmoid/bowel D 2cm3 were 78(64; 104)/65(52; 76)/59(53; 69)/61(47; 76)Gy EQD2 3. The use of O-needles in patients with large and/or unfavorable tumors resulted in excellent target coverage and OARs sparing. Intrauterine and vaginal loadings were reduced compared to standard loading and almost half of the loading was shifted into IS needles. This was achieved with gentle loading in the majority of dwell positions. [ABSTRACT FROM AUTHOR]

To assess the relevance of virtual reality distraction (VR) during uterovaginal brachytherapy applicators' removal, as an alternative to nitrous oxide (N 2 O) conscious sedation, to decrease anxiety and pain perception. We prospectively evaluated 35 patients treated with cervical brachytherapy for locally or locally advanced cervical cancer. Brachytherapy applicators were removed in the patient's room at the end of the treatment. Patients were assigned to N 2 O conscious sedation (reference group) or VR (experimental group). Anxiety and pain were evaluated with the STAI-E score and with Visual Analogical Scales (VAS). Fourteen patients were treated with VR and 21 with N 2 O. STAI-E baselines scores were 35 in the VR group and 38 in the reference group and declined to 30 and 28, respectively after procedure. The mean VAS-anxiety was 2.9 before and 2.7 at the peak in the VR group versus 4.1 and 1.6, respectively in the reference group. The mean VAS-pain was 1.0 before, 3.1 at the peak and 0.4 after the procedure in the experimental group, versus 1.8, 2.0, and 0.6 respectively in the N 2 O group. Four patients in the VR group experienced mild nausea/vomiting or dizziness during the procedure. The preparation duration was higher in the VR group, with a similar duration for the removal itself. Replacing a medical gas by a virtual reality device was feasible and led to acceptable levels of pain and anxiety. Prospective randomized trials are needed to confirm efficacy and to determine which patients could benefit the most from this approach. [ABSTRACT FROM AUTHOR]

A growing number of patients with lung cancer are not amenable to surgery due to their age or comorbidities. For this reason, local ablative techniques have gained increasing interest recently in the management of inoperable lung tumors. High-dose-rate percutaneous interstitial brachytherapy, performed under CT-guidance, is a newer form of brachytherapy and is a highly conformal radiotherapy technique. The aim of this study was to describe this method and review the existing literature. Eight articles comprising 234 patients reported toxicity and clinical outcome. The follow-up ranged from 6 to 28 months. Diverse fractionation schemes were reported, with 20 Gy in a single fraction being the most frequently utilized. Toxicity was limited; major pneumothoraces occurred after only 8% of the interventions. Local control rates at one year ranged between 37% and 91%. In conclusion, high-dose-rate percutaneous interstitial brachytherapy is a safe, fast, and efficient treatment option for inoperable lung tumors. [ABSTRACT FROM AUTHOR]

Image guided adaptive brachytherapy, the standard treatment for locally advanced cervical cancer (LACC), is a complex medical procedure that requires an experienced multidisciplinary team. The aims of this analysis were to assess (1) the learning curve of brachytherapy team, (2) dose-volume parameters, (3) the use of an interstitial component, and (4) the overall treatment time (OTT). Our study cohort comprised 117 LACC patients treated in Kuopio University Hospital with magnetic resonance imaging guided intracavitary (IC) or combined intracavitary/interstitial (IC/IS) high dose rate brachytherapy during 2009-2018. Target volumes and organs at risk (OAR) were contoured according to ICRU/GEC-ESTRO recommendations. Treatment plans were optimized individually without using standard loading patterns. Mean dose to 90% of the high-risk clinical target volume (HR-CTV D90) improved after the first 15 patients, however the team's learning curve to reliably fulfill the main planning aim (PA) of 85 Gy required a total 43 patients and more than 10 patients annually. Significant difference was detected between IC and IC/IS brachytherapy in achieving the PA of HR-CTV D90. Especially, HR-CTV volumes >30 cm3 benefitted from IS needles. Needle insertion did not cause serious complications. With the brachytherapy program, the OTT of patients from outside institutions was reduced to the same level as our own patients. Brachytherapy requires good experience of multidisciplinary team and the continuous development of the program to fulfill PA and to avoid OTT prolongation. The use of IS needles is safe and improves the fulfillment of PA to target volume. [ABSTRACT FROM AUTHOR]

• In 54.8% of IOBT-performed patients, a histopathological R1 resection was found. • 58.3% of LARC patients are overtreated and 26.5% RRC patients are undertreated. • IOBT-performed patients reported more often acute pain grade I-II. • IOBT should be performed in RRC patients since it is their last resort. • IOBT-omitted patients lived significantly longer. A radical resection of locally advanced rectal cancer (LARC) or recurrent rectal cancer (RRC) can be challenging. In case of increased risk of an R1 resection, intra-operative brachytherapy (IOBT) can be applied. We evaluated the clinical selection strategy for IOBT. Between February 2007 and May 2018, 132 LARC/RRC patients who were scheduled for surgery with IOBT standby, were evaluated. By intra-operative inspection of the resection margin and MR imaging, it was determined whether a resection was presumed to be radical. Frozen sections were taken on indication. In case of a suspected R1 resection, IOBT (1 × 10 Gy) was applied. Histopathologic evaluation, treatment and toxicity data were collected from medical records. Tumour was resected in 122 patients. IOBT was given in 42 patients of whom 54.8% (n = 23) had a histopathologically proven R1 resection. Of the 76 IOBT-omitted R0 resected patients, 17.1% (n = 13) had a histopathologically proven R1 resection. In 4 IOBT-omitted patients, a clinical R1/2 resection was seen. In total, correct clinical judgement occurred in 72.6% (n = 88) of patients. In LARC, 58.3% (n = 14) of patients were overtreated (R0, with IOBT) and 10.9% (n = 5) were undertreated (R1, without IOBT). In RRC, 26.5% (n = 9) of patients were undertreated. In total, correct clinical judgement occurred in 72.6% (n = 88). However, in 26.5% (n = 9) RRC patients, IOBT was unjustifiedly omitted. IOBT is accompanied by comparable and acceptable toxicity. Therefore, we recommend IOBT to all RRC patients at risk of an R1 resection as their salvage treatment. [ABSTRACT FROM AUTHOR]

The study is an audit of reporting dose and volume specifications as per the ICRU 58 for MUPIT-based interstitial brachytherapy in gynecological cancers. Correlation between total reference air kerma (TRAK) and isodose surface was also evaluated to understand the intensity of treatment in interstitial brachytherapy. Forty-two patients underwent HDR MUPIT-based interstitial brachytherapy 20 Gy in five fractions after EBRT during 2017–2019. Treated volume, high and low-dose regions, mean central dose, Dose Homogeneity Index (DHI), organ at risk doses, and TRAK values were computed. High-dose regions V150 mean was 12.4 cc and V200 was 4.58 cc; and low-dose region was 75.92 cc. The mean treated volume was 59.8 cc. The mean central dose was 3.7 Gy. DHI was 79%. The mean D2cm3 bladder and rectum were 2.9 Gy and 2.8 Gy. The mean TRAK was 0.16 cGy per fraction per hour at 1 m. TRAK values showed significant correlation with various isodose volumes (TRAK and V100: r = 0.943 p < 0.0005; and TRAK and V50: r = 0.953; p < 0.0005). A positive correlation was observed between TRAK and the number of needles (r = 0.746; p < 0.0005). At a median followup of 16 months, 4 of 42 patients (9.5%) had local recurrences. Our study shows compliance with ICRU 58 recommendations along with certain deviations. Local recurrence rate is acceptable. TRAK shows correlation with surface isodose in MUPIT-based brachytherapy and should to be evaluated in future studies. [ABSTRACT FROM AUTHOR]

The purpose of the study was to develop a methodology for vaginal dose-surface maps (DSMs) in patients with cervix cancer and to investigate dose-surface histogram metrics as predictors for vaginal stenosis (St) and mucositis (Muc). Thirty-one patients with locally advanced cervix cancer with no vaginal St/Muc (CTCAE-v3) G ≥ 2 at baseline were analyzed. Patients were divided in four morbidity groups: 15 with St/Muc G0/1, 6 with St G ≥ 2, 4 with St/Muc G ≥ 2, and 6 with Muc G ≥ 2. Patients received external beam radiotherapy and 4-fraction intracavitary/interstitial high-dose-rate brachytherapy using tandem and ovoids. DSMs were generated from inner/outer vaginal surfaces. DSMs of external beam radiotherapy and brachytherapy (Gy EQD2 3) were added based on a system of homologous points, to generate cumulative DSMs. Dose-surface histogram/dose-volume histogram parameters, location of high/intermediate-dose regions, rectovaginal reference point, vaginal lateral 5 mm point doses, and vagina/implant dimensions were investigated for St and Muc prediction. Average/difference DSMs and one-way analysis of variance were used to compare between groups. Best predictors of stenosis were D 15–25cm2 and upper-vagina S 65–120Gy (%). Cutoffs of ∼90 Gy EQD2 3 for D 20cm2 and ∼80% for S 65Gy to top 3 cm inner vaginal surface suitably discriminated for stenosis. Spatial dose location on average/difference DSMs showed significantly higher doses (by > 20 Gy, p < 0.001) over longer parts of the dorsolateral vagina and higher rectovaginal reference point doses for any G ≥ 2 morbidity, over the whole circumference of the upper vagina for G ≥ 2 stenosis. Dose-volume histogram parameters were dependent on vaginal wall thickness. An increase of wall thickness from 2 to 4 mm resulted in an increase of D 2cm3 (D 4cm3) of 16% (32%). A novel method was developed to generate vaginal DSMs and spatial-dose metrics. DSMs were found to correlate with vaginal stenosis. The findings of this study are promising and should be further validated on a larger patient cohort, treated with different applicators. [ABSTRACT FROM AUTHOR]

Brachytherapy (BT) is a minimally invasive anticancer radiotherapeutic modality where the tumor is directly irradiated via a radioactive source that is precisely implanted in or adjacent to the tumor. BT for lung cancer may be conducted in the form of endobronchial BT and radioactive seed implantation (RSI-BT), mainly for nonsmall cell lung cancer (NSCLC). For patients with early-stage lung cancer who are not suitable for surgery or external beam radiotherapy (EBRT), BT may be used as an alternative treatment, and curative results could be achieved in certain patients with cancer confined to the trachea lumen. For patients with locally advanced/metastatic lung cancer, BT could be selectively applied alone or as a boost to EBRT, which could improve the local tumor control and patient's survival. In addition, BT is also useful as a salvage treatment in select patients with locally recurrent/residual lung cancer that failed other treatments (e.g., surgery, chemotherapy, and EBRT). However, clinical outcomes are mainly obtained from retrospective studies. Prospective studies are limited and needed. In recent years, the introduction of modern image guidance, novel radioactive seeds, BT treatment planning systems (BT-TPS), after-loading technique, and three-dimensional printing template (3D-PT) assistance, among others, have potentially improved the clinical outcomes of BT. However, a comprehensive review of BT with newly published literature was lacking. This review is to discuss BT for NSCLC based on recent literature published in PubMed. [ABSTRACT FROM AUTHOR]

Ways of the treatment of non-melanomas skin cancer are still under discussion. Recurrences after different modalities usage are still high. It applies to surgery, external irradiation and brachytherapy. Using brachytherapy, we can achieve very high local doses. Moreover, they can be higher, the lower the volume of irradiation. In this sense, brachytherapy has its own characteristics that greatly distinguish it from other approaches, but there are still many unresolved questions in brachytherapy itself. For example, irradiating the tumor with an application method or with injection applicators into the tumor, how to normalize the dose, adhering to the prescribed restrictions. The aim of the work was to compare the results of three brachytherapy methods in non melanoma skin cancer. We work at Microselectron, 30 channels. Planning of the isodose distribution is based on CT scans. 370 patients have been treated since 2012. Essential is the question of how many applicators to use and how to distribute them spatially. We use all available methods - iron needles and flexible applicators for interstitial brachytherapy, as well as application methods with individual masks and individual applicator placement. We use boluses to equalize the dose and the arrangement of applicators in several rows. A change in the location of the applicators changes something in the dose distribution that can be used to improve the distribution. That is, for example, to increase the dose value at the center of the tumor and increase the dose-fall gradient at the edges. When we use the applicator method with an individual mask our doses amounted to 36 Gy, 6 Gy, 6 fractions 5 times per week. The normalization of the dose depends on the tumor size, location and some other parameters. In the case of rigid needles insertion we prescribe 8 Gy twice per week, 4 fractions, total dose is equal to 32 Gy. In the case of intratissue irradiation with flexible applicators the total dose is equal to 42.5 Gy, 5.2 Gy, 8 fractions 5 times per week. Interstitial method is used as a rule in the case of volumetric tumors. Using iron needles has several advantages - extraction of needles takes place immediately after the delivery of dose in every fraction. The swelling disappears during one hour after extraction, and wound healing after irradiation happens faster. It is especially significant in treating eyelids. However, all three methods are comparable in results when the dose is properly normalized. We came to the conclusion that the choice of the method of irradiation, as well as the normalization of the dose in brachytherapy for non-melanoma skin cancer, depends mainly on the characteristics of the tumor and its location. [ABSTRACT FROM AUTHOR]

Development of brachytherapy template as a radiation treatment guidance device to localize deep seated tumors. The template of specific size and dimension were designed using solid modeling computer-aided design (Solid Works, Dassault systemes). The design was further converted to 3D printing readable format (. stl format). All the parts of the design were printed in 3D printer (Phrozen Technology, Taiwan) using stereolithography technology (SLA). A resin material in liquid form was laid on the 3D printer platform for printing. Lifting speed of the printing plate was set at 40 mm/min. The retract speed was 150 mm/min. The exposure time was set at 3.5 s. The newly designed template with all accessories were scanned in an X-ray CT scanner for imaging compatibility purpose. Scanning parameters were as follows: Tube Voltage - 120 kV, slice thickness - 2.0 mm, Tube Current - 305 mA, pixel size - 0.6738 x 0.7638 mm2 and etc. The overall process took 3 hours to print the design with printing resolution of 50 microns. Various parts of the design were produced in a layer-by-layer fashion. By photochemical process, the chosen resin material cross-linked together to form polymers. In the imaging study the Hounsfield unit (HU) value of the resin material for template design was found to be 250 HU. The newly printed template had angled holes around 80 degrees to insert and maneuver interstitial needles. The template design was built in such a way that obturators, rectal probe and related accessories were easily positioned and immobilized in the template capable of tumor localization in real clinical situation. A rectal probe was built as well with the base template. We are further developing a human pelvis phantom to test the efficacy of the new 3D printed template which we will show in our future studies. The ultimate goal of this study is to personalize patient treatment with an affordable and cost-effective solution. The newly designed template is capable of performing brachytherapy procedure. Further dosimetric validation study is required to explore the potential of the template for clinical use purpose. [ABSTRACT FROM AUTHOR]

Effective treatment for locally-advanced vulvar cancer remains a challenge and often requires multi-modality care. Unresectable disease may be managed with a combination of chemotherapy, external beam radiation (EBRT), and brachytherapy. Cesium-131 Low Dose Rate (LDR) interstitial brachytherapy is an effective modality to deliver high-quality localized radiation. This case report highlights the technique and efficacy of Cesium-131 LDR interstitial brachytherapy as a part of multimodal therapy in treating a medically inoperable patient with advanced age and multiple medical comorbidities. Patient is a 79-year-old female who presented with medically inoperable FIGO Stage IVA squamous cell carcinoma of the vulva with extensive left labial disease and circumferential extension into the upper vagina. In addition, patient had hypermetabolic left inguinal lymph node metastasis on PET/CT imaging. Patient was subsequently treated with EBRT (4930 cGy over 29 fractions was delivered to the vulva, vagina, and regional lymphatics, followed by a sequential boost of 1620 cGy over 9 fractions to the involved left inguinal lymph node) with concurrent weekly cisplatin. Following EBRT, the patient had residual disease burden. She was noted to have cobblestoning of the anterior vaginal wall extending laterally on both sides, with palpably bulky disease in roughly the 10 o'clock position along her right lateral vaginal wall. She was offered High Dose Rate (HDR) interstitial brachytherapy boost, but declined this treatment due to her age and multiple medical comorbidities. She was subsequently treated with Cesium-131 LDR interstitial brachytherapy. Cesium-131 interstitial free seeds were placed with the seed inserters starting proximally and extending distally along the anterior vaginal wall in a planer fashion. 3000 cGy was prescribed to the tumor using 28 sources, each with a strength 0.72 U per seed. Dose distribution is represented in Figure 1 (Coronal CT scan demonstrating the radiation dose distribution of Cesium-131 permanent LDR implant to gross residual vaginal disease following EBRT). This was followed by vaginal cylinder HDR intracavitary brachytherapy utilizing Iridium-192 (800 cGy was prescribed at 5 mm depth from the vaginal cylinder surface delivered over 2 fractions). PET/CT done at 3 months showed complete metabolic resolution of all disease without evidence of recurrent or metastatic disease. At the patient's 21-month follow up, she had no evidence of disease on clinical exam or PET/CT imaging at that time. Acute toxicities included CTCAE grade 2-3 vulvar and inguinal skin erythema and mild diarrhea. Late toxicities include vaginal wall fibrosis at the site of Cesium-131 implant. Cesium-131 LDR interstitial brachytherapy implementation in a multimodal therapy setting is proved to be a feasible and promising treatment option to achieve long-term local control in a medically inoperable patient with an extensive vulvovaginal neoplasm. This study demonstrates a proof of concept of the safety and viability of Cesium-131 LDR interstitial brachytherapy for definitive management in selective patient populations. Future research is warranted. [ABSTRACT FROM AUTHOR]

Addressing religion and spirituality (R/S) in the patient care setting can improve coping with illness, decrease rates of depression, increase compliance, improve patient hope, quality of life, and the patient-provider relationship. Given that gynecologic brachytherapy treatments often lead to increased stress and fear among patients, we assessed the incorporation of R/S in order to improve patient-physician communication. The FICA spirituality history taking tool outlines four domains for patient spiritual assessment: F aith or belief, I mportance of spirituality on an individual's life and health care decision making, individual's spiritual C ommunity; and interventions to A ddress spiritual needs. Utilizing the FICA questionnaire, we evaluated the importance of addressing R/S and assessed which specific FICA questions are most meaningful to gynecologic cancer patients undergoing radiation therapy. Six patients with gynecologic malignancy that have undergone external beam radiation or brachytherapy were verbally asked the FICA questionnaire with a translator used for two patients (Spanish and Benghali). Results were recorded by a single reviewer. Patients were asked to answer the FICA questions, then quantify each question as 0 (unhelpful) or 1 (helpful), and ultimately to select one question they perceived to be the most critical and would best open the conversation with providers. The average age of patients was 59 (range 37 - 74). They included three Christian Catholic patients, one identifying as Caucasian, another Black and the third Hispanic, one Tibetan Buddhist, one Jewish, and one Muslim patient. Diagnoses included early stage endometrial cancer (3 patients), metastatic endometrial cancer (1 patient), locally recurrent endometrial cancer (1 patient), and locally advanced cervical cancer (1 patient). Patients were treated with either vaginal cuff brachytherapy alone (3 patients), vaginal cuff brachytherapy followed by subsequent EBRT for metastatic disease (1 patient), pelvic RT (1 patient), or pelvic RT and syed interstitial brachytherapy (1 patient). Five out of six patients (83%) rated faith/belief as very important in their life, rated 5/5 (0 - not important to 5 - very important) and one patient rated 2-3/5. Five out of six patients (83%) would like their health care provider to address their spirituality during their care. Four patients (67%) reported that their beliefs played an important role in their health care decision making.The average number of questions patients thought to be helpful if asked by providers was 9.5 out of 11 questions (range 7-11). All six patients considered the following questions to be helpful if asked by providers: Do you consider yourself spiritual or religious? Do you have spiritual beliefs that help you cope with stress? What importance does your faith or belief have in your life? Have your beliefs influenced you in how you handle stress? Is there a group of people you really love, or who are important to you? How would you like your health care provider to use this information about your spirituality as they care for you? Four out of six patients (67%) chose a question that addresses spiritual beliefs in handling stress as the most meaningful in order to facilitate a conversation with providers. In this exploratory group of gynecologic cancer patients undergoing radiation therapy, conversations regarding religion and spirituality were highly coveted across a spectrum of demographics. The majority of patients rated faith/belief as very important in their life and wanted their healthcare provider to address their spirituality during their care. Implementing a spiritual assessment enhances the doctor-patient relationship and opens up further conversation about stress, coping, and the anxiety during gynecologic treatments. [ABSTRACT FROM AUTHOR]

Cervical cancer is the most common cancer treated at Gaborone Private Hospital (GPH), the only facility offering radiotherapy services in Botswana. For curative intent, patients receive concurrent chemoradiation followed by brachytherapy boost. Brachytherapy services commenced in Botswana in 2012, and treatment began by using traditional A points for planning. A successful brachytherapy project was established with mentorship by clinicians from Massachusetts General Hospital and the University of Pennsylvania. In 2021, GPH acquired a new HDR brachytherapy unit with interstitial ability. The Oncologist was sent on a brachytherapy training course (ESTRO, September 2022). We now use adaptive image guided brachytherapy with CT based planning. Initial challenges included: fear of beginning such a project, inadequate skill in whole team, inadequate time to conduct interstitial techniques and planning, lack of pre-brachytherapy imaging, and no access to general anesthesia. We report our experience in initiating adaptive HDR-brachytherapy in a resource-limited setting to assist in spreading knowledge and avert fears on performance of HDR-brachytherapy in similar settings. We retrospectively reviewed the records of ten patients treated with interstitial brachytherapy in January, 2023. January was selected for analysis as it represents the highest number of interstitial applications (10/29 patients - 35%). Medical records were reviewed to evaluate clinical and demographic information of the patients, treatment methods, and EQD2. Simple proportions and doismetric data are reported. (Table 1) Among ten patients treated with interstitial brachytherapy, 60% were stage 3, 70% were women living with HIV. Five (50%) were treated during the last week of EBRT and 50% were treated after completion of EBRT. Only three patients had pre-brachytherapy imaging, which was CT scan. Of the remaining seven patients, brachytherapy applicator choices were made based on clinical examination. Applicators were inserted under conscious sedation, prescribed by the Oncologist. All patients had an IV line inserted and were premeditated with Paracetamol 1g IV, Oxynorm 10 mg orally, Voltaren suppository and Bromazepam 3mg orally. Applicators were inserted under sterile conditions with a free draining urinary catheter. Tandem and ovoids were generally inserted blindly, and individual wires were pushed in under CT guidance. There was no ultrasound guidance. The highest number of wires inserted was 7. Treatment was well tolerated with no significant acute toxicities. All patients attained acceptable doses to HRCTV (D90> 85Gy EQD2). OARs were within tolerance. Note prolonged treatment time to completion was attributed to Linac downtime. In a limited resource setting without access to general anesthesia and routine CT imaging, we present a case series of interstitial brachytherapy patients with successful target dose coverage outcomes. We intent to conduct a prospective study to evaluate pain control during the procedures. Further evaluation of long term survival of these patients is warranted; however, this data is encouraging to help increase access to brachytherapy services for clinics and locations with limited access to specialty services. Training and mentorship are essential components of a successful project and it is hoped that brachytherapy training programs could be availed in Africa. [ABSTRACT FROM AUTHOR]

Brachytherapy (BT) after surgical resection of keloids reduces the risk of local recurrence, but standardization of dose/technique is lacking. Typical keloid BT treatment utilizes a single-channel source prescribed to 5-mm depth. We investigated the dosimetry of a volume-based target definition for interstitial high-dose-rate BT treatment of keloids. We retrospectively identified consecutive 14 patients who had a total of 20 keloids treated with interstitial high-dose-rate BT for keloids at our institution between 2004 and 2014. Keloids were treated with a single 8 Gy fraction prescribed to 5 mm beneath the scar within 36 h of surgery. Retrospectively, a 3-mm skin high-risk clinical target volume (HR-CTV) was contoured under the scar for volume-based dose calculations. Mean (SD) HR-CTV was 3.91 cm3 (3.1) and mean (SD) HR-CTV dose was 11.3 Gy (3.6). Mean D 90 (SD) was 62.9% (25.8) and mean V 100 (SD) was 56.5% (26.4). The mean V 150 (SD), V 200 (SD), and V 300 (SD) were as follows: 37.6% (19.9), 25.1% (14.4), and 11.3% (6.5), respectively. No local failures were reported at 9 months median followup. There were no Grade 2 or higher late toxicities. Using a volume-based target definition, a wide range of target coverage was observed. This is likely a consequence of the curvature of the skin and the challenges of keeping the catheter equidistant from the skin across the target. Additional data are needed to define the potential clinical impact on outcomes/toxicities of dosimetric correlates with single-catheter BT keloid treatment. [ABSTRACT FROM AUTHOR]

The purpose of the study was to report dosimetric differences for breast brachytherapy plans optimized for clinical target volume (CTV) generated using conventional isotropic expansion of tumor bed volume (TBV) and Groupe Européen de Curiethérapie–European Society for Radiotherapy and Oncology (GEC-ESTRO) recommendations to expand the TBV anisotropically to achieve a total safety margin of 2 cm (resection margin size + added safety margin). Institutional records of 100 patients who underwent accelerated partial breast irradiation using multicatheter interstitial brachytherapy from May 2015 to March 2020 were reviewed retrospectively. Two sets of CT-based plans were made, one with 1-cm isotropic margins around the tumor bed (CTV_ISO) and the other with anisotropic margins (CTV_GEC). Plans were evaluated and compared using the American Brachytherapy Society and GEC-ESTRO guidelines. The median TBV was 36.97 cc. The median margin widths were as follows: anterior 1.2, posterior 1.0, superior 1.0, inferior 0.9, medial 1.2, and lateral 1.2 cm. The mean tumor bed coverage index was 0.94; 0.93 [ p.066], the CTV coverage index 0.86; 0.84 [ p 0.001], the dose homogeneity index (DHI) 0.77; 0.75 [ p < 0.001] and the conformity index 0.66; 0.64 [ p < 0.001] in CTV_ISO and CTV_GEC plans, respectively. In smaller volume implants (TBV< 35 cc), the DHI was 0.76; 0.75 [ p 0.008] and the conformity index was 0.66; 0.62 [ p < 0.001], whereas in larger volumes >35 cc, the CTV coverage index was 0.86; 0.84 [ p 0.003] and the DHI 0.78; 0.76 [ p 0.001] in CTV_ISO and CTV_GEC plans, respectively. In this cohort of patients who underwent accelerated partial breast irradiation, plans with anisotropic margins had lower conformity, the impact of which was predominantly seen in smaller implants. Rest of the dosimetric constraints were achieved in both the plans as per the American Brachytherapy Society and GEC-ESTRO guidelines. [ABSTRACT FROM AUTHOR]

As the utilization of brachytherapy procedures continues to decline in clinics, a need for accessible training tools is required to help bridge the gap between resident comfort in brachytherapy training and clinical practice. To improve the quality of intracavitary and interstitial high-dose-rate brachytherapy education, a multimaterial, modular, three-dimensionally printed pelvic phantom prototype simulating normal and cervical pathological conditions has been developed. Patient anatomy was derived from pelvic CT and MRI scans from 50 representative patients diagnosed with localized cervical cancer. Dimensions measured from patients' uterine body and uterine canal sizes were used to construct a variety of uteri based off of the averages and standard deviations of the subjects in our study. Soft-tissue anatomy was three-dimensionally printed using Agilus blends (shore 30 and 70) and modular components using Vero (shore 85). The kit consists of four uteri, a standard bladder, a standard rectum, two embedded gross tumor volumes, and four clip-on gross tumor volume attachments. The three anteverted uteri in the kit are based on the smallest, the average, and the largest dimensions from our patient set, whereas the retroverted uterus assumes average dimensions. This educational high-dose-rate gynecological pelvic phantom is an accessible and cost-effective way to improve radiation oncology resident training in intracavitary/interstitial brachytherapy cases. Implementation of this phantom in resident education will allow for more thorough and comprehensive physician training through its ability to transform the patient scenario. It is expected that this tool will help improve confidence and efficiency when performing brachytherapy procedures in patients. [ABSTRACT FROM AUTHOR]

We sought to characterize temporal trends of radiation oncology resident–reported case experience with intracavitary brachytherapy (ICBT) and interstitial brachytherapy (ISBT). Summarized, deidentified case logs for graduating radiation oncology residents (GRORs) between 2007 and 2018 were obtained from the Accreditation Council for Graduate Medical Education national summary data report. Cases were subdivided based on the site of treatment. Analysis of variance was used to determine differences, and strength of association was evaluated using the Pearson correlation. The number of GRORs increased by 66% from 114 in 2007 to 189 in 2018 (p < 0.001). Average number of gynecologic ICBT cases per GROR increased, from 39.6 in 2007 to 48.7 in 2018 (p < 0.005). Average number of ISBT cases per GROR decreased, from 34.5 to 20.6 (p < 0.001), due to decreasing prostate volume, from 21.5 to 12 (p < 0.001). Experience with gynecologic ISBT cases remained low at an average of 4.5 cases per year. The average number of ICBT cases per GROR has increased, although this does not differentiate between cylinder and tandem-based insertions currently. There has been a steady decline in ISBT experience. These findings may have implications for the development of Accreditation Council for Graduate Medical Education case minimums for residency programs. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the use of a semiautomatic algorithm to simultaneously segment multiple high-dose-rate (HDR) gynecologic interstitial brachytherapy (ISBT) needles in three-dimensional (3D) transvaginal ultrasound (TVUS) images, with the aim of providing a clinically useful tool for intraoperative implant assessment. A needle segmentation algorithm previously developed for HDR prostate brachytherapy was adapted and extended to 3D TVUS images from gynecologic ISBT patients with vaginal tumors. Two patients were used for refining/validating the modified algorithm and five patients (8–12 needles/patient) were reserved as an unseen test data set. The images were filtered to enhance needle edges, using intensity peaks to generate feature points, and leveraged the randomized 3D Hough transform to identify candidate needle trajectories. Algorithmic segmentations were compared against manual segmentations and calculated dwell positions were evaluated. All 50 test data set needles were successfully segmented with 96% of algorithmically segmented needles having angular differences <3° compared with manually segmented needles and the maximum Euclidean distance was <2.1 mm. The median distance between corresponding dwell positions was 0.77 mm with 86% of needles having maximum differences <3 mm. The mean segmentation time using the algorithm was <30 s/patient. We successfully segmented multiple needles simultaneously in intraoperative 3D TVUS images from gynecologic HDR-ISBT patients with vaginal tumors and demonstrated the robustness of the algorithmic approach to image artifacts. This method provided accurate segmentations within a clinically efficient timeframe, providing the potential to be translated into intraoperative clinical use for implant assessment. [ABSTRACT FROM AUTHOR]

Because of the critical role of brachytherapy in the management of a variety of cancers, it is important for institutions to consider offering brachytherapy if appropriate staff and personal protective equipment are available for the protection of patients and staff. Albuquerque, B.A. Hrycushko, M.M. Harkenrider, Compendium of fractionation choices for gynecologic HDR brachytherapy-an American brachytherapy society Task group report. 11, 2012, 68-75 25 A.S. Taggar, T. Phan, L. Traptow, Cervical cancer brachytherapy in Canada: A focus on interstitial brachytherapy utilization. 105, 2019, 1005-1011 69 E.C. Rijkmans, A. Cats, R.A. Nout, Endorectal brachytherapy boost after external beam radiation therapy in elderly or medically inoperable patients with rectal cancer: Primary outcomes of the phase 1 HERBERT study. [Extracted from the article]

High-dose-rate (HDR) brachytherapy is a convenient treatment option for selected patients with T1-T2 penile squamous cell carcinoma (SCC), providing high rates of penile preservation and tumor control. We present the results of penile SCC treated with HDR brachytherapy either interstitially or via a surface mold. Between November 2009 and April 2019, seven patients (2 T1a and 5 T2) were treated with interstitial HDR and 8 (1 Tis, six T1a, and one T1b) with surface mold. Prescribed dose for interstitial patients ranged from 38.4 Gy in 6 days (3.2 Gy × 12) to 53 Gy in 9 days (3.12 × 17), BID. All patients treated with mold brachytherapy received 40 Gy in 10 fractions BID. Toxicity and oncological results were assessed for both groups, and their relation with dosimetry is described. Median follow up was 90 months for interstitial and 27 months for those treated with surface mold. Fourteen of 15 patients are alive and disease-free; one surface mold patient died of non-small-cell lung cancer. There was one relapse in each group, each treated with salvage penectomy. The potency was preserved in 82%. For interstitial, G2 necrosis occurred in 43%, G2 meatal stenosis in 29% and G3 stenosis in 14%. Both techniques have excellent rates of tumor control and organ preservation. Implant geometry and homogeneity constraints must be carefully designed to minimize toxicity in interstitial brachytherapy. Urethral contouring and reporting of dosimetric parameters should be defined. [ABSTRACT FROM AUTHOR]

The aim of the study was to compare the dose distributions of combined intracavitary and interstitial (IC/IS) brachytherapy with 3-catheter IC brachytherapy in treating locally advanced (stage IIB) cervical cancer. In total, 46 patients were included, each with stage IIB cervical cancer, local lesion sizes ≥5 cm, and tumors that had not regressed after 45 Gy/25 F external intensity-modulated radiotherapy. To identify the dosimetric advantage of delivering a local boost to high-risk (HR)-cervix in IC/IS, patients were divided into two groups: IC/IS and IC/IS + HR-cervix. The differences in dosimetric parameters were compared between the two groups. Comparisons were then made between the parameters of the four planning methods: IC (Point A), IC (three dimensional [3D]), IC/IS, and IC/IS + HR-cervix. In patients with IC/IS implants, the relative uterine tandem dwell time was significantly extended in the IC/IS + HR-cervix group, and the V150 and V200 volumes of HR-cervix were increased (all p < 0.001), whereas the D90 and D100 values of the IC/IS + HR-cervix group were lower than those in the IC/IS group. In pairwise comparisons, HR-cervix V150 and V200 values were lowest in the IC/IS group, followed by the IC (3D), IC/IS + HR-cervix, and IC (Point A) groups. All differences were statistically significant (p < 0.05), with the exception of IC/IS vs. IC (3D). When treating locally advanced cervical cancer (stage IIB, local residual volume ≥5 cm after external radiotherapy), the IC/IS + HR-cervix optimization method can meet the HR clinical target volume D90 dose requirement, normal tissue dose limits, and can escalate doses to local areas of the cervix. [ABSTRACT FROM AUTHOR]

Recurrent gynaecological tumours can cause significant morbidity with limited salvage options. This study investigates the strategy of salvage single-modality interstitial brachytherapy (SM-ISBT) for recurrent gynaecological pelvic cancer at two specialised ISBT centres. Patients who had received salvage SM-ISBT for pelvic recurrence of gynaecological cancers from September 2008 to January 2017 were included. None had distant metastasis at the time of recurrence. Local control, progression-free and overall survival and long-term toxicities were evaluated. Twenty-six patients with a median follow-up of 24 months (range 2.5–106.3 months) after SM-ISBT were included. Primary cancer sites were endometrium (20), cervix (4), vulva (1) and vagina (1). All patients had prior whole-pelvic external beam irradiation and 16 had prior brachytherapy. The median disease-free survival prior to SM-ISBT was 20.3 months (interquartile range 9.9–30.5). SM-ISBT was delivered with high dose rate technique over three to six fractions. The median high-risk clinical target volume was 34.6 cm3, with a median D90 of 29.1 Gy (range 16.1–64.6). The median bladder, rectum and sigmoid D2cm3 were 15.5, 18.7 and 3.7 Gy, respectively. After SM-ISBT, complete and partial responses were achieved in 17 (64%) and 5 (19%) patients, respectively. Two (7.4%) patients had grade 3 toxicities (both vaginal stenosis), with no grade 4 complications. Eighteen patients (69%) recurred, including local, regional and metastatic in 14 (54%), 8 (30%) and 5 (19%) patients, respectively. Two-year local control, progression-free survival and overall survival were 50, 38 and 78%, respectively. In follow-up, 12 patients (46%) remained in local control. Salvage SM-ISBT re-irradiation for pelvic recurrence of gynaecological malignancies was feasible and safe. With limited salvage options, the local control obtained in more than a quarter of patients seems reasonable. Further efforts are needed to establish a consensus about the optimal patient selection, dose fractionation, implant technique and combination with systemic therapies. • Single-modality brachytherapy is feasible for salvage re-irradiation in pelvis for gynaecological cancers. • It provides a 2-year local control of 50% and 2-year overall survival of 78%. • Toxicity profile is acceptable, with 7% grade 3 and no grade 4 toxicities. [ABSTRACT FROM AUTHOR]

Purpose: Organ preservation or nonoperative management of rectal cancer is of growing interest. Image guided adaptive endorectal brachytherapy is a radiation dose escalation modality: we explored its role in elderly patients unfit for surgery and patients refusing surgery.Methods and Materials: In this registry study, patients with rectal cancer who were ineligible for surgery received 40 Gy in 16 fractions of pelvic external beam radiation therapy. They subsequently received 3 weekly image guided adaptive brachytherapy boosts of 10 Gy to the residual tumor, for a total of 30 Gy in 3 fractions. Complete clinical response (cCR) and local control were the primary endpoints.Results: 94 patients were included; the median age was 81.1 years. With a median follow-up of 1.9 years, the proportion of cCR was 86.2%, the tumor regrowth proportion was 13.6%, and the cumulative incidence of local relapse was 2.7% at 1 year and 16.8% at 2 years. When considering responders and nonresponders, the 2-year local control was 71.5%. The overall survival at 2 years was 63.6%. Acute rectal grade 1 to 2 toxicity included all patients: 12.8% of patients had late bleeding requiring iron replacement, blood transfusions, or argon plasma therapy.Conclusions: Results of this registry study, evaluating radiation dose escalation for elderly medically unfit patients with unselected tumors, reveal that a high proportion of patients achieved cCR with a manageable toxicity profile. This technology will likely contribute to the challenging nonoperative management paradigm of rectal cancer. [ABSTRACT FROM AUTHOR]