Search

Objective: To develop and validate a novel scoring system for predicting the risk of uterine perforation during brachytherapy (BT) in cervical cancer patients and to stratify patients based on this score to guide the use of ultrasound guidance during BT. Methods: Fifty patients with uterine perforation during BT between January 2018 and December 2020 were included. Common reasons for perforation were identified and a scoring system was developed. This was then applied to a cohort of 50 patients without perforation. The 2 cohorts were compared using the χ² test. To validate the scoring system, all newly diagnosed patients who underwent BT in 2021 were scored, and analysed using χ2 test and receiver operator characteristic curves. Results: The mean score in the test cohort was 10.16 (range=7-14) and 5.92 (range=5-8) for patients with and without perforation. In the validation cohort, the mean score was 6.9 (range=5-10) and 9.33 (range=7-11) for those with and without perforation. Patients with a score <8 were classified as low risk, while those with a score =8 were classified as high risk. Among the criteria evaluated for validation, response to external beam radiotherapy, uterine position, cervico-uterine angle (uterine flexion), identification of cervical os at BT assessment, and the total score were significant predictors, while previous history of perforation, uterine length, and additional uterine anomaly were not. Conclusion: The novel scoring system is an effective predictor of perforation risk during BT. Implementing this during BT assessment can optimize the need for ultrasound guidance during the procedure. [ABSTRACT FROM AUTHOR]

We report an updated analysis of the outcomes and toxicities of MRI-based brachytherapy for locally advanced cervical cancer from a U.S. academic center. A retrospective review was performed on patients treated with MRI-based brachytherapy for cervical cancer. EBRT was standardly 45 Gy in 25 fractions with weekly cisplatin. MRI was performed with the brachytherapy applicator in situ. Dose specification was most commonly 7 Gy for 4 fractions with optimization aim of D90 HR-CTV EQD2 of 85–95 Gy α/β=10 Gy in 2 implants each delivering 2 fractions. Ninety-eight patients were included with median follow up of 24.5 months (IQR 11.9–39.8). Stage IIIA-IVB accounted for 31.6% of cases. Dosimetry results include median GTV D98 of 101.0 Gy (IQR 93.3–118.8) and HR-CTV D90 of 89 Gy (IQR 86.1–90.6). Median D2cc bladder, rectum, sigmoid, and bowel doses were 82.1 Gy (IQR 75.9–88.0), 65.9 Gy (IQR 59.6–71.2), 65.1 Gy (IQR 57.7–69.6), and 55 Gy (IQR 48.9–60.9). Chronic grade 3+ toxicities were seen in the bladder (8.2%), rectosigmoid (4.1%), and vagina (1.0%). Three-year LC, PFS, and OS were estimated to be 84%, 61.7%, and 76.1%, respectively. MRI-based brachytherapy demonstrates excellent local control and acceptable rates of high-grade morbidity. These results are possible in our population with relatively large volume primary tumors and extensive local disease. • Local control, overall survival, and progression-free survival at our institution are similar to larger studies. • Dose planning limits to organs-at-risk were met in a population with a higher proportion of stage IIIA-IVB patients. • Chronic grade 3+ toxicities were seen in 13.3% of patients, mostly in stage IIIB and IVA patients. [ABSTRACT FROM AUTHOR]

Background: Diffusion-weighted magnetic resonance imaging (DWI) provides a measurement of tumor cellularity. We evaluated the potential of apparent diffusion coefficient (ADC) values obtained from post-external beam radiation therapy (EBRT) DWI and prior to brachytherapy (BT) to predict for complete metabolic response (CMR) in bulky cervical cancer. Methods: Clinical and DWI (b value = 500 s/mm2) data were obtained from patients undergoing interstitial BT with high-risk clinical target volumes (HR-CTVs) > 30 cc. Volumes were contoured on co-registered T2 weighted images and 90th percentile ADC values were calculated. Patients were stratified by CMR (defined by PET-CT at three months post-BT). Relation of CMR with 90th percentile ADC values and other clinical factors (International Federation of Gynecology and Obstetrics (FIGO) stage, histology, tumor and HR-CTV size, pre-treatment hemoglobin, and age) was assessed both in univariate and multivariate logistic regression analyses. Youden's J statistic was used to identify a threshold value. Results: Among 45 patients, twenty-eight (62%) achieved a CMR. On univariate analysis for CMR, only 90th percentile ADC value was significant (p = 0.029) while other imaging and clinical factors were not. Borderline significant factors were HR-CTV size (p = 0.054) and number of chemotherapy cycles (p = 0.078). On multivariate analysis 90th percentile ADC (p < 0.0001) and HR-CTV size (p < 0.003) were highly significant. Patients with 90th percentile ADC values above 2.10 × 10− 3 mm2/s were 5.33 (95% CI, 1.35–24.4) times more likely to achieve CMR. Conclusions: Clinical DWI may serve to risk-stratify patients undergoing interstitial BT for bulky cervical cancer. [ABSTRACT FROM AUTHOR]

Cervical cancer is the second most common cancer cause of morbidity and mortality in Filipino women; the age‐standardized annual incidence is 15.2 as of March 2023. The majority are diagnosed at a locally advanced stage and in the reproductive and working age group. This results in important treatment and productivity costs. The importance of image‐guided and interstitial brachytherapy (BRT) in local control and toxicity outcomes has been shown in recent meta‐analyses. We review the status of advanced BRT program training and implementation in the Philippines and important challenges and opportunities to move forward. [ABSTRACT FROM AUTHOR]

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]

Background: High-dose-rate computed tomography (CT)-guided brachytherapy (HDR-BT) has shown promising results in patients with hepatocellular carcinoma (HCC). While growing evidence shows clear limitations of mRECIST, diffusion-weighted imaging (DWI) has relevant potential in improving the response assessment. Purpose: To assess whether DWI allows evaluation of short- and long-term tumor response in patients with HCC after HDR-BT. Material and Methods: A total of 22 patients with 11 non-responding HCCs (NR-HCC; local tumor recurrence within two years) and 24 responding HCCs (R-HCC; follow-up at least two years) were included in this retrospective bi-center study. HCCs were treated with HDR-BT and patients underwent pre- and post-interventional magnetic resonance imaging (MRI). Analyses of DWI were evaluated and compared between pre-interventional MRI, 1.follow-up after 3 months and 2.follow-up at the time of the local tumor recurrence (in NR-HCC) or after 12 months (in R-HCC). Results: ADCmean of R-HCC increased significantly after HDR-BT on the first and second follow-up (ADCmean: 0.87 ± 0.18 × 10−3 mm2/s [pre-interventional]: 1.14 ± 0.23 × 10−3 mm2/s [1. post-interventional]; 1.42 ± 0.32 × 10−3 mm2/s [2. post-interventional]; P < 0.001). ADCmean of NR-HCC did not show a significant increase from pre-intervention to 1. post-interventional MRI (ADCmean: 0.85 ± 0.24 × 10−3 mm2/s and 1.00 ± 0.30 × 10−3 mm2/s, respectively; P = 0.131). ADCmean increase was significant between pre-intervention and 2. follow-up (ADCmean: 1.03 ± 0.19 × 10−3 mm2/s; P = 0.018). There was no significant increase of ADCmean between the first and second follow-up. There was, however, a significant increase of ADCmin after 12 months (ADCmin: 0.87 ± 0.29 × 10−3 mm2/s) compared to pre-interventional MRI and first follow-up (P < 0.005) only in R-HCC. Conclusion: The tumor response after CT-guided HDR-BT was associated with a significantly higher increase in ADCmean and ADCmin in short- and long-term follow-up. [ABSTRACT FROM AUTHOR]

Background: Brachytherapy (BT) is a critical component of radiotherapy for locally advanced cervical cancer (LACC), and it has rapidly developed in recent decades. Since the advent of three-dimensional image-guided adaptive brachytherapy (3D-IGABT), magnetic resonance imaging (MRI) has emerged as the primary modality for image guidance. Meanwhile, other imaging modalities, such as computed tomography, 18F-fluorodeoxyglucose positron emission tomography, ultrasound, and their combinations have also been widely studied. Materials and methods: We reviewed studies on different imaging modalities utilized for target delineation and planning. Emerging techniques in IGABT like real-time image guidance and 3D printing were also included. We summarized research on their feasibility and concentrated on their clinical outcomes. Results: MRI-guided BT was the gold standard, and CT-guided BT was the most widely applied. Other modalities have shown feasibility and promising efficacy in dosimetry studies and preliminary outcomes. The longer-term clinical outcomes associated with these approaches require further elucidation. Conclusions: As 3D-IGABT was validated by promising clinical outcomes, the future of BT for LACC is expected to progress toward the refinement of more effective image-guided procedures. Moreover, achieving operational consensus and driving technological advancements to mitigate the inherent limitations associated with different imaging modes remain essential. [ABSTRACT FROM AUTHOR]

Purpose: Breast brachytherapy (BB) represents an important radiation therapy modality in modern breast cancer treatments. Currently, BB is mainly used for accelerated partial breast irradiation (APBI), local boost after whole breast radiation therapy (WBRT), and as salvage re-irradiation after second lumpectomy (APBrl). Two multi-catheter interstitial brachytherapy (MIB) techniques can be offered: intra-operative (IOB) and post-operative (POB) brachytherapy. The aim of this article was to summarize current available data on these two different brachytherapy approaches for breast cancer. Material and methods: A literature search was performed, and different experiences published by BB expert teams were analyzed and compared. These two different brachytherapy approaches for breast cancer have also been presented and discussed during meetings of the GEC-ESTRO BCWG. In addition, expert recommendations were defined. Results: A comprehensive description and practical comparison of both the techniques, i.e., IOB and POB, considering the latest available published data were presented. Different technical, logistic, and clinical aspects of both the methods were thoroughly examined and analyzed. This detailed comparison of the two breast brachytherapy techniques was supported by scientific data from extensive experience of experts, facilitating an objective analysis that, to our knowledge, has not been previously published. Conclusions: Based on the comprehensive analysis of both the brachytherapy techniques available, this article serves as a valuable resource to guide breast teams in selecting the optimal BB technique (POB or IOB), considering hospital environment, multi-disciplinary collaboration, and patient logistics. [ABSTRACT FROM AUTHOR]

Purpose: Brachytherapy plays a crucial role in the standard of care for locally advanced gynecological malignancies. In this report, we present the experience from a tertiary teaching hospital, which is a referral center for imageguided brachytherapy (IGBT) in the management of locally advanced gynecological malignancies. Material and methods: This was a retrospective study of 130 patients referred to our hospital for IGBT after receiving initial external beam radiotherapy in their primary healthcare facilities, from January 2021 till January 2023. CT-based planning was done to delineate high-risk clinical target volume (HR-CTV). Dose of 6-7.5 Gy in 3-4 fractions was prescribed. Overall treatment time (OTT) was calculated, and patients were assessed for clinical response and toxicity after three months. Results: All patients received IGBT using an intra-cavitary or interstitial technique. The D90 HR-CTV mean EQD2 dose was 28.34 ±2.78 Gy. The mean EQD2 dose to 2 cc of the bladder, rectum, and sigmoid was 18.31 ±5.19 Gy, 14.14 ±5.76 Gy, and 17.43 ±4.75 Gy, respectively. The median interval time between the last fraction of external beam radiation therapy (EBRT) and first evaluation in the hospital was 19 (range, 13-28) days (interquartile range [IQR]). The median time between the completion of chemoradiation and brachytherapy procedure was 25 (range, 19-33) days (IQR). The mean overall treatment time (OTT) was 63.5 ±14.7 days. Conclusions: This study highlights the established advantages of image-guided interstitial brachytherapy and associated challenges. To optimize the overall treatment duration, it is imperative to prioritize and update the referral processes for brachytherapy centers. [ABSTRACT FROM AUTHOR]

Curative-intent radiotherapy for locally advanced and select early stage cervical cancer in the US includes external beam radiotherapy (EBRT) with brachytherapy. Although there are guidelines for brachytherapy dose and fractionation regimens, there are limited data on practice patterns. This study aims to evaluate the contemporary utilization of cervical cancer brachytherapy in the US and its association with patient demographics and facility characteristics. We retrospectively analyzed clinical covariates of cervical cancer patients diagnosed and treated in 2018–2020 with curative-intent radiotherapy from the 2020 National Cancer Database. Associations between patient and institutional factors with the number of brachytherapy fractions were identified with logistic regression. Factors with association (p < 0.10) were then included in a multivariable logistic regression model. All tests were two-sided with significance <0.05 unless specified otherwise. Among the eligible 2517 patients, 97.3% received HDR or LDR and is further analyzed. More patients received HDR than LDR brachytherapy (98.9% vs 1.1%) and intracavitary than interstitial brachytherapy (86.4% vs 13.6%). The most common number of HDR fractions prescribed were 5 (51.0%), 4 (32.9%), and 3 (8.6%). After adjusting for the other variables in the model, ethnicity, private insurance status, overall insurance status, and facility type were the only factors that were significantly associated with the number of brachytherapy factions (p < 0.0001, p = 0.028, p = 0.001, and p < 0.0001, respectively, n = 2184). In the US, various HDR brachytherapy regimens are utilized depending on patient and institutional factors. Future research may optimize cervical cancer brachytherapy by correlating specific dose and fractionation regimens with patient outcomes. • Curative-intent radiotherapy for cervical cancer in the US may include external beam radiotherapy and brachytherapy. • This is the first assessment of physician practice pattern of curative-intent brachytherapy for cervical cancer in the US. • Most patients received HDR intracavitary brachytherapy and completed their radiotherapy as prescribed. • Patient ethnicity, insurance, and facility type are significantly associated with number of HDR brachytherapy fractions. [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]

Purpose: To present a new technique for the treatment of vaginal cuff recurrences using 3D-printed vaginal cylindrical template (3D-PVCT) with curved needle channels in brachytherapy. Material and methods: Two patients with vaginal cuff tumor treated with external beam radiotherapy and MRI-guided interstitial brachytherapy were selected for the present study. Prior to treatment, a vaginal cylinder with the same size as 3D-PVCT was inserted into the vagina. Magnetic resonance scan was performed to identify target volumes and organs at risk (OARs). By registration techniques, the implantation angle was determined, appropriate needle channels were selected, and the depth of each needle position was recorded. During the actual treatment, patients were under general anesthesia, and real-time guidance of trans-rectal ultrasound was applied referring to a pre-determined treatment plan. Results: For patient No. 1, 9 needles were inserted into the tumor, with 4 curved needle channels and 5 straight channels. For patient No. 2, 7 needles were inserted into the vaginal cuff tumor, with 6 curved needle channels and 1 straight channel. Doses delivered to volumes of targets and OARs for both patients met the EMBRACE II dose constraints. After follow-up of 15 and 18 months, respectively, both patients showed complete response, with no evidence of tumor recurrence. No significant acute or late toxicities were reported. Conclusions: With careful pre-planning, 3D-PVCT provides good target coverage and sparing of OARs. The results from these two patients indicate that this approach is very promising due to its flexibility and potential widespread application in the future. [ABSTRACT FROM AUTHOR]

Purpose: The addition of interstitial (IS) needles to intra-cavitary (IC) brachytherapy applicators is associated with improved outcomes in locally advanced cervical cancers involving parametrial tumor extensions. The purpose of this work was to validate a clinical workflow involving 3D-printed caps for a commercial IC split ring applicator that enable using IS needle trajectories tailored to each treatment. Material and methods: A dedicated software module was developed in this work allowing users to design patient-specific IS caps without knowledge of computer-aided design (CAD) software. This software module was integrated to 3D Brachy, a commercial software developed by Adaptiiv Medical Technologies Inc. For validation of the workflow, CAD models of ground truth caps with five IS needle trajectories were designed with Fusion 360™, 3D-printed, assembled with a split ring applicator, and CT-scanned with radio-opaque markers. 3D Brachy was then applied to generate a replica based on trajectories reconstructed from the radio-opaque markers. A comparison between ground truth and replicated IS needle trajectories was done using intersection points with planes at the level of the cervix (z = 0 cm) and a representative needle depth (z = 3 cm). Results: Prototypes of interstitial caps 3D-printed in both BioMed Amber and BioMed Clear SLA resins were tested to be functional both pre- and post-sterilization for IS needles with obliquity angles = 45°. Distance-to-agreement at z = 0 cm and 3 cm as well as deviations in pitch and yaw angles of the five IS needle trajectories were found to have mean values of 3.3 ±2.1 mm, 7.3 ±2.0 mm, 2.9° ±2.3°, and 7.0° ±7.0°, respectively. Conclusions: The clinical workflow for image-guided adaptive cervical cancer brachytherapy using the Montreal split ring applicator was validated. [ABSTRACT FROM AUTHOR]

Purpose: Although customized three-dimensional (3D) templates have shown advantages in brachytherapy, widespread application is still full of challenges. The present work proposed the use of a commercial 3D standardized template-guided intracavitary/interstitial brachytherapy (IC/ISBT) that could provide simple and reproducible needles' insertion. Material and methods: 43 patients received external beam radiotherapy (EBRT) with 45-50.4 Gy and subsequent IC/ISBT with 28 Gy in 4 fractions. In terms of IC/ISBT, 24 patients were treated with 3D standardized templates (ST group), and 19 patients were treated using free-hand implantation (FH group). Consistency of implantation for all needles and dosimetric differences for target and organs at risk (OARs) were then compared between two groups. Results: The mean variation of tip position between insertions for needles was 1.41 mm and 2.74 mm in ST group and FH group, respectively (p < 0.001). ST group was superior in terms of dosimetric conformity index (CI) and D90 for high-risk clinical target volume (HR-CTV), significantly improving to 23.21% (p < 0.001) and 3.58% (p = 0.031) compared with FH group. The D2cc of the bladder and sigmoid in the ST group were lower than those in the FH group (p < 0.05). Meanwhile, a strong correlation between the volume of HR-CTV and its CI in the ST group (R = 0.865, p < 0.001) was found with Spearman's correlation analysis. Conclusions: The implementation of 3D standardized template can potentially improve the precision and consistency in the needle insertion procedure that may replace some customized 3D templates, and achieve clinical satisfied dose distribution in IC/ISBT plans for patients with LACC. [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]

Purpose: To explore differences in dosimetry and planning parameters between intra-cavitary/interstitial interpolation (IC + ISBT) three-dimensional (3D)-printed template-based (3D-printed) and simple intra-cavity (ICBT) radiation techniques using a fixed Rotterdam three-tube applicator (TT) for computed tomography-guided high-dose-rate brachytherapy in locally advanced cervical cancer. Material and methods: This retrospective study included 100 patients (n = 50 each in 3D-printed and Rotterdam three-tube applicator treatment groups) with FIGO stages IIB-IVB cervical cancer from May 2019 to May 2022. Using high-risk clinical target volume, 377 of 400 plans categorized at intervals of 10 cm3 into 20-30, 30-40, 40-50, 50-60, 60-70, and 70-80 cm3; 23 plans with < 20 and > 80 cm³ volume were excluded. Dosimetry parameters (D90 and D98 of high-risk clinical target volume, and D2cc of organs at risk, including bladder, rectum, sigmoid, and bowel) and planning parameters (homogeneity index [HI], conformation number [CN], and organ at risk sparing factor) were compared between the two groups separately for six high-risk clinical target volume plan categories. Results: For the 3D-printing group, target coverage, organs at risk protection, and plan conformity and uniformity were better than those for the Rotterdam three-tube group. Particularly, in high-risk clinical target volume plans between 50-60 cm³, the mean D90 and D98 of high-risk clinical target volume were approximately 0.35 and 0.3 Gy higher, while the average D2cc of the bladder, rectum, sigmoid, and bowel were approximately 1.3, 0.9, 0.9, and 0.8 Gy significantly lower than those of the Rotterdam three-tube group, respectively (p < 0.05). The above-mentioned planning parameters differed significantly between the groups (p < 0.05). Conclusions: For the 3D-printing group, IC/ISBT reduced the dose for organs at risk while ensuring target coverage and conformation. This was especially noticeable for plans with high-risk clinical target volume of 50-60 cm³. [ABSTRACT FROM AUTHOR]

Background: Electromagnetic tracking (EMT) systems have been shown to provide valuable information on the geometry of catheter implants in breast cancer patients undergoing interstitial brachytherapy (iBT). In the context of an extended patient‐specific, pre‐treatment verification, EMT can play a key role in determining the potential need and, if applicable, the appropriate time for treatment adaptation. To detect dosimetric shortcomings the relative position between catheters, and target volume and critical structures must be known. Since EMT cannot provide the anatomical context and standard imaging techniques such as cone‐beam CT are not yet available in most brachytherapy suites, it is not possible to detect anatomic changes on a daily or fraction basis, so the need for adaptive planning cannot be identified. Purpose: The aim of this feasibility study is to develop and evaluate a technique capable of estimating follow‐up CTs at any time based on the initial treatment planning CT (PCT) and surrogate information about changes of the implant geometry from an EMT system. Methods: A deformation vector field is calculated from two different implant reconstructions acquired in treatment position through EMT, the first immediately after the PCT and the second at another time point during the course of treatment. The calculation is based on discrete displacement vectors of pairs of control and target points. These are extrapolated by means of different radial basis functions in order to cover the entire CT volume. The adequate parameters for the calculation of the deformation field were identified. By warping the PCT according to the deformation field, one obtains an estimated CT (ECT) that reflects the geometric changes. For the proof of concept, ECTs were computed for the time point of the clinical follow‐up CT (FCT) that is embedded in the treatment workflow after the fourth fraction. Results: ECT and clinical FCTs of 20 patients were compared to each other quantitatively in terms of absolute Hounsfield unit differences in the planning target volume (PTV) and in a convex hull (CH) enclosing the catheters. The median differences were 31.2 and 29.5 HU for the CH and the PTV, respectively. Conclusion: The proposed ECT approach was able to approximate the "anatomy of the day" and therefore, in principle, allows a dosimetric appraisal of the treatment plan quality before each fraction. In this way, it can contribute to a more detailed patient‐specific quality assurance in iBT of the breast and help to identify the timing for a potential treatment adaptation. [ABSTRACT FROM AUTHOR]

Background: Electromagnetic tracking (EMT) is a promising technology that holds great potential to advance patient‐specific pre‐treatment verification in interstitial brachytherapy (iBT). It allows easy determination of the implant geometry without line‐of‐sight restrictions and without dose exposure to the patient. What it cannot provide, however, is a link to anatomical landmarks, such as the exit points of catheters or needles on the skin surface. These landmarks are required for the registration of EMT data with other imaging modalities and for the detection of treatment errors such as incorrect indexer lengths, and catheter or needle shifts. Purpose: To develop an easily applicable method to detect reference points in the positional data of the trajectory of an EMT sensor, specifically the exit points of catheters in breast iBT, and to apply the approach to pre‐treatment error detection. Methods: Small metal objects were attached to catheter fixation buttons that rest against the breast surface to intentionally induce a local, spatially limited perturbation of the magnetic field on which the working principle of EMT relies. This perturbation can be sensed by the EMT sensor as it passes by, allowing it to localize the metal object and thus the catheter exit point. For the proof‐of‐concept, different small metal objects (magnets, washers, and bushes) and EMT sensor drive speeds were used to find the optimal parameters. The approach was then applied to treatment error detection and validated in‐vitro on a phantom. Lastly, the in‐vivo feasibility of the approach was tested on a patient cohort of four patients to assess the impact on the clinical workflow. Results: All investigated metal objects were able to measurably perturb the magnetic field, which resulted in missing sensor readings, that is two data gaps, one for the sensor moving towards the tip end and one when retracting from there. The size of the resulting data gaps varied depending on the choice of gap points used for calculation of the gap size; it was found that the start points of the gaps in both directions showed the smallest variability. The median size of data gaps was ⩽8 mm for all tested materials and sensor drive speeds. The variability of the determined object position was ⩽0.5 mm at a speed of 1.0 cm/s and ⩽0.7 mm at 2.5 cm/s, with an increase up to 2.3 mm at 5.0 cm/s. The in‐vitro validation of the error detection yielded a 100% detection rate for catheter shifts of ≥2.2 mm. All simulated wrong indexer lengths were correctly identified. The in‐vivo feasibility assessment showed that the metal objects did not interfere with the routine clinical workflow. Conclusions: The developed approach was able to successfully detect reference points in EMT data, which can be used for registration to other imaging modalities, but also for treatment error detection. It can thus advance the automation of patient‐specific, pre‐treatment quality assurance in iBT. [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]

Purpose: Interstitial brachytherapy (ISBT) is indicated for intact cervical carcinoma (IN-CC) if intracavitary brachytherapy (ICRT) is not feasible and also in vault carcinoma (VA-C). We aimed to evaluate the doses to pelvic lymph node regions in IN-CC and VA-C treated with ISBT. Material and methods: Ten patients (6 IN-CC, 4 VA-C) were chosen for this dosimetric study. IN-CC had a central tandem in addition to the needles. External iliac (EI-N), internal iliac (II-N), obturator (OB-N) and sacral (SA-N) groups of lymph nodes were delineated. A dose of 10 grays (Gy) and 8 Gy each x 2 fractions was prescribed to the target in IN-CC and VA-C respectively. Doses received by 100%, 90% and 50% volume (D100, D90, D50) and D2cc, D1cc, D0.1cc were evaluated. Doses to lymph nodal groups in IN-CC vs. VA-C were compared using Student's t-test. Results: For 20 implants, the median number of needles was 18 (range, 16-20). Mean D90 and D2cc of the combined bilateral OB-N, II-N, EI-N and SA-N groups were 33.62 ±3.46% and 102.94 ±10.71%, 6.98 ±0.65% and 39.69 ±3.64%, 5.1 ±0.51% and 15.4 ±0.8%, 7.76 ±0.95% and 15.36 ±1.09% of the prescribed doses respectively. Patients with a central tandem (IN-CC) received significantly higher doses to external, internal iliac and sacral group of lymph nodes (p < 0.001) as compared to VA-C. Conclusions: In patients with cervical carcinoma treated with ISBT, pelvic lymph node groups received significant doses. The dose contribution to pelvic lymph nodes is higher in patients with intact cervical cancer where a central tandem is used as compared to post-operative patients. [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]

Purpose: Advances in three-dimensional image-guided brachytherapy technique allow for using intra-cavitary, intra-cavitary and interstitial brachytherapy (ICIS-BT), and sole interstitial brachytherapy (ISBT) in addition to conventional intra-cavitary brachytherapy (ICBT). However, no consensus has been reached regarding the choice of these techniques. The aim of this study was to propose the size criteria for indication of interstitial techniques. Material and methods: We examined initial gross tumor volume (GTV) at presentation and at each brachytherapy session. Also, dose volume histogram parameters for each modality were compared in 112 patients with cervical cancer treated with brachytherapy (ICBT, 54; ICIS-BT, 11; and ISBT, 47).Results: The average GTV at diagnosis was 80.9 cm3 (range, 4.4-343.2 cm³), which shrank to 20.6 cm³ (25.5% of initial volume, range, 0.0-124.8 cm³) at initial brachytherapy. GTV > 30 cm³ at brachytherapy and high-risk clinical target volume > 40 cm³ were good threshold values for indication of interstitial technique, and tumors with initial GTV > 150 cm³ could be candidates for ISBT. An ISBT dose of 89.10 Gy can be prescribed in equivalent dose in 2 Gy fractions (range, 65.5-107.6 Gy), which was higher than those of ICIS (73.94 Gy, range, 71.44-82.50 Gy) and ICBT (72.83 Gy, range, 62.50-82.27 Gy) (p < 0.0001).Conclusions:Initial tumor volume is an important predictor for indication of ICBT and ICIS-BT. ISBT or at least an interstitial technique is recommended for initial GTV > 150 cm³. [ABSTRACT FROM AUTHOR]

Purpose: Treatment of recurrent brain metastases is extremely challenging. Here, we evaluated the feasibility and efficacy of an individualized three-dimensional template combined with MR-guided iodine-125 (125I) brachytherapy in the treatment of recurrent brain metastases. Material and methods: Twenty-eight patients with recurrent 38 brain metastases underwent 125I brachytherapy from December, 2017 to January, 2021. A pre-treatment brachytherapy plan and three-dimensional template were generated according to isovoxel T1-weighted MR images. 125I seeds were implanted under the guidance of three-dimensional template and 1.0-T open MR imaging. Dosimetry verification was performed based on CT/MR fusion images. Pre-operative and post-operative dosimetry parameters of D90, V100, and conformity index (CI) were compared. Overall response rate (ORR), disease control rate (DCR) at 6 months, and 1-year survival rate were calculated. Median overall survival (OS) measured from the date of 125I brachytherapy was estimated using Kaplan-Meier method. Results: No significant differences were observed between pre-operative and post-operative D90, V100, and CI values (p > 0.05). The ORR and DCR at 6 months were 91.3% and 95.7%, respectively. The 1-year survival rate was 57.1%. The median OS was 14.1 months. Two cases of minor hemorrhage and 5 cases of symptomatic brain edema were observed during the study. All clinical symptoms were alleviated after corticosteroid treatment applied for 7 to 14 days. Conclusions: A three-dimensional template combined with MR-guided 125I brachytherapy in the treatment of recurrent brain metastases is feasible, safe, and effective. This novel 125I brachytherapy strategy is an attractive alternative in the treatment of brain metastases. [ABSTRACT FROM AUTHOR]

Purpose: To compare inverse planning simulated annealing (IPSA) and hybrid inverse planning optimization (HIPO) using dosimetric and radiobiological models, and provide a basis for selecting the optimization method for cervical cancer. Material and methods: This was a retrospective study including 32 patients with radical cervical cancer. Brachytherapy treatment plans were re-optimized using IPSA, HIPO1 (with a locked uterine tube), and HIPO2 (with an unlocked uterine tube). Dosimetric data, including isodose lines, HR-CTV (D100, V150%, V200%, HI, and CI), and (bladder, rectum, and intestines) D1cc, D2cc for organs at risk (OARs) were also collected. Additionally, TCP, NTCP, BED, and EUBED were calculated, and differences were analyzed using matched samples t-test and Friedman test. Results: Compared with IPSA and HIPO2, HIPO1 had better V150% and V200% (p < 0.05). Compared with IPSA and HIPO1, HIPO2 had better D100 and CI (p < 0.05). The doses to the bladder D1cc (4.72 ±0.33 Gy)/D2cc (4.47 ±0.29 Gy) and rectum D1cc (4.50 ±0.61 Gy)/D2cc (4.11 ±0.63 Gy) were lower in HIPO2 than in IPSA and HIPO1. EUBEDs for HR-CTV were higher in HIPO1 and HIPO2 than in IPSA by 1.39-1.63%. However, TCPs were not remarkably different among the three plans (p > 0.05). Also, the NTCP for the bladder was lower in HIPO2 than in IPSA and HIPO1 by 13.04% and 16.67%, respectively. Conclusions: Although the dosimetric parameters of IPSA, HIPO1, and HIPO2 are comparable, HIPO2 provides better dose conformability and lower NTCP. Therefore, HIPO2 is recommended as an optimization algorithm in IC/ISBT for cervical cancer. [ABSTRACT FROM AUTHOR]

Purpose:To report the feasibility of performing hybrid intra-cavitary and interstitial (IC/IS) brachytherapy in patients with carcinoma cervix under trans-rectal ultrasound (TRUS) guidance. Material and methods: All patients who received an external beam radiotherapy (EBRT) dose of 50 Gy in 25 fractions with weekly chemotherapy, followed by a brachytherapy boost (21 Gy in 3 fractions) were prospectively included for analysis. IC/IS brachytherapy was performed using Fletcher style tandem and ovoid applicator with interstitial component under TRUS guidance. Parameters of implant quality analyzed included ability to insert tandem, ratio of needles loaded to the number of needles inserted, and incidence of uterine or organ at risk (OARs) perforation. Dosimetric parameters evaluated were dose to point A*, TRAK, D90 high-risk clinical target volume (HR-CTV), and D2cc to OARs (bladder, rectum, and sigmoid). Width and thickness of the target was compared between TRUS (TRUSw and TRUSt) and MRI (MRIw and MRIt).Results: Twenty carcinoma cervix patients treated with IC/IS brachytherapy were included for analysis. The mean HR-CTV volume was 36 cc. The median number of needles used were 6 (range, 2-10 needles). None of the patients had uterine perforation. Two patients had bowel and bladder perforation. The mean D90 HR-CTV and D98 HR-CTV were 87.3 Gy and 82 Gy EQD2, respectively. The mean D2cc to the bladder, rectum, and sigmoid were 80 Gy, 70 Gy, and 64 Gy EQD2, respectively. The mean dose to point A* was 70.4 Gy EQD2. The mean TRAK was 0.40. The mean TRUSw (±SD) and MRIw (±SD) were 4.58 cm (±0.44) and 4.49 cm (±0.50), respectively. The mean TRUSt (±SD) and MRIt (±SD) were 2.7 cm (±0.59) and 2.62 cm (±0.59), respectively. On statistical analysis, there was a significant correlation between TRUSw and MRIw (r = 0.93), and TRUSt and MRIt (r = 0.98).Conclusions: TRUS-guided IC/IS brachytherapy is feasible and provides adequate coverage of the target, with acceptable doses to OARs. [ABSTRACT FROM AUTHOR]

Purpose: This study retrospectively compared the clinical and toxicity outcomes for the cervical cancer of the MRI-guided two adaptive brachytherapy (IGABT) fractions versus one IGABT fraction in one application. Methods: One hundred and twenty patients with cervical cancer received external beam radiotherapy combined with or without concurrent chemotherapy, which was followed by the IGABT. The IGABT in 63 patients had one IGABT in each application (Arm 1), while in the other 57 patients, at least one treatment was two continuous IGABT every other day in one application (Arm 2). Clinical outcomes including overall survival (OS), cancer specific survival (CSS), progression free survival (PFS), local control (LC) were analyzed. Brachytherapy-related toxicities were evaluated, which included pain, dizziness, nausea/vomiting, fever/infection, blood loss during the removal of applicator and needles, the deep venous thrombosis, and other acute toxicities. The Common Terminology Criteria for Adverse Events (CTC-AE 5.0) was used to evaluate the incidence and severity of toxicities of the urinary system, lower digestive system, and reproduction system. Kaplan–Meier and the Log-rank test were used to analyze the clinical outcomes. Results: The median follow-up time of the patients in Arm 1 and Arm 2 was 23.5 and 12.0 months, respectively. The overall treatment time was significantly shorter in Arm 2 than Arm 1 (60 vs. 64 d; P = 0.017). The OS, CSS, PFS, and LC in Arm1 and Arm 2 was 77.8% vs. 86.0% (P = 0.632), 77.8% vs. 87.7% (P = 0.821), 68.3% vs. 70.2% (P = 0.207), and 92.1% vs. 94.7% (P = 0.583), respectively. The highest NRS of the pain during brachytherapy waiting period (2.22 ± 1.84 vs. 3.02 ± 1.65; P < 0.001) and at the time of the removal of the applicator (4.69 ± 1.49 vs. 5.30 ± 1.18; P < 0.001) in the patients who received one hybrid intracavitary and interstitial brachytherapy (IC/ISBT) in one application and two continuous IC/ISBT every other day in one application were significantly different. So far four patients with grade 3 late toxicities have been reported. Conclusions: The findings of this study demonstrated that the two continuous IGABT every other day in one application is a logistically applicable, safe, and effective treatment strategy that could shorten the overall treatment time and reduce the medical cost, comparing with the one IGABT in one application. [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]

Purpose: The purpose of this study was to investigate the precision of deep learning (DL)-based auto-reconstruction in localizing interstitial needles in post-operative cervical cancer brachytherapy (BT) using three-dimensional (3D) computed tomography (CT) images. Material and methods: A convolutional neural network (CNN) was developed and presented for automatic reconstruction of interstitial needles. Data of 70 post-operative cervical cancer patients who received CT-based BT were used to train and test this DL model. All patients were treated with three metallic needles. Dice similarity coefficient (DSC), 95% Hausdorff distance (95% HD), and Jaccard coefficient (JC) were applied to evaluate the geometric accuracy of auto-reconstruction for each needle. Dose-volume indexes (DVI) between manual and automatic methods were used to analyze the dosimetric difference. Correlation between geometric metrics and dosimetric difference was evaluated using Spearman correlation analysis. Results: The mean DSC values of DL-based model were 0.88, 0.89, and 0.90 for three metallic needles. Wilcoxon signed-rank test indicated no significant dosimetric differences in all BT planning structures between manual and automatic reconstruction methods (p > 0.05). Spearman correlation analysis demonstrated weak link between geometric metrics and dosimetry differences. Conclusions: DL-based reconstruction method can be used to precisely localize the interstitial needles in 3D-CT images. The proposed automatic approach could improve the consistency of treatment planning for post-operative cervical cancer brachytherapy. [ABSTRACT FROM AUTHOR]

Simple Summary: Two different prostate brachytherapy methods are applied to treat prostate cancer: either a permanent implant of low-dose-rate (LDR-BT) sources or a temporary implant of high-dose-rate (HDR-BT) sources. This study aimed to compare the dose distributions, specifically focusing on the impact of a prostate-rectum spacer and prostate volume. The prostate dose coverage was comparable between different techniques. HDR-BT was characterized by a considerably more homogenous dose distribution and lower doses to the urethra. The minimum dose of up to 5 mm from the prostate was higher for larger prostates. As a consequence of the hydrogel spacer in HDR-BT patients, the intraoperative rectum dose was considerably lower, especially in smaller prostates. However, prostate volume dose coverage was not improved. The dosimetric results explain the clinical differences between the techniques reported in the literature. The study aimed to compare the dose distribution in permanent low-dose-rate brachytherapy (LDR-BT) and high-dose-rate brachytherapy (HDR-BT), specifically focusing on the impact of a spacer and prostate volume. The relative dose distribution of 102 LDR-BT patients (prescription dose 145 Gy) at different intervals was compared with the dose distribution of 105 HDR-BT patients (232 HDR-BT fractions with prescription doses of 9 Gy, n = 151, or 11.5 Gy, n = 81). A hydrogel spacer (10 mL) was only injected before HDR-BT. For the analysis of dose coverage outside the prostate, a 5 mm margin was added to the prostate volume (PV+). Prostate V100 and D90 of HDR-BT and LDR-BT at different intervals were comparable. HDR-BT was characterized by a considerably more homogenous dose distribution and lower doses to the urethra. The minimum dose in 90% of PV+ was higher for larger prostates. As a consequence of the hydrogel spacer in HDR-BT patients, the intraoperative dose at the rectum was considerably lower, especially in smaller prostates. However, prostate volume dose coverage was not improved. The dosimetric results well explain clinical differences between these techniques reported in the literature review, specifically comparable tumor control, higher acute urinary toxicity rates in LDR-BT in comparison to HDR-BT, decreased rectal toxicity after spacer placement, and improved tumor control after HDR-BT in larger prostate volumes. [ABSTRACT FROM AUTHOR]

Objective. The feasibility of MRI-only treatment planning (MRTP) for interstitial high-dose rate (HDR) brachytherapy (BT) was investigated for patients diagnosed with gynecologic cancer. Approach. A clinical MRTP workflow utilizing a 'pointwise encoding time reduction with radial acquisition (PETRA)' sequence was proposed. This is a clinically available MRI sequence optimized to improve interstitial catheter-tissue contrast. Interstitial needles outside the obturator region were reconstructed using MR images only. For catheters penetrating through the obturator, a library-based reconstruction was proposed. In this work, dwell coordinates from the clinical CT-based reconstruction were used as the surrogate for the library-based approach. For MR-only plan, dwell times were activated and assigned as in the clinical plans. The catheter reconstruction was assessed by comparing dwell position coordinates. The dosimetric comparisons between a clinical plan and MR-only plan were assessed for physical and EQD2 dose and volume parameters for D 90, D 50 and D 98 for clinical target volume (CTV) and D 2cc, D 0.1cc and D 5cc for OARs. Main results. Catheter reconstruction was possible using the optimized PETRA sequence on MR images. An overall reconstruction difference of 1.7 ± 0.5 mm, attributed to registration-based errors, was found compared to the CT-based reconstruction. The MRTP workflow has the potential to generate a treatment plan with an equivalent dosimetric quality compared to the conventional CT/MRI-based approach. For CTV D 90, physical and EQD2 dose and volume parameter differences were 1.5 ± 1.9% and 0.7 ± 1.0 Gy, respectively. For D 2cc OARs, DVH (EQD2) differences were −0.4 ± 1.1% (−0.2 ± 0.5 Gy), 0.5 ± 2.8% (0.2 ± 1.3 Gy) and −0.5 ± 1.4% (−0.2 ± 0.5 Gy) for rectum, bladder, and sigmoid, respectively. Significance. With the proposed MRTP approach, CT imaging may no longer be needed in HDR BT for interstitial gynecologic treatment. A proof-of-concept study was conducted to demonstrated that MRTP using PETRA is feasible, with comparable dosimetric results to the conventional CT/MRI-based approach. [ABSTRACT FROM AUTHOR]

Purpose: Brachytherapy is a mandatory component of primary radiochemotherapy in cervical cancer. The dose can be applied with a traditional intracavitary approach (IC alone) or with multiple catheter brachytherapy to optimize dose distribution in an individual concept. We therefore evaluated whether the utilization of a tandem–ring applicator plus additional intracavitary applicators (add IC) provides an advantage over the traditional IC alone approach, as this method is less time consuming and less invasive compared to a combined intracavitary/interstitial brachytherapy. Methods: Twenty three procedures of intracavitary brachytherapy for cervical cancer with additional intracavitary applicators performed in seven patients treated between 2016 and 2018 in our institution were included in this study. Plans were optimized for D90 HR-CTV with and without the utilization of the additional applicators and compared by statistical analysis. Results: D90 for HR-CTV was 5.71 Gy (±1.17 Gy) for fractions optimized with add IC approach and 5.29 Gy (±1.24 Gy) for fractions without additional applicators (p < 0.01). This translates to a calculated mean EQD2 HR-CTV D90 of 80.72 Gy (±8.34 Gy) compared to 77.84 Gy (±8.49 Gy) after external beam therapy and four fractions of brachytherapy for add IC and IC alone, respectively (p < 0.01). The predictive value of improved coverage of HR-CTV in the first fraction was high. Conclusion: In a subgroup of cases, the addition of intracavitary Heyman capsules can be an alternative to interstitial brachytherapy to improve the plan quality compared to standard IC alone brachytherapy. The benefit from the addition of applicators in the first fraction is predictive for the following fractions. [ABSTRACT FROM AUTHOR]

Purpose: Pain control techniques during high-dose-rate hybrid intracavitary-interstitial brachytherapy (HBT) for cervical cancer vary widely, with many centers opting for general anesthesia (GA) or conscious sedation (CS). Here, we describe a single-institutional series of patients treated with HBT and ASA-defined minimal sedation, utilizing oral analgesic and anxiolytic medications in substitution for GA or CS. Material and methods: The charts of patients who underwent HBT treatments for cervical cancer from June 2018 to May 2020 were retrospectively reviewed. Prior to HBT, all patients underwent an exam under anesthesia (EUA), and Smit sleeve placement under general anesthesia or deep sedation. Oral lorazepam and oxycodone/acetaminophen were administered between 30-90 minutes before HBT procedure for minimal sedation. HBT placement was performed on computed tomography (CT) table, with needle advancement under CT-guidance. Results: Treatments with minimal sedation were attempted in 63 patients. A total of 244 interstitial implants with 453 needles were placed via CT-guidance. Sixty-one patients (96.8%) tolerated the procedure without any additional intervention, while two patients (3.2%) required the use of epidural anesthesia. None of the patients in the series required a transition to general anesthesia for the procedure. Bleeding, which resolved with short-term vaginal packing, occurred in 22.1% of insertions. Conclusions: In our series, the treatment of HBT for cervical cancer with minimal sedation was feasible at a high percentage (96.8%). The ability to perform HBT without GA or CS could be a reasonable option to provide image-guided adaptive brachytherapy (IGABT) with limited resources, allowing for more widespread use. Further investigations using this technique are warranted. [ABSTRACT FROM AUTHOR]

Purpose: We assessed prognostic factors of local control and progression-free survival (PFS) of patients treated for AJCC stages T1 and T2 cervical cancer using utero-vaginal brachytherapy after chemoradiotherapy. Material and methods: This retrospective single-institution analysis included patients who underwent brachytherapy after radiochemotherapy between 2005 and 2015 at the Institut de Cancérologie de Lorraine. Adjuvant hysterectomy was optional. A multivariate analysis of prognostic factors was carried out. Results: Of 218 patients, 81 (37.2%) were AJCC stage T1, and 137 (62.8%) were AJCC stage T2. 167 (76.6%) patients had squamous cell carcinoma, 97 (44.5%) patients had pelvic nodal disease, and 30 (13.8%) patients had para-aortic nodal disease. One hundred eighty-four patients (84.4%) underwent concomitant chemotherapy, while adjuvant surgery was performed in 91 patients (41.9%) and 42 (46.2%) patients had pathological complete response. Median follow-up was 4.2 years, and local control was reported in 87.8% (95% CI: 83.0-91.8) and 87.2% (95% CI: 82.3-91.3) of patients at 2 and 5 years, respectively. In multivariate analysis, T stage (hazard ratio [HR] = 3.65, 95% CI: 1.27-10.46, p = 0.016) was associated with local control. PFS was reported in 67.6% (95% CI: 60.9-73.4) and 57.4% (95% CI: 49.3-64.2) of patients at 2 and 5 years, respectively. In multivariate analysis, para-aortic nodal disease (HR = 2.03, 95% CI: 1.16-3.54, p = 0.012), pathological complete response (HR = 0.33, 95% CI: 0.15-0.73, p = 0.006), and intermediate-risk clinical tumor volume of > 60 cc (HR = 1.90, 95% CI: 1.22-2.98, p = 0.005) were associated with PFS. Conclusions: Lower dose brachytherapy may benefit AJCC stages T1 and T2 tumors, whereas higher doses are required for larger tumors and para-aortic nodal disease involvement, respectively. Pathological complete response should be associated with better local control and not surgery. [ABSTRACT FROM AUTHOR]

Purpose: To compare dosimetric parameters of brachytherapy (BT) treatment plans made with or without active source positions of the ring/ovoid (R/O) applicator in locally advanced cervical cancer patients. Material and methods: Sixty patients with cervical cancer without vaginal involvement were selected for the study, who received intra-cavitary/interstitial BT. For each patient, two plans with and without active source dwell positions in R/O were created, using the same dose-volume constraints. EQD2 total doses from external beam and BT of target volumes and organs at risk (OARs) between the competing plans were compared. Results: There was no significant difference in the dose of high-risk clinical target volume (HR-CTV) and gross tumor volume (GTV) between the plans with inactive vs. active R/O. The mean D98 of intermediate-risk clinical target volume (IR-CTV) was significantly lower with inactive R/O; however, the GEC-ESTRO (EMBRACE II study) and ABS criteria were fulfilled in 96% in both plans. There was no difference in dose homogeneity, but conformity of the plans with inactive R/O was higher. Doses to all OARs were significantly lower in plans without R/O activation. While all the plans without R/O activation fulfilled the recommended dose criteria for OARs, it was less achievable with R/O activation. Conclusions: Inactivation of R/O applicator results in similar dose coverage of the target volumes with lower doses to all OARs, as activation of R/O in cervix cancer patients when HR-CTV does not extend to R/O applicator. The use of active source positions in R/O shows worse performance regarding the fulfilment of the recommended criteria for OARs. [ABSTRACT FROM AUTHOR]

A novel clinical workflow utilizing a direction modulated brachytherapy (DMBT) tandem applicator in combination with a patient-specific, 3D printed vaginal needle-track template for an advanced image-guided adaptive interstitial brachytherapy of the cervix. The proposed workflow has three main steps: (1) pre-treatment MRI, (2) an initial optimization of the needle positions based on the DMBT tandem positioning and patient anatomy, and a subsequent inverse optimization using the combined DMBT tandem and needles, and (3) rapid 3D printing. We retrospectively re-planned five patient cases for two scenarios; one plan with the DMBT tandem (T) and ovoids (O) with the original needle (ND) positions (DMBT + O + ND) and another with the DMBT T&O and spatially reoptimized needles (OptN) positions (DMBT + O + OptN). All retrospectively reoptimized plans have been compared to the original plan (OP) as well. The accuracy of 3D printing was verified through the image registration between the planning CT and the CT of the 3D-printed template. The average difference in D2cc for the bladder, rectum, and sigmoid between the OPs and DMBT + O + OptNs were −8.03 ± 4.04%, −18.67 ± 5.07%, and −26.53 ± 4.85%, respectively. In addition, these average differences between the DMBT + O + ND and DMBT + O + OptNs were −2.55 ± 1.87%, −10.70 ± 3.45%, and −22.03 ± 6.01%, respectively. The benefits could be significant for the patients in terms of target coverage and normal tissue sparing and increase the optimality over free-hand needle positioning. [ABSTRACT FROM AUTHOR]

Uterine serous carcinoma is a rare but aggressive subtype of endometrial adenocarcinoma. Our objective was to compare adjuvant treatment strategies for patients with early stage uterine serous carcinoma. This multi-institutional, retrospective cohort study evaluated patients with early stage uterine serous carcinoma. Patients with FIGO Stage IA-II disease after surgery, whose tumors had serous or any mixed serous/non-serous histology were included. Patients with carcinosarcoma were excluded. Clinical data were abstracted from local medical records. Summary statistics, Fisher's exact, and Kruskal-Wallis tests were used to analyze demographic and clinical characteristics. Univariable and multivariable analyses were performed for recurrence-free and overall survival. There were 737 patients included. Most patients had Stage IA disease (75%), 49% of which had no myometrial invasion. Only 164 (24%) tumors had lymphatic/vascular space invasion. Adjuvant treatment varied: 22% received no adjuvant therapy, 17% had chemotherapy alone, 19% had cuff brachytherapy, 35% had cuff brachytherapy with chemotherapy, and 6% underwent pelvic radiation. Adjuvant treatment was significantly associated with a decreased risk of recurrence (p = 0.04). Compared with no adjuvant therapy, patients who received brachytherapy or brachytherapy/chemotherapy had improved recurrence-free survival (HR 0.59, 95% CI 0.40–0.86; HR 0.65, 95% CI 0.49–0.88, respectively) and overall survival (HR 0.53, 95% CI 0.35–0.79; HR 0.49, 95% CI 0.35–0.69, respectively). Improved survival with brachytherapy and brachytherapy/chemotherapy persisted on multivariable analyses. Chemotherapy alone was also associated with improved overall survival compared with no adjuvant treatment (HR 0.55, 95% CI 0.37–0.81). Adjuvant therapy was associated with a decreased risk of recurrence relative to observation alone. Adjuvant cuff brachytherapy with and without chemotherapy was associated with improved survival outcomes in patients with early stage uterine serous carcinoma. • Treatment approaches for patients with early stage uterine serous carcinoma vary. • Use of adjuvant therapy is associated with decreased risk of recurrence relative to surveillance. • Vaginal cuff brachytherapy both with and without chemotherapy is associated with improved survival outcomes. • Patients with early stage uterine serous carcinoma should be offered vaginal cuff brachytherapy. [ABSTRACT FROM AUTHOR]

Simple Summary: The recommended treatment for locally advanced cervical cancer (LACC) consists of chemoradiotherapy (CRT) followed by brachytherapy (BT). Although BT is considered a minimally invasive procedure, patients still suffer severe discomfort from it and risk uterine perforation. Dosimetric uncertainties are often inevitable due to anatomical variations and inconsistencies in applicator loadings. These issues prompted us to explore the use of stereotactic body radiotherapy (SBRT) as a viable alternative. It has been well described that the CyberKnife (CK), a robotic image-guided SBRT delivery system, is capable of producing rapidly fall-off dose gradients with submillimeter accuracy. The aim of this study was to compare the dose distributions and radiobiological effects of a CK-based SBRT boost and a BT boost. We found a tumor volume threshold target, below which the CK-based SBRT plan could result in significantly better target coverage, OAR sparing and radiobiological effects compared to the BT plan. With improved precision of target localization, a reduced PTV margin might increase the eligibility of patients to receive a CK-based SBRT boost after CRT, rather than BT. CK-based SBRT could be an alternative option for patients who are not candidate for BT. (1) Aim: To compare the treatment plans of stereotactic body radiotherapy (SBRT) with CyberKnife (CK) and high-dose-rate (HDR) intracavitary/interstitial brachytherapy (IC/ISBT) and examine the feasibility of CK-SBRT as a viable alternative to BT in patients with locally advanced cervical cancer (LACC). (2) Methods: A BT plan of 28 Gy in four fractions delivered previously to 20 patients with LACC was compared with a CK plan based on the same CT images with structures delineation for BT. The SBRT treatment plan was further divided according to two different approaches, with the high-risk planning target volume (HR-PTV) defined by the high-risk clinical target volume (HR-CTV) without and with a 5 mm margin, which were named CK-CTV plan and CK-PTV plan, respectively. The dose distributions and dosimetric parameters of the target volumes and organs at risk (OARs) were recorded and compared for the three boost plans. Radiobiological metrics were calculated based on the EUD for the hybrid plans. Additionally, the relationship between tumor volume and tolerance doses for the OARs in the BT plan and CK-PTV plan was investigated. (3) Results: Target coverage was better with the CK plan than with the BT plan, as the D95%, D98%, HI and CI of the CK-CTV plan and CK-PTV plan were higher than those of the BT plan; an exception was the D50%. Similarly, the TCP of the target was also significantly in favor of the CK hybrid plans (p < 0.01). For the OARs, the CK-CTV plan was superior to the BT plan as regards the rectum D2cc, bladder D2cc and bladder Dmax. The CK-PTV plan could achieve dosimetric parameters comparable to those of the BT plan for OARs concerning the small residual tumor volume. The NTCP of the rectum for the WPI+CK-CTV plans was significantly lower than that of the WPI+BT plans (p < 0.01). (4) Conclusions: CK-based SBRT can achieve better target coverage, dose sparing for the OARs and radiobiological effects compared with the BT plan for tumors that are not excessively large. CK-based SBRT could be an alternative option to administer a radiation boost for patients with LACC. [ABSTRACT FROM AUTHOR]

Background: Locoregional therapies, as imaging-guided tumor-directed procedures, are emerging treatment strategies in the management of primary and secondary liver malignancies such as e.g. colorectal cancer liver metastases. As one of those, irradiation-based interstitial high dose rate brachytherapy (iBT) of liver metastases bears a risk of developing focal radiation-induced liver injury (fRILI). Since little is known about biological factors involved in hepatic dysfunction after irradiation, the aim of this study was to identify factors, that may play a role in the underlying mechanism of fRILI, and that potentially may serve as biomarkers for post-therapeutic fRILI to improve specific management and treatment of patients. Methods: Twenty-two patients with hepatic malignancies (tumor patients, TP) underwent iBT with total ablative doses of radiation to the target volume ranging from e.g. 15 to 25 Gy. Hepatobiliary magnetic resonance imaging (MRI) was performed 6 weeks after iBT to quanitify fRILI. Blood samples were taken before (pre) and 6 weeks after (post) iBT from TP, and from ten healthy volunteers (HV controls) for the analyses of humoral mediators: monocyte chemoattractant protein-1 (MCP-1), chemokine (C-X3-C motif) ligand 1 (CX3CL1), vascular endothelial growth factor (VEGF) and beta-nerve growth factor (beta-NGF) using the Multi-Analyte Flow Assay via flow cytometry. Correlation analyses between the humoral mediators (pre and post iBT) with the tumor volume and fRILI were performed. Results: While MCP-1 and CX3CL1 tended to decrease in TP vs. HV, VEGF was significantly decreased in TP vs. HV pre and post iBT (p < 0.05). Beta-NGF levels were significantly increased in TP vs. HV pre and post iBT (p < 0.05). Baseline circulating levels of MCP-1, VEGF and beta-NGF have shown significant positive correlations with the hepatic tumor volume (p < 0.05). Circulating levels of humoral mediators before treatment did not correlate with fRILI, while CX3CL1 and VEGF after iBT have shown significant positive correlations with fRILI (p < 0.05). Conclusion: Tumor volume and threshold dose of irradiation damage correlated positively with MCP-1 and VEGF as well as NGF and CX3CL, respectively. Thus, investigation of biological mediators in blood samples from tumor patients may provide an appropriate tool to predict fRILI after interstitial HDR brachytherapy of liver metastases. [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]

Purpose: To evaluate the reliability of algebraic sum with respect to rigid fusion of treatment plans related to adjuvant external beam pelvic radiotherapy (APR) and vaginal cuff high-dose-rate brachytherapy (BT) in uterine cancer patients. Material and methods: For algebraic sum, APR and BT doses were mathematically added. Rigid fusion was realized overlapping computed tomography (CT) images of APR and BT treatment plans. Rectum and bladder were considered reference organs at risk (OARs). Following dose (D) parameters were examined: Dmax (0.5 cc), D20% and D50% for rectum, Dmax (0.5 cc) and D50% for bladder; for each parameter, differences between the two adopted methods were reported as Δ-values. Results: Twenty uterine cancer patients submitted to radical surgery followed by APR plus vaginal cuff BT were reviewed. APR was done with a dose of 25 × 2 Gy. All patients also receveid a vaginal cuff boost with BT at the dose of 2 × 5 Gy. Differences between mean cumulative doses calculated with rigid fusion and algebraic sum were evaluated. For the rectum and bladder ΔD50%, there were no significant differences, and BT contribution resulted minimal. An apparent significant difference value was registered in bladder ΔDmax (0.5 cc). No toxicity was observed. Conclusions: In uterine cancer patients submitted to APR and vaginal cuff BT, algebraic sum and rigid plan fusion of doses allowed to obtain similar results in evaluating cumulative OARs' doses. Further investigations and increased number of patients are recommended to confirm our findings. [ABSTRACT FROM AUTHOR]

Purpose: To compare the pre-plan and post-plan dosimetric parameter differences of 3D-printed non-coplanar templates (3D-PNCT)-assisted computed tomography (CT)-guided iodine-125 (125I) radioactive seed implantation brachytherapy (RISI) in patients with inguinal lymph node metastasis (ILNM). Material and methods: This was a retrospective study of 15 patients with ILNM carcinomas treated with 3D-PNCT-assisted CT-guided RISI between May, 2015 and April, 2018. All patients underwent prior external beam radiotherapy (EBRT) or surgery. Dosimetric parameters included D90, D100 (dose delivered to 90% and 100% of the volume, respectively), V100, V150, V200 (percentage of target volume receiving 100%, 150%, and 200% of the prescribed dose, respectively). Quality parameters included conformal index (CI), external index (EI), and homogeneity index (HI). Paired t-test and Bland-Altman analysis were applied to compared pre-plan and post-plan parameters. Results: The median gross tumor volume (GTV) in the pre-plan was 8.7 ml (range, 0.8-185.1 ml). There were statistically significant differences in V100, V150, CI, and EI (p < 0.05). Bland-Altman analysis indicated that accidental error of RISI was small. In 1 of the 15 cases, D90 and D100 exceeded the prescribed therapeutic accuracy. In 1 of the 15 cases, V150, EI, and GTV were outside the specified accuracy range (95% confidence interval). Conclusions: 3D-PNCT-assisted CT-guided RISI is a safe, accurate, and feasible choice in ILNM treatment. The procedure of RISI has significantly improved. The pre-plan can be accurately executed by 3D-PNCT-assisted CT-guided RISI. [ABSTRACT FROM AUTHOR]