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Purpose To focus on technical aspects of the implementation of interstitial high dose rate brachytherapy, with a step-by-step approach. Materials and methods Patients were selected during multidisciplinary tumor boards, according to inclusion criteria adapted from GEC-ESTRO guidelines. A CT scan was performed a few days before implantation. On pre-implant CT, using surgical scar and clips, surgical and pathological reports, and preoperative images, we delineated the tumor bed to be included in the Clinical Target Volume (CTV), according to GEC ESTRO Recommendations. A 3D virtual implant simulation of the best catheter positions was performed in order to cover the target volume. Implantation was then carried out under local anaesthetic using 3D projections of the catheter inlets and outlets. Dosimetry was performed on post-implantation CT scan. A dose of 34 Gy was delivered in 10 fractions. Acute and late side effects, and local control were evaluated 2 and 8 months after treatment. Results Between July 2017 and January 2020, 20 patients were treated with accelerated partial breast irradiation. Dose constraints regarding target volume coverage, overdose, dose homogeneity, conformation index and organs at risk were met in 94.7%, 100%, 63.2%, 0% and 89.5% of the treatment plans, respectively. Grade 1-2 acute adverse events were observed in 21% of patients, with no grade 3-4 events. Conclusion The first dosimetric results and early clinical tolerance and efficacy achieved by the implementation of breast interstitial multicatheter brachytherapy in routine clinical practice are very encouraging, and confirm the interest of extending this practice.

Purpose: A meta-analysis is presented comparing clinical outcomes and toxicities between high dose rate (HDR) and pulsed dose rate (PDR) brachytherapy (BT) for anal cancer. Methods and material: Retrospective or prospective clinical trials were identified on electronical databases. Data were collected per Preferred Reporting Items for Systematic Reviews and meta-Analyses guidelines. Pooled effect size for HDR and PDR BT were compared using subgroup analyses. Results: Nine retrospective studies with a total of 481 patients treated were included of which 219 with HDR and 262 with PDR. Significant differences were observed between the two groups for baseline characteristics and treatment. The cumulative proportion of stage T3-T4 was lower in the HDR group, 0.15 [95 % confidence interval (CI) 0.07–0.29] vs 0.27 [95 %CI 0.09–0.57] in the LDR group, p < 0.001. Lower BT doses (in equivalent 2-Gy fraction dose) were given for patients in the HDR group, 11.9 Gy [95 %CI 8.2–15.5] vs 19.5 Gy [95 %CI 15.0–24.0] in the PDR group, p < 0.001. No significant differences were found for clinical outcomes or toxicities. The pooled effect size of the overall survival at 5 years for HDR and PDR was respectively 0.82 [95 %CI 0.70–0.94] and 0.82 [95 %CI 0.73–0.91], p > 0.99. The 5 years local control was 0.86 [95 % confidence interval (CI) 0.81–0.91] and 0.83 [95 %CI 0.77–0.89], p = 0.62. Cumulative toxicity-related colostomy proportion was 0.04 [95 %CI 0.02–0.09] and 0.03 [95 %CI 0.02–0.07], p = 0.85. Conclusion: Both modalities provided a good profile of tolerance and are effective organ conservative strategies for patients with anal canal cancer. In parallel with ongoing developments to better determine the optimal fractionation and dose for HDR-BT treatments, especially in large tumors, PDR BT still has a crucial role for dose escalation strategy in advanced cases.

Summary Objective Radiotherapy remains an essential part of the management of locally advanced cervical cancer. Post-treatment surveillance allows for tumor response assessment and early detection of progressive prosecutions or local recurrences that may benefit from salvage treatment. The objective of this work is to assess the effectiveness of this therapeutic modality. Materials methods This is a retrospective study of 69 patients treated with concomitant radiation chemotherapy followed by high dose rate intracavitary brachytherapy. The tumor response was assessed by gynecologic physical examination at three months after the end of treatment. Results Median age of patients is 54.9 years (33–78 years). The most common histological type is squamous cell carcinoma (89.9%). The average dose received during external radiotherapy is 52.2 Gy (46–60 Gy). The average dose received during brachytherapy is 27.5 Gy (18–28 Gy). Three months after completion of treatment, 95.6% of patients had complete tumor remission, and only 4.4% had a tumor residue of 1 cm. Conclusion Radiation chemotherapy with brachytherapy allows for improved short-term local control in cervical cancer.

Purpose A prospective phase 2 study was conducted to evaluate the feasibility and safety of single-application multifractionated (SA-MF), high-dose-rate (HDR), image guided adaptive brachytherapy (IGABT) for cervical cancer. Methods and Materials Patients (N = 41) with International Federation of Gynaecology and Obstetrics 2009 stage IIB-IVA disease recruited between 2017 and 2019 underwent SA-MF. After completion of external beam radiation therapy of 50 Gy in 25 fractions, patients received magnetic resonance IGABT. The IGABT protocol consisted of a single brachytherapy (BT) application and treatment with 3 fractions of HDR (9 Gy on day 1; 2 fractions of 7 Gy with a minimum 6-hour gap on day 2) after achieving planning aims of the high-risk clinical target volume (HRCTV) receiving >84 Gy EQD2 and 2 cm3 of the bladder and rectum/sigmoid receiving ≤85 Gy and Results Thirty-eight patients were treated as per the protocol. All patients underwent Intracavitary + Interstitial BT with needles (median, 4; range, 3-11). The mean ± standard deviation HRCTV volume was 41 ± 21 cm3 and HRCTV D90 dose was 87.2 ± 3.6Gy. The 0.1 cm3 and 2 cm3 to bladder, rectum, and sigmoid were –103.2 ± 10.6 Gy and –84.6 ± 6.8 Gy, 82.2 ± 9.5 Gy and –68.3 ± 5.7 Gy, and 83.5 ± 9.8 Gy and –69.5 ± 5.9 Gy, respectively. Six patients required reoptimization before the second fraction to meet planning aims. Mean overall treatment time was 47 ± 6 days. With a median follow up of 22 months (range, 2-37), 2-year local control and disease-free and overall survival were 90.1%, 85%, and 94.5%, respectively. So far 1 patient with grade II and 2 patients with grade III rectal toxicities have been reported. Conclusion Magnetic resonance IGABT with SA-MF BT was feasible in 95% of patients. The dosimetric parameters and clinical results achieved so far look promising.

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

purpose This practice parameter aims to detail the processes, qualifications of personnel, patient selection, equipment, patient and personnel safety, documentation, and quality control and improvement necessary for an HDR brachytherapy program. Methods and Materials This practice parameter was revised collaboratively by the American College of Radiology (ACR), the American Brachytherapy Society (ABS), and the American Society for Radiation Oncology (ASTRO). Results Brachytherapy is a radiotherapeutic modality in which radionuclide or electronic sources are used to deliver a radiation dose at a distance of up to a few centimeters by surface, intracavitary, intraluminal, or interstitial application. Brachytherapy alone or combined with external beam radiotherapy plays an important role in the management and treatment of patients with cancer. High-dose-rate (HDR) brachytherapy uses radionuclides, such as iridium-192, at dose rates of ≥12 Gy/hr to a designated target point or volume, and it is an important treatment for a variety of malignant and benign conditions. Its use allows for application of high doses of radiation to defined target volumes with relative sparing of adjacent critical structures. Conclusions HDR brachytherapy requires detailed attention to personnel, equipment, patient and personnel safety, and continuing staff education. Coordination between the radiation oncologist and treatment planning staff and effective quality assurance procedures are important components of successful HDR brachytherapy programs.

This study aims to evaluate the efficacy, feasibility, tolerability, and toxicity of concurrent chemotherapy and brachytherapy for locally advanced cervical carcinoma.Forty patients of cervical carcinoma were included in this study. The study period ranges from October 2016 to September 2019. Patients were evaluated and treated as per the protocol: external beam radiotherapy (50 Gy in 25 fractions) and concurrent weekly chemotherapy with injection (Inj.) cisplatin (30 mg/mOut of 40 patients enrolled in the study, 36 patients completed the treatment (17 Stage II and 19 Stage III). The incidence of Grade I and II skin toxicities were 78% and 10%, respectively. The incidence of genitourinary toxicities with respect to Grade I and II were 72% and 12%, respectively. There were Grade III hematological toxicities in two patients and the brachytherapy treatment was delayed for 4-6 days. The overall complete response was found in 28 (78%) patients, partial response in six (16.7%) patients, and progressive disease in two (5.6%) patients at 3 months of follow-up. On the last follow-up, 21 (58%) patients were disease-free and there was disease failure in seven patients (5 local recurrence and 2 with distant metastasis).Brachytherapy with the addition of concurrent chemotherapy is effective and feasible with acceptable toxicity for advanced stages of carcinoma cervix. This study upholds an interesting approach that can be regarded as feasible and tolerable for cervical cancer patients.

BACKGROUND AND PURPOSE To analyse the cumulative incidence of any failure (AF), prostate cancer-specific failure (PCSF), any death (AD), prostate cancer-specific death (PCSD), and local control in 2387 men with prostate cancer (PC), consecutively treated with combined high-dose-rate brachytherapy (HDRBT) and external beam radiotherapy (EBRT) from 1998 to 2010. MATERIAL AND METHODS A retrospective, single-institution study of men with localised PC. The mean age was 66 years and 54.7% had high-risk PC according to the Cambridge prognostic group (CPG) classification. The treatment was delivered as EBRT (2 Gy × 25) and HDRBT (10 Gy × 2) with combined androgen blockade (CAB). The median follow-up was 10.2 years. RESULTS The cumulative incidence of PCSD at 10 years was 5% [CI 95% 0.04-0.06]. The 10 years PCSD per risk group were: low (L) 0.4%, intermediate favourable (IF) 1%, intermediate unfavourable (IU) 4.3%, high-risk favourable (HF) 5.8%, and high-risk unfavourable (HU) 13.9%. The PCSF rate at 10 years was 16.5% [CI 95% 0.15-0.18]. The PCSF per risk group at 10 years were: L 2.5%, IF 5.5%, IU 15.9%, HF 15.6%, and HU 38.99%. PCSF occurred in 399 men, of whom 15% were found to have local failure. The estimated frequency of local failure in the entire cohort was 1.2%. CONCLUSIONS HDRBT combined with EBRT is an effective treatment with long-term overall survival and excellent local control for patients with PC. The low rate of local recurrence among men with relapse suggests that these patients were micro metastasised at time of treatment, which calls for improved methods to detect disseminated disease.

Purpose Partial aponeurectomy (PA) is a standard procedure for Dupuytren's contracture (DC). Here we report a novel approach using surgery combined with perioperative high dose rate (192Ir-HDR) brachytherapy. Methods and patients From March 2018 until February 2020, thirteen rays of 6 patients with Dupyutren's contractures underwent PA followed by HDR brachytherapy. After removal of fibrous tissue and mobilization of the tendons, one to three catheters per patient were placed intraoperatively. Immediately after surgery, a planning computer tomography with 3D-planning was performed. Then 10-12 Gy were given to 0-2 mm from the catheters' surface and the catheters were removed 6-12 h after brachytherapy. Results No complications were observed. The mean contractures were reduced from 55.4° (standard error SE 19.6) to 15.4° (SE 6.7; p Conclusions HDR brachytherapy in combination with surgery is feasible and harbors the potential for combined modality therapy to reduce relapse rates of advanced or relapsing DC. Controlled studies are warranted to investigate the role of bimodal therapy compared with PA alone.

Highlights • Biochemical failure rates after focal salvage high-dose-rate brachytherapy are high. • Evidence on predictors for failure is limited to whole-gland salvage radiotherapy. • Two prediction models for biochemical failure were developed and internally validated. • Based on pre- and post-salvage characteristics we can identify high-risk patients. • These models can be used for patient counselling at baseline and during follow-up., Background and purpose Magnetic resonance-guided focal salvage high-dose-rate brachytherapy (FS-HDR-BT) for radiorecurrent prostate cancer (PCa) shows low toxicity rates. However, biochemical failure (BF) after treatment occurs frequently. We developed two prediction models for BF (Phoenix definition) with the aim of enhancing patient counselling before FS-HDR-BT and during follow-up. Materials and methods A prospective cohort of 150 radiorecurrent PCa patients treated with FS-HDR-BT between 2013 and 2020 was used for model development and internal validation. Multivariable Cox Proportional Hazards regression was applied. For model 1, only pre-salvage variables were included as candidate predictors. For model 2, additional (post-)salvage characteristics were tested. After calibration, nomograms and webtools were constructed. Finally, three risk groups were identified. Results Sixty-one patients (41%) experienced BF. At baseline (model 1), age, gross tumour volume, pre-salvage PSA, and pre-salvage PSA doubling time (PSADT) were predictive of BF. During follow-up (model 2), age, pre-salvage PSA and PSADT, seminal vesicle involvement, post-salvage time to PSA nadir, and percentage PSA reduction were predictive of BF. The adjusted C-statistics were 0.73 (95% CI: 0.66–0.81) and 0.84 (95% CI: 0.78–0.90), respectively, with acceptable calibration. Estimated 2-year biochemical disease-free survival for the low-, intermediate-, and high-risk groups were 84%, 70%, and 31% (model 1), and 100%, 71%, and 5% (model 2). Conclusion Two models are provided for prediction of BF in patients with radiorecurrent PCa treated with FS-HDR-BT. Based on pre- and post-salvage characteristics, we are able to identify patients with a high risk of BF. These findings can aid patient counselling for FS-HDR-BT.

Author(s): Kunogi, Hiroaki; Hsu, I-Chow; Sasai, Keisuke | Abstract: PurposeBulky chest wall recurrence after mastectomy presents a therapeutic challenge because of high-dose of radiation required to control the disease, and its proximity to low-tolerance organs at risk. We report a case of successful computed tomography (CT)-guided high-dose-rate (HDR) salvage interstitial brachytherapy (ISBT) boost.Material and methodsA 70-year-old female initially presented with a tumor in right breast, and was treated with mastectomy and adjuvant chemotherapy, followed by hormonal therapy for 5 years without adjuvant radiotherapy. In 2018, 20 years after the initial treatment, she developed unresectable chest wall recurrence that measured 10.5 cm × 7.3 cm × 4.5 cm, with bone and parietal pleura invasion. Biopsy revealed invasive pleomorphic lobular carcinoma [estrogen receptor (ER)-positive, progesterone receptor (PR)-negative, HER2-negative]. There was no evidence of metastatic disease.ResultsThe patient underwent external beam radiotherapy (EBRT) plus ISBT. After EBRT of 50 Gy in 25 fractions was completed, CT-guided ISBT was performed as an outpatient treatment. HDR dose was 16 Gy delivered in 2 fractions with 2 implants. Dose was prescribed to gross tumor volume. ISBT plans were created using inverse planning simulated annealing (IPSA) algorithm. Gross tumor volume D90% plus EBRT dose was 82 Gy equivalent dose of 2 Gy (EQD2), assuming α/β of 4 for breast carcinoma. The patient continued on hormonal therapy. At the 30-month follow-up, the patient remains in remission. The tumor could not be detected by magnetic resonance imaging (MRI) or positron emission tomography (PET). There were no severe treatment-related complications.ConclusionsCT-guided HDR ISBT boost can be a useful modality in individualizing treatment strategies for breast cancer patients with unresectable bulky chest wall recurrence.

Purpose Radiotherapy with high-dose-rate (HDR) brachytherapy is used to treat nonmelanoma skin cancers. We retrospectively analyzed a hypofractionated regimen to assess its safety and efficacy in elderly patients ≥70 years. Methods and Materials Forty-eight patients with 67 lesions treated since 2016 with catheter-based iridium-192 HDR brachytherapy using a custom mold or three-dimensional–printed applicator met inclusion criteria. Treatment was 36 Gy in six weekly fractions. Local and locoregional control were assessed with Kaplan–Meier curves. Acute and late toxicity were graded as per Common Terminology Criteria for Adverse Events, version 5. Cosmesis was defined as “excellent” (indistinguishable from untreated skin), “good” (minimal changes), or “poor” (extensive changes). Univariate analyses were performed. Results Median age was 85.7 years, and 21 were female. Durable local control occurred in 63 lesions (94.0%), giving estimated local control of 100% at 6 months, 95.1% at 1 year, and 88.8% at 2 years. No factors were predictive of local control on univariate analysis. All experienced acute toxicity that ultimately resolved: 28.4% Grade 2 and 4.5% Grade 3. Larger treatment volume receiving ≥36 Gy was associated with increased Grade ≥2 acute toxicity. Patients experienced late Grade 2 and late Grade 4 toxicity after 6.5% treatments each. Younger age was associated with increased Grade ≥2 late toxicity. “Good” or better cosmesis occurred in 93.2%, and “poor” cosmesis was associated with lower extremities and larger lesions. Conclusions Hypofractionated HDR brachytherapy using 36 Gy in six weekly fractions is associated with satisfactory locoregional control and cosmesis with minimal risk of severe acute or late toxicities.

Purpose To perform a propensity-score matched analysis comparing stereotactic body radiation therapy (SBRT) boost and high-dose-rate (HDR) boost for localized prostate cancer. Methods and Materials A single-institution retrospective chart review was conducted of men treated with pelvic external beam radiation therapy (EBRT) and SBRT boost (21 Gy and 19 Gy in 2 fractions) to the prostate for prostate cancer. A cohort treated at the same institution with HDR brachytherapy boost (19 Gy in 2 fractions) was compared. Propensity-score (PS) matching and multivariable Cox regression were used for analysis. Outcomes were biochemical recurrence freedom (BCRF) and metastasis freedom (MF). Results One hundred thirty-one men were treated with SBRT boost and 101 with HDR boost with median follow-up of 73.4 and 186.0 months, respectively. In addition, 68.8% of men had high-risk and 26.0% had unfavorable-intermediate disease, and 94.3% received androgen deprivation therapy. Five- and 10-year unadjusted BCRF was 88.8% and 85.3% for SBRT and 91.8% and 74.6% for HDR boost (log-rank P = .3), and 5- and 10-year unadjusted MF was 91.7% and 84.3% for SBRT and 95.8% and 82.0% for HDR (log-rank P = .8). After adjusting for covariates, there was no statistically significant difference in BCRF (hazard ratio [HR] 0.81; 95% confidence interval [CI], 0.37-1.79; P = .6) or MF (HR 1.07; 95% CI, 0.44-2.57; P = .9) between SBRT and HDR boost. Similarly, after PS matching, there was no statistically significant difference between SBRT and HDR (BCRF: HR 0.66, 0.27-1.62, P = .4; MF: HR 0.84, 0.31-2.26, P = .7). Grade 3+ genitourinary and gastrointestinal toxicity in the SBRT cohort were 4.6% and 1.5%, and 3.0% and 0.0% in the HDR cohorts (P = .4, Fisher exact test). Conclusions SBRT boost plus pelvic EBRT for prostate cancer resulted in similar BCRF and MF to HDR boost in this single institution, PS matched retrospective analysis. Toxicity was modest. Prospective evaluation of SBRT boost for the treatment of unfavorable-intermediate and high-risk prostate cancer is warranted.

Aim The dominant intraprostatic lesion (DIL) is the commonest site of relapse after single dose high-dose-rate brachytherapy (HDR-BT) for localised prostate cancer. This study investigated toxicity and clinical outcomes of focal dose escalation to the DIL with dose de-escalation to the remaining prostate. Materials/Methods Between November 2012 and July 2016, 50 patients with localised prostate adenocarcinoma received single fraction HDR-BT. 21 Gy was prescribed to the DIL, with two de-escalation prescription schedules for the remaining prostate. Primary outcomes included biochemical no evidence of disease (bNED), local recurrence free survival (LRFS), and metastasis free survival (MFS). Secondary outcomes included late genitourinary, gastrointestinal and sexual toxicity. Kaplan—Meier analyses with log rank tests were used to estimate bNED, LRFS and MFS. Results With a median follow up of 70.6 months, 15 patients developed biochemical failure, including 8 in the group that received minor dose de-escalation to the non-DIL prostate (group 1) and 7 in the group that received moderate de-escalation (group 2). Five-year bNED was 88% in group 1 and 76% in group 2 (p = 0.05). Overall 4-year and 5-year FFLF in group 1 was 100% and 96% and in group 2 92% and 84%. These differences were statistically significant (p = 0.03). No acute ≥G3 genitourinary or ≥G2 gastrointestinal toxicity was reported. The median IIEF decreased in the first 6 months improving to a peak median score of 20 at 54 months. Conclusion Focal boost to the DIL did not improve biochemical or local control after single-fraction HDR monotherapy compared to what would be expected from 19 Gy single fraction treatment to the whole gland.

Background and purpose: Delineation of organs at risk (OARs), such as the bladder, rectum and sigmoid, plays an important role in the delivery of optimal absorbed dose to the target owing to the steep gradient in high-dose rate brachytherapy (HDR-BT). In this work, we propose a deep convolutional neural network-based approach for fast and reproducible auto-contouring of OARs in HDR-BT.Materials and methods: Images of 113 patients with locally-advanced cervical cancer were utilized in this study. We used ResU-Net deep convolutional neural network architecture, which uses long and short skip connections to improve the feature extraction procedure and the accuracy of segmentation. Seventythree patients chosen randomly were used for training, 10 patients for validation, and 30 patients for testing. Well established quantitative metrics, such as Dice similarity coefficient (DSC), Hausdorff distance (HD), and average symmetric surface distance (ASSD), were used for evaluation.Results: The DSC values for the test dataset were 95.7 +/- 3.7%, 96.6 +/- 1.5% and 92.2 +/- 3.3% for the bladder, rectum, and sigmoid, respectively. The HD values (mm) were 4.05 +/- 5.17, 1.96 +/- 2.19 and 3.15 +/- 2.03 for the bladder, rectum, and sigmoid, respectively. The ASSDs were 1.04 +/- 0.97, 0.45 +/- 0.09 and 0.79 +/- 0.25 for the bladder, rectum, and sigmoid, respectively.Conclusion: The proposed deep convolutional neural network model achieved a good agreement between the predicted and manually defined contours of OARs, thus improving the reproducibility of contouring in brachytherapy workflow. (c) 2021 Elsevier B.V. All rights reserved. Radiotherapy and Oncology 159 (2021) 231-240

Highlights • The optimal sequence of HDR-BT boost and EBRT for prostate cancer is unclear. • We compared early toxicity based on the timing of HDR-BT boost. • The timing of HDR-BT was not based on any specific patient or clinical factors. • We found no difference in early GI/GU toxicity between the two groups. • Longer follow-up is needed to evaluate late toxicity and long-term disease control., Background We present the first report comparing early toxicity outcomes with high-dose rate brachytherapy (HDR-BT) boost upfront versus intensity modulated RT (IMRT) upfront combined with androgen deprivation therapy (ADT) as definitive management for intermediate risk or higher prostate cancer. Methods and Materials We reviewed all non-metastatic prostate cancer patients who received HDR-BT boost from 2014 to 2019. HDR-BT boost was offered to patients with intermediate-risk disease or higher. ADT use and IMRT target volume was based on NCCN risk group. IMRT dose was typically 45 Gy in 25 fractions to the prostate and seminal vesicles ± pelvic lymph nodes. HDR-BT dose was 15 Gy in 1 fraction, delivered approximately 3 weeks before or after IMRT. The sequence was based on physician preference. Biochemical recurrence was defined per ASTRO definition. Gastrointestinal (GI) and Genitourinary (GU) toxicity was graded per CTCAE v5.0. Pearson Chi-squared test and Wilcoxon tests were used to compare toxicity rates. P-value

Purpose Using multiparametric MRI data and the pathologic data from radical prostatectomy specimens, we simulated the treatment planning of dose-escalated high-dose-rate brachytherapy (HDR-BT) to the Multiparametric MRI dominant intraprostatic lesion (mpMRI-DIL) to compare the dose potentially delivered to the pathologically confirmed locations of the high-grade component of the cancer. Methods and Materials Pathologist-annotated prostatectomy midgland histology sections from 12 patients were registered to preprostatectomy mpMRI scans that were interpreted by four radiologists. To simulate realistic HDR-BT, we registered each observer's mpMRI-DILs and corresponding histology to two transrectal ultrasound images of other HDR-BT patients with a 15-Gy whole-gland prescription. We used clinical inverse planning to escalate the mpMRI-DILs to 20.25 Gy. We compared the dose that the histopathology would have received if treated with standard treatment plans to the dose mpMRI-targeting would have achieved. The histopathology was grouped as high-grade cancer (any Gleason Grade 4 or 5) and low-grade cancer (only Gleason Grade 3). Results 212 mpMRI-targeted HDR-BT plans were analyzed. For high-grade histology, the mpMRI-targeted plans achieved significantly higher median [IQR] D98 and D90 values of 18.2 [16.7–19.5] Gy and 19.4 [17.8–20.9] Gy, respectively, in comparison with the standard plans (p = 0.01 and p = 0.003). For low-grade histology, the targeted treatment plans would have resulted in a significantly higher median D90 of 17.0 [16.1–18.4] Gy in comparison with standard plans (p = 0.015); the median D98 was not significantly higher (p = 0.2). Conclusions In this retrospective pilot study of 12 patients, mpMRI-based dose escalation led to increased dose to high-grade, but not low-grade, cancer. In our data set, different observers and mpMRI sequences had no substantial effect on dose to histologic cancer.

Purpose 3D printing has become a popular and widely available technique of rapid prototyping. The impact of used materials on the dose distribution has been studied for high energy sources. However, brachytherapy sources emit lower energy photons, and materials used in 3D printing may differ. This study was conducted to analyze the influence of common materials (polylactic acid – PLA and acrylonitrile butadiene styrene – ABS) used in stereolithography. Material and methods A 3D-printed phantom was designed, printed, and used to calibrate Gafchromic films. In the next step, a range of 1 mm thick plates of PLA and ABS (from zero to thirty) were inserted between source and detector to measure the impact of studied materials on delivered dose. Measurements were performed using a calibrated radiochromic film and Farmer ionization chamber in water. Results No statistically significant correlation (p = 0.4854) between the thickness of inserted PLA and the dose delivered to the film was obtained. With ionization chamber, Spearman’s rank order test showed a significant correlation (p = 0.00004); however, the correlation was found weak. In case of ABS measurement, a statistically significant (p = 0.0159), yet weak negative correlation was found between the thickness of used material and the dose delivered to the film. On the other hand, a weak statistically significant (p = 0.0212) but positive correlation was found when the dose was measured with Farmer ionization chamber. We find these correlations false, as all measured doses were within the measurement uncertainty range (film ±8.0%, Farmer ±8.8%) from 100% of the prescribed dose. Conclusions According to obtained results, with the accuracy of measurement under clinical conditions, the impact of highly filled PLA and ABS printed objects on the dose distribution from an 192Ir source in water can be omitted.

Purpose/objective Long-term follow up of single dose high-dose rate brachytherapy (HDR BT) for localised prostate cancer has revealed higher than expected rates of biochemical and local failure. This study aimed (i) to investigate the pattern of relapse within the prostate with reference to the initial site of disease in those patients; and (ii) to examine if there were any relationships between the HDR BT dosimetric parameters to these areas of recurrence. Materials/methods A retrospective review of treatment records of patients who received 19 Gy single fraction of HDR BT was carried out. A matched pair analysis used one control for each biochemical recurrence case matched with pre-treatment Clinical target volume (CTV) size, Gleason score, T stage, risk category and presence of an identifiable dominant intraprostatic nodule (DIL) for each biochemical recurrence case identified. For all datasets, the pre HDR BT DILs were delineated on the diagnostic pre-treatment T2-weighted MRI and planning CT images. For patients with local recurrence post HDR BT, the recurrent nodules were contoured on the diagnostic T2-weighted MRI and choline PET which were registered to the original HDR BT planning CT. Dosimetric parameters of CTV, planning target volume (PTV), DIL and organs at risk (OARs) were evaluated. Wilcoxon signed-rank test was performed to investigate if there were any significant differences in dosimetric parameters between cases and controls. Cox regression analysis was performed to explore if there were any clinical and dosimetric parameters predicting for biochemical progression free survival (bPFS), local recurrence free survival (LR-PFS) and DIL recurrence free survival (DIL-PFS). Results Between 2013 and 2018, 180 patients received 19 Gy HDR-BT monotherapy. With a median follow up of 36 months, 19 (10.6%) patients developed biochemical recurrence. Of the 19 patients with biochemical failure, 13 had a local recurrence, including 7 who occurred at the site of DIL. Thirty-eight intermediate/high risk patients were included in the matched pair analysis. No statistically significant differences were found in all CTV, PTV, DIL and OAR dosimetric parameters between cases and controls (p > 0.05). For the Cox regression analysis, none of the covariates investigated were found to be statistically significant factors to predict for bPFS, LC-PFS and DIL-PFS. Conclusion No associations between biochemical recurrences and HDR BT dosimetry were identified in our cohort of patients receiving 19 Gy single fraction HDR BT. A large proportion of recurrences occurred at the site of original disease. HDR BT for intermediate/high risk prostate cancer should be undertaken using a minimum of two fractions.

Purpose To compare brachytherapy (BT) boost of low-dose-rate (LDR) and high-dose-rate (HDR) techniques in patients diagnosed with intermediate-risk prostate cancer. Material and methods Between January 2005 and February 2018, 142 patients (50 LDR and 92 HDR) with intermediate-risk prostate cancer were treated with a BT boost, and retrospectively analyzed. Prescribed dose was 45 Gy with external beam radiotherapy (EBRT) plus 100-108 Gy with LDR-BT, and 60 Gy with EBRT plus one fraction of 10 Gy with HDR-BT. 99% of patients received androgen deprivation therapy (ADT) for 6 months. Primary endpoint was to compare LDR and HDR boosts in terms of biochemical progression-free survival (bPFS). Secondary endpoint, after re-classifying patients into "favorable" and "unfavorable" sub-groups, was to analyze differences with a similar treatment intensity. Results Median overall follow-up for the total cohort was 66.5 months (range, 16-185 months). There were no significant differences in bPFS, overall survival, cause specific survival, local failure, lymph node failure, or distant failure when LDR or HDR was employed. bPFS at 90 months was 100% for favorable, and 89% and 85% for unfavorable patients at 60 months and 90 months, respectively (log-rank test, p = 0.017). The crude incidence of genitourinary acute and chronic toxicity grade 3 was 0.7% and 4%, respectively. Twelve patients (8%) had chronic rectal hemorrhage grade 2, in whom argon was applied (4 LDR and 8 HDR). Conclusions Combined treatment is an excellent therapeutic option in patients with intermediate-risk prostate carcinoma, with similar results in both LDR and HDR approaches and very low toxicities. Importantly, the current literature has indicated that unfavorable-risk patients belong to a different category, and should be treated as patients with high-risk factors. Therefore, the stratification and identification of both risk groups is extremely relevant.

This study compares the plan quality of high-dose-rate brachytherapy (HDR-BT) and volumetric modulated arc therapy (VMAT) for superficial irradiation of large areas of skin with significant curvature in one or more planes. A total of 14 patients from two centres previously treated with either HDR-BT or VMAT were retrospectively replanned using the alternative technique. Sites included scalp and lower limbs. Identical computed tomography (CT) scans, clinical target volume (CTV) and organs at risk (OARs) and prescription were used for both techniques. Conformity, skin surface dose and OAR doses were compared. Conformity index was consistently better with VMAT than HDR-BT (p

Purpose Multiple dwell positions (“multidwell”) within a Leipzig-style applicator can be used to increase dose uniformity and treatment area. Model-based dose calculation algorithms (MBDCAs) are necessary for accurate calculations involving these applicators because of their nonwater equivalency and complex geometry. The purpose of this work was to create template plans from MBDCA calculations and present their dwell times and positions for users of these applicators without access to MBDCAs. Methods and Materials The Leipzig-style solid applicator model within our treatment planning system was used to design template plans. Five template plans, normalized to 0.3 cm depth within a water phantom, were optimized using the treatment planning system MBDCA. Each template plan contained unique dwell positions, times, and active lengths (0.5–1.5 cm). A single-dwell distribution was optimized for comparison. The stem of this applicator stops within the shell; therefore, one template plan contained an intrafraction rotation to determine the largest dose distribution achievable. Effects of imperfect applicator rotation were quantified by inserting rotational offsets and comparing the V100%, D95%, and minimum dose coverage for planning target volumes created from 80%/90% isodose lines. Results The 90% (80%) isodose line dimensions at 0.3 cm depth for single-dwell increased from 0.94 × 0.97 (1.53 × 1.57) cm2 to 2.09 × 1.24 (2.75 × 1.88) cm2 in the largest template plan. Manually inserted angular offsets up to ±10° for the template plan requiring rotation preserved V100%, D95%, and minimum dose within 2.0%, 1.9%, and 8.0%, respectively. Conclusion A set of template plans was created to provide accessibility to the multidwell methodology, even for users without access to MBDCAs. Each template plan should be reviewed before clinical implementation.

Highlights • Severe toxicity is as low as 3% (GU), 0% (GI) and 15% (ED). • Lower impact is predicted for patients with favorable function at baseline. • Lower dose to the urethra (D10%, Background and purpose Local re-treatment of radiorecurrent prostate cancer is potentially curative. However, the increased risk of severe toxicity may outweigh the opportunity of cancer control. This study aims to evaluate treatment-related toxicity from ultrafocal salvage high-dose-rate brachytherapy (HDR-BT) and to investigate potential risk factors. Materials and methods Toxicity data from 150 treated patients (July 2013–November 2019) was collected from a prospective registry. The treatment aim was to deliver a single dose of 19 Gy to the recurrent lesion as identified on multiparametric MRI and PET-CT. Treating physicians graded genitourinary (GU) and gastro-intestinal (GI) toxicity and erectile dysfunction (ED) using the Common Terminology Criteria for Adverse Events (CTCAE) 4.0, at baseline and during follow-up. Domains with substantial (≥10%) new-onset grade ≥ 2 toxicity were further evaluated using mixed effects logistic regression to find potential risk factors. Results Median follow-up time was 20 months (IQR 12–31). Over time, new-onset grade 2 and 3 toxicity was recorded in 41% and 3% (GU), 5% and 0% (GI) and 22% and 15% (ED). While GI toxicity remained stably low, grade ≥ 2 GU toxicity and ED were seen twice as frequent in the late phase (>3 months after treatment). Significant risk factors for grade ≥ 2 toxicity were baseline GU toxicity (grade ≥ 2), baseline ED (grade ≥ 2), IPSS (cut-off ≥ 14) and urethral dose (D10%, cut-off ≥ 17 Gy). Conclusion Ultrafocal salvage HDR-BT is a safe re-treatment option, especially in patients with a favorable symptom profile at baseline. Adherence to urethral dose constraints is important to avoid GU toxicity.

Background . Prostate cancer (PCa) is one of the most common malignant diseases in men worldwide, with over 1.1 million cases of PCa reported annually. In the Russian Federation, the proportion of patients with stage I—II PCa from 2008 to 2018 increased from 37.6 % to 56 %, which in turn allows more and more patients to perform radical treatment methods. However, it should be noted that the number of patients with both recurrent PCa after radiation therapy (external beam radiation therapy (EBRT) or brachytherapy) and with local recurrence after radical prostatectomy (RPE) is steadily increasing. Objective . Improve treatment outcomes for patients with recurrent PCa. Materials and methods. A. F. Tsyb Medical Radiological Research Center — branch of the National Medical Research Radiological Center, since 2016, has been treating patients with recurrent PCa using salvage high-dose brachytherapy (SHDR) (192Ir) after radical radiation treatment (EBRT, brachytherapy) or with local recurrence after RPE. Patients with recurrent PCa were divided into three groups, depending on the type of initial radical treatment: patients with recurrent disease after RPE, after EBRT and after brachytherapy. Results . The most favorable results of SHDR were registered in the group of patients with local recurrence after RPE: in 7 patients out of 8 (87 %), one year after the PSA, the prostate-specific antigen (PSA) level was less than 0.1 ng/mL. In 1 patient, the PSA level dropped to 0.71 ng/mL (baseline 2.47 ng/mL) two years after salvage treatment. Currently, there is a further decrease in PSA levels. Results after SHDR ( 192 Ir) in patients with relapse after EBRT: of 8 patients, 2 (25 %) had PSA levels less than 0.2 ng/mL after a year. In 4 patients, the PSA level two years after treatment was more than 2.0 ng/mL. In these patients, a relapse was registered. Another 2 patients also had a repeated relapse after SHDR. The following results were obtained after carrying out SHDR in patients with relapse after braahythempy (both low- and high-dose). Of the 12patients, 7patients (58 %) had PSA levels less than 0.5 ng/mL two years after SHDR. SHDR was performed in the mode of two fractions of 12.5 Gyerahwith an interval of two weeks between them. In 3 patients, the PSA level exceeded 0.5 ng/ mL two years after the salvage treatment, and therefore, a second relapse is determined in them. Another 2 patients also had a repeated relapse. Conclusion . This article provides preliminary results of our research. We would like to reiterate that as possible options for the treatment of local recurrence of PCa, it is possible to choose salvage prostatectomy, salvage radiation therapy, hormonal therapy or SHDR brachytherapy. In some cases EBRT is used in this category of patients, however, this can lead to the development of severe radiation damage. The choice of a treatment method in case of recurrent PCa is a complex problem, the decision of which is based on many factors. The clinical course of PCa, the prevalence of the disease, the level of markers, and molecular genetic data are taken into account.

ObjectiveThe majority of patients with cervical cancer in Ghana present with locally advanced disease. In October 2014, high-dose rate (HDR) brachytherapy was introduced at the National Center for Radiotherapy, Accra after years of using low-dose rate (LDR) brachytherapy. The aim of this study was to compare the treatment outcomes of patients treated with LDR versus HDR brachytherapy.MethodsPatients with cervical cancer treated from January 2008 to December 2017 were reviewed. Those with stage IB–IIIB who received chemoradiation plus brachytherapy were included in the study. Post-operative patients and those with stage IV were excluded. The study end points were local control, disease-free survival, and overall survival at 2 years. Endpoints were estimated using the Kaplan–Meier method. Comparisons between treatment groups were performed using the log-rank test and Cox proportional hazards model.ResultsWe included 284 LDR and 136 HDR brachytherapy patients. For stages IB, IIA, IIB, IIIA and IIIB disease, the 2-year local control for LDR versus HDR brachytherapy was 63% and 61% (p=0.35), 86% and 90% (p=0.68), 86% and 88% (p=0.83), 66% and 60% (p=0.56), and 77% and 40% (p=0.005), respectively. The 2-year disease-free survival for LDR versus HDR brachytherapy was 64% and 61% (p=0.50), 81% and 69% (p=0.18), 81% and 80% (p=0.54), 62% and 33% (p=0.82), and 71% and 30% (p=0.001) for stages IB, IIA, IIB, IIIA, and IIIB, respectively. The 2-year overall survival for LDR versus HDR brachytherapy was 94% and 93% (p=0.92), 98% and 68% (p=0.21), 89% and 88% (p=0.60), and 88% and 82% (p=0.34) for stages IB, IIA, IIB, and IIIB disease, respectively.ConclusionThere was no difference between LDR and HDR brachytherapy in local control and disease-free survival for all stages of disease, except in stage IIIB. These findings highlight the need to refine this brachytherapy technique for this group of patients.

Purpose The purpose of this investigation was to examine differences in estimates of accumulated rectal dose when using deformable image registration (DIR) compared with rigid image registration (RIR) methods, and parameter addition methods for combined transrectal ultrasound (TRUS)-based high-dose-rate brachytherapy (HDR-BT) and external beam radiation therapy (EBRT) treatments of prostate cancer. Material and methods In this retrospective study, data from 10 patients who had previously received HDR-BT in one 15 Gy fraction, followed by 46 Gy EBRT in twenty-three fractions were used. To estimate total combined dose to the rectum, dose accumulation using both DIR and RIR methods were compared with parameter addition methods, which assume the same region of rectal anatomy receives the maximum dose from both treatment modalities. For both rigid and deformable image registration techniques, the quality of image registration was evaluated through metrics, including mean distance to agreement and dice similarity coefficient of prostate contours. Total D1cc and D2cc for the rectum was calculated and compared using each method. Results The parameter addition methods predicted the highest accumulated dose to the rectum. On average, the predicted D2cc dose was higher than that calculated by the DIR method by 6.59 Gy EQD2 (range, -3.03 to 13.68 Gy EQD2) for partial parameter addition (PPA), and 4.88 Gy EQD2 (range, -3.41 to 11.97 Gy EQD2) for the full parameter addition (FPA) methods. Similarly, RIR predicted higher average doses compared with DIR, with a difference of 3.46 Gy EQD2 (range, -5.50 to 7.90 Gy EQD2). The results showed a significant difference between DIR and parameter addition methods for dose estimation. Conclusions This retrospective study demonstrates significant differences in accumulated rectal dose prediction using different image registration methods. Each method has limitations in its application, and when used with real-time HDR-BT dose planning, awareness of these limitations is essential.

Purpose This study investigated the suitability of brachytherapy technique selection based on pre-brachytherapy magnetic resonance imaging (MRI) findings in cervical cancer by evaluating dose-volume histogram parameters. Material and methods We retrospectively evaluated data from 61 patients with cervical cancer who underwent pre-brachytherapy MRI within 7 days before their first high-dose-rate brachytherapy treatment, selected according to pre-brachytherapy MRI findings. Combined intracavitary brachytherapy with interstitial techniques (IC/ISBT) or interstitial brachytherapy (ISBT) were favored treatments for poor-responding tumors after concurrent chemoradiotherapy, asymmetrical tumors, bulky parametrial extensions, bulky primary disease, and extensive paravaginal or distal vaginal involvement. Intracavitary brachytherapy (ICBT) was the preferred treatment for small tumors without extensive involvement of the vagina and parametrium. Results The median tumor size was 58 mm on pre-treatment MRI and 38 mm on pre-brachytherapy MRI. On pre-brachytherapy MRI, 13 patients had a tumor with severe vaginal invasion, 15 patients presented with an asymmetrical bulky tumor, and 4 patients had bulky residual tumors. IC/ISBT or ISBT were administered to 26 patients (43%). Median equivalent dose in 2 Gy fractions of clinical target volume D90 was 70.8 Gy for all patients. Median clinical target volume D90 in each brachytherapy session exceeded the prescribed dose in both patients treated with ICBT and IC/ISBT or ISBT. Median equivalent dose in 2 Gy fractions of D2cc to the bladder, sigmoid colon, and rectum was 69.5, 52.0, and 58.4 Gy, respectively. All cases remained within the doses recommended for organs at risk. Conclusions Pre-brachytherapy MRI may be helpful in selecting suitable candidates for each type of brachytherapy and deliver the recommended doses to the tumor and organs at risk, particularly in cases with large tumors, poor response to concurrent chemoradiotherapy, asymmetrical tumors, severe vaginal invasion, extensive parametrial invasion, and/or corpus invasion.

Purpose To evaluate toxicity, prostate-specific antigen (PSA) kinetics, and cancer control of high-dose-rate brachytherapy (HDR-BT) as a salvage modality for men with locally recurrent prostate cancer, after primary HDR-BT failure. Material and methods Twelve patients with biochemical failure and a local relapse after 19 Gy single-fraction high-dose-rate brachytherapy (HDR-BT 19 Gy) were salvaged using two HDR-BT fractions. Salvage treatment consisted of two HDR-BT applications, one week apart, delivering 12 Gy to the prostate per application (HDR-BT 12 × 2). Results Median age and initial PSA prior to rescue treatment were 74 years (range, 65-80) and 5.29 ng/ml (range, 2.37-16.40), respectively. Forty-two percent had a low-risk and 58% presented with intermediate-risk prostate cancer. Median follow-up period was 26 months (range, 10-42). Median time to PSA nadir was 12 months, with a median value of 0.21 ng/ml. Most of the patients (11 of 12) achieved a PSA decline ≥ 90%. Acute grade 2 genitourinary (GU) toxicity occurred in 4 patients (33.3%) and none presented with acute gastrointestinal (GI) toxicity. Two patients (16.7%) suffered from late GU grade 2 toxicity. No grade 3 toxicity were recorded. To date, 2 patients (16.7%) have experienced biochemical failure after salvage treatment. Conclusions Salvage HDR-BT 12 × 2 is a feasible and well-tolerated treatment, with acceptable toxicity rates for men with locally recurrent prostate cancer, who failed after HDR-BT with 19 Gy. Moreover, PSA kinetics and cancer control after salvage treatment suggest that this strategy might be efficacious in this clinical setting.

Purpose The objective of this study was to examine feasibility of single- or hypo-fraction of high-dose-rate (HDR) electronic brachytherapy (eBT) in uveal melanoma treatment. Material and methods Biologically effective doses (BED) of organs at risk (OARs) were compared to those of iodine-125-based eye plaque low-dose-rate brachytherapy (125I LDR-BT) with vitreous replacement (VR). Single- or hypo-fractionated equivalent physical doses (SFEDs or HFEDs) for tumor were calculated from tumor BED of 125I LDR-BT using linear-quadratic (LQ) and universal survival curve (USC) models. BED OARs doses to retina opposite the implant, macula, optic disc, and lens were calculated and compared among SFED, HFED, and 125I LDR-BT. Electronic BT of 50 kVp was considered assuming dose fall-off as clinically equivalent to 125I LDR-BT. All OARs BEDs were analyzed with and without silicone oil VR. Results For a single-fraction incorporating VR, the median/interquartile range of LQ (USC)-based BED doses of the retina opposite the implant, macula, optic disc, and lens were 16%/1.2% (33%/4%), 35%/19.5% (64%/17.7%), 37%/19% (75%/17.8%), and 27%/7.9% (68%/23.2%) of those for 125I LDR-BT, respectively. SFED tumor values were 29.8/0.2 Gy and 51.7/0.5 Gy when using LQ and USC models, respectively, which could be delivered within 1 hour. SFED can be delivered within 1 hour using a high-dose-rate eBT. Even four-fraction delivery of HFED without VR resulted in higher OARs doses in the macula, optic disc, and lens (135 ~ 159%) than when using 125I LDR-BT technique. A maximum p-value of 0.005 was observed for these distributions. Conclusions The simulation of single-fraction eBT, including vitreous replacement, resulted in significantly reduced OARs doses (16 ~ 75%) of that achieved with 125I LDR-BT.

Purpose High-dose-rate (HDR) brachytherapy as primary therapy (monotherapy) is a standard National Comprehensive Cancer Network (NCCN) endorsed treatment option for patients with localized prostate cancer. Thus far, most data are limited to single-institution experiences. Accordingly, we sought to systematically review rates of biochemical recurrence-free survival (bRFS) and toxicity associated with fractionated HDR monotherapy. Material and methods A systematic review was performed using PubMed and Embase databases for relevant articles published between January 1999 and December 2019, according to preferred reporting items for systematic review and meta-analyses (PRISMA) guidelines. Included studies were limited to fractionated HDR monotherapy publications in full manuscript form with at least 5-year median follow-up, at least 80 patients included, and adequate reporting of bRFS and toxicity data. Meta-analyses were performed with random-effect modeling. Extent of heterogeneity between studies was determined using I 2 and Cochran's Q tests. Results Seven unique studies were identified, including 2,123 patients. NCCN low-, intermediate-, and high-risk patients comprised 40%, 40%, and 20% of patients, respectively. Median follow-up at the study group level was 74 months (range, 60-131 months). The 5-year bRFS rate was 95% (95% confidence interval [CI]: 93-96%), and after adjusting to control for publication bias, it was 96% (95% CI: 94-99%). Estimated adjusted late grade ≥ 3 genitourinary and gastrointestinal toxicity rates were 2% (95% CI: 1-4%) and 0.3% (95% CI: 0-1.1%), respectively. Conclusions Fractionated HDR monotherapy is associated with high rates of disease control and low rates of toxicity. Future studies are needed to better define the value of this treatment modality relative to other options.

A 28-year-old female with locally advanced adenocarcinoma of the cervix was undergoing treatment with external beam radiation therapy (EBRT), concurrent chemotherapy and high dose rate brachytherapy (BT). On-board imaging obtained prior to one of her external beam treatments revealed four radiopaque foreign bodies in her abdomen. The patient's treatment was delayed for further work-up of this new finding. Upon further investigation, it was discovered that the patient had recently started taking bismuth subsalicylate tablets (brand name: Pepto-Bismol, Procter & Gamble Co., Cincinnati, OH). A computed tomography (CT) scan of the tablets confirmed the size and Hounsfield Unit (HU) values coincided with the foreign object properties seen on the patient's scan. This unexpected finding is important to recognize as it consequently lead to a delay in treatment, additional imaging, and patient anxiety.

Purpose The purpose of the study was to describe our approach towards safe delivery of single-fraction high-dose-rate (HDR) brachytherapy (BT) boost in patients with prostate cancer in the setting of an unshielded operating room (OR). Methods and Materials A total of 95 patients received 15 Gy HDR BT boost. The procedure involved transrectal ultrasound–based catheter insertion and planning in the OR, after which the patient was moved to a shielded treatment room for radiation. This required three vital components: (1) an OR table capable of transporting the patient in lithotomy position, (2) robust motion management checks to ensure reproducibility of prostate and catheter positions in the treatment room before radiation delivery, (3) remote monitoring of patient vitals while under anesthesia, during the radiation. Initial viability of this approach was confirmed by assessing acute toxicities using the Common Terminology Criteria for Adverse Events v4.0 and American Urologic Association symptom scores. Results We found good stability in prostate and catheter position, with less than 1 mm shifts in each direction due to patient transfer. The median baseline American Urologic Association score was 7 (3–11), which increased to 12 (7–17) at 4 weeks and 9 (5–14) at 3 months (p = 0.003). Common Terminology Criteria for Adverse Events ≥ grade 2 genitourinary and gastrointestinal toxicities were experienced by 7% and 0% patients, respectively, at 3 months posttreatment completion. Conclusions Single-fraction HDR prostate BT can be delivered safely in an unshielded OR facility with a distant shielded treatment room using rigorous motion management checks and supplementary procedural equipment.

Purpose Post-surgery radiation can reduce the risk of loco-regional relapse in high-intermediate-risk endometrial cancer. High-dose-rate vaginal cuff brachytherapy (HDR-BRT) is an acceptable method of radiation in majority of endometrial cancer cases. Although 2D planning is frequently used for treatment based on physical examination without any imaging, measurement of the dose received by organs-at-risk (OARs) is not possible. Therefore, the present study was the first to compare dose delivered to target and OARs in 2D vs. 3D planning in patients treated with cobalt-60 source. Material and methods In this study, organs including vagina wall, bladder, rectum, and sigmoid were contoured on computed tomography (CT) scan images of 37 endometrial cancer patients, and doses delivered to organs were recorded. Statistics, such as D90, D99, V100, V150, V200, D0.1cc, D1cc, and D2cc were determined. Results D90 and D99 were lower in 3D treatment planning in comparison with 2D. Although V100 was more in 3D planning, V150 and V200 were less. Analyzing D0.1cc, D1cc, and D2cc of OARs revealed that doses given to rectum, sigmoid, and bladder were less in 3D planning compared to 2D. Conclusions Comparison of 2D and 3D planning results showed that 3D planning could deliver an appropriate dose to the target while sparing more OARs.

Purpose The purpose of this technical note was to investigate correlation of total reference air-kerma (TRAK) with volume enclosed by the prescription isodose surface in vaginal cylinder high-dose-rate (HDR) brachytherapy. Material and methods Treatment plans of 175 gynecological cancer patients treated at our institution with iridium-192 (192Ir) HDR brachytherapy using a single-channel vaginal cylinder applicator were retrospectively reviewed. Applicator size in diameter ranged from 20 mm to 40 mm. Treatment length ranged from 30 mm to 90 mm (median, 50 mm). Brachytherapy fractional dose was 5 Gy (DoseRef) prescribed to 5 mm distance from cylinder surface. Parameters TRAK (cGy), source activity during treatment (Ci), total treatment time (s), and prescription isodose surface volume ISVRef (cm3) were recorded from individual treatment plans. In each case, vaginal tissue volume (VVT) enclosed by prescription isodose was calculated by subtracting cylinder volume enclosed by the prescription isodose from ISVRef. Results Total reference air-kerma correlated with the total volume enclosed by the prescription isodose via ISVRef = 4768 × (TRAK/DoseRef)1.47. TRAK related linearly to the volume of vaginal tissue enclosed by the prescription dose via VVT = ((138.3 × TRAK) - 8.2). Secondarily, TRAK related to the treatment time through time (s) = 882 (s/cGy) × TRAK (cGy), where 882 is (1/air-kerma strength) for 10 Ci apparent activity of 192Ir source. Conclusions The correlation of TRAK to the vaginal tissue volume encompassed by the prescription dose surface yields a useful predictive equation. The TRAK treatment time relationship enables quick verification of planned treatment time by knowing TRAK in any HDR brachytherapy application.

Introduction: Brachytherapy (BT) and external beam radiation therapy (EBRT) are effective treatments for high-risk prostate cancer (PCa). However, the impact of these treatments on health-related quality of life (HRQL) remains unclear. In this study, we compared EBRT alone with EBRT plus a boost with high-dose rate (HDR)-BT to determine the impact on HRQL in patients with high-risk PCa. Material and methods: Prospective, multicenter study comparing patients with high-risk PCa treated with EBRT alone or EBRT + HDR-BT from 2004 to 2006. HRQL was assessed at baseline (pre-treatment) and periodically over the 5-year follow-up, using the SF-36 (v.2), EPIC, and FACT-G and FACT-P questionnaires. Results: A total of 129 patients were included in the study, of these, 41 received EBRT alone and 88 EBRT + HDR-BT. All patients received hormonotherapy. Baseline clinical characteristics were similar, except for a slightly higher mean number of comorbidities in the EBRT group. During follow-up, the only significant between-group difference was a greater worsening on EPIC hormonal domain in the EBRT alone group (p = 0.028). There were no significant differences in time and interaction of treatment in SF-36, and FACT-G and FACT-P questionnaires or EPIC urinary incontinence, urinary irritative-obstructive, and bowel and sexual domains over the 5-year follow-up. Oncological outcomes were similar in both groups. Conclusions: After five years of follow-up, EBRT alone or combined with HDR-BT boost had a similar impact on HRQL in patients with high-risk localized PCa. However, patients in the EBRT alone group experienced greater worsening of hormonal domain according to EPIC questionnaire.

PURPOSE: High-dose-rate (HDR) prostate brachytherapy uses volumetric imaging for treatment planning. Our institution transitioned from computed tomography (CT)-based planning to MRI-based planning with the hypothesis that improved visualization could reduce treatment-related toxicity. This study aimed to compare the patient-reported health-related quality of life (hrQOL) and physician-graded toxicity outcomes of CT-based and MRI-based HDR prostate brachytherapy. METHODS: From 2016 to 2019, 122 patients with low- or intermediate-risk prostate cancer were treated with HDR brachytherapy as monotherapy. Patients underwent CT only or CT and MRI imaging for treatment planning and were grouped per treatment planning imaging modality. Patient-reported hrQOL in the genitourinary (GU), gastrointestinal (GI), and sexual domains was assessed using International Prostate Symptom Score and Expanded Prostate Cancer Index Composite Short Form-26 questionnaires. Baseline characteristics, changes in hrQOL scores, and physician-graded toxicities were compared between groups. RESULTS: The median follow-up was 18 months. Patient-reported GU, GI, and sexual scores worsened after treatment but returned toward baseline over time. The CT cohort had a lower baseline mean International Prostate Symptom Score (5.8 vs. 7.8, p = 0.03). The other patient-reported GU and GI scores did not differ between groups. Overall, sexual scores were similar between the CT and MRI cohorts (p = 0.08) but favored the MRI cohort at later follow-up with a smaller decrease in Expanded Prostate Cancer Index Composite Short Form-26 sexual score from baseline at 18 months (4.9 vs. 19.8, p = 0.05). Maximum physician-graded GU, GI, and sexual toxicity rates of grade ≥2 were 68%, 3%, and 53%, respectively, with no difference between the cohorts (p = 0.31). CONCLUSION: Our study shows that CT- and MRI-based HDR brachytherapy results in similar rates of GU and GI toxicity. MRI-based planning may result in improved erectile function recovery compared with CT-based planning. Published by Elsevier Inc. on behalf of American Brachytherapy Society.

Purpose Brachytherapy (BT) after surgical resection of keloids reduces the risk of local recurrence, but standardization of dose/technique is lacking. Typical keloid BT treatment utilizes a single-channel source prescribed to 5-mm depth. We investigated the dosimetry of a volume-based target definition for interstitial high-dose-rate BT treatment of keloids. Methods and Materials We retrospectively identified consecutive 14 patients who had a total of 20 keloids treated with interstitial high-dose-rate BT for keloids at our institution between 2004 and 2014. Keloids were treated with a single 8 Gy fraction prescribed to 5 mm beneath the scar within 36 h of surgery. Retrospectively, a 3-mm skin high-risk clinical target volume (HR-CTV) was contoured under the scar for volume-based dose calculations. Results Mean (SD) HR-CTV was 3.91 cm3 (3.1) and mean (SD) HR-CTV dose was 11.3 Gy (3.6). Mean D90 (SD) was 62.9% (25.8) and mean V100 (SD) was 56.5% (26.4). The mean V150 (SD), V200 (SD), and V300 (SD) were as follows: 37.6% (19.9), 25.1% (14.4), and 11.3% (6.5), respectively. No local failures were reported at 9 months median followup. There were no Grade 2 or higher late toxicities. Conclusions Using a volume-based target definition, a wide range of target coverage was observed. This is likely a consequence of the curvature of the skin and the challenges of keeping the catheter equidistant from the skin across the target. Additional data are needed to define the potential clinical impact on outcomes/toxicities of dosimetric correlates with single-catheter BT keloid treatment.

Purpose This study is a comparison between revised Manchester Point A and International Commission on Radiation Units and measurements (ICRU) 89 report–recommended Point A absorbed-dose reporting in intracavitary brachytherapy for patients with cervical carcinoma. Methods and Materials The retrospective dosimetric study is based on the data of 32 patients with cervical carcinoma treated with high-dose-rate brachytherapy. Patients received 21 Gy in three fractions (7.0 Gy X three fractions) to Point A (Aflange, revised Manchester definition). All the patients were replanned with a new Point A (Aicru89) defined on CT images as per the American Brachytherapy Society/ICRU-89. The data collected were compared with the data obtained from Point A (Aflange). Results When using the Aflange plan normalization method, the mean dose of 0.1 cc, 1 cc, and 2 cc bladder volumes was 820.79 ± 207.47 cGy, 654.66 ± 152.69 cGy, and 588.91 ± 136.35 cGy, respectively. Likewise, when using the ICRU-89 Point Aicru89 normalization method, the mean dose of 0.1 cc, 1 cc, and 2 cc bladder volumes was 869.30 ± 224.67 cGy, 693.24 ± 166.20 cGy, and 616.61 ± 150.32 cGy, respectively. For the rectum, Point Aflange normalization plans, the mean dose of 0.1 cc, 1 cc, and 2 cc volumes was 589.37 ± 163.26 cGy, 487.51 ± 126.03 cGy, and 442.70 ± 111.43 cGy, respectively. Likewise, using the Aicru89 plan, the mean 0.1 cc, 1 cc, and 2 cc rectum volume was 625.07 ± 171.31 cGy, 517.50 ± 131.05 cGy, 464.94 ± 121.81 cGy, respectively. The statistical mean difference of Total Reference Air Kerma rate, V100 (cc), bladder, rectum and sigmoid, was found significant. Conclusions It has been found that the position of revised Manchester (Aflange) and ICRU-89 Point A does not match on CT images/radiograph, which resulted in variation in doses to the tumor, V100 (cc), organ at risk, and Total Reference Air Kerma.

The purpose of the study is to assess the effectiveness and toxicity of the treatment of prostate cancer (PCa) with combined radiation therapy (CRT), where high dose rate brachytherapy (HDR-BT) "boost". Materials and methods: CRT was carried out in 98 patients of high-risk and extremely high-risk PCa. External part of treatment (conformal external radiation therapy) provided total dose 46-50 Gy with a single focal dose (SFD) 2 Gy to the prostate gland (PG), seminal vesicles and regional lymphatic zones. Two regimes of "boost" to the PG and seminal vesicles were used: in the first group – two fractions of 10 Gy (81 patients), in the second - 15 Gy (17 patients). Results: median follow-up equals: I group - 57.5 months, II group - 55.2. Three- and five-year survival without biochemical progression in group I - 75.4% and 69.0%, II group - 76.4% and 52.9%, respectively. Similar indicators regardless of the CRT regime in groups of different risk of relapse were equal: high risk - 84.6% and 75.9%, extremely high risk - 69.4% and 60.7%, respectively (p=0.05). There were no late radiation genitourinary and gastrointestinal complications of 4-5 degrees. The most significant variants of late disorders were the formation of urethra stricture (one patient of the I group) and stenosis of the rectum (one patient of the II group). Late genitourinary radiation toxicity (L-GURT) was mainly represented by changes that can be characterized as 1 degree (RTOG/CTCAE): I group - from 40.6% to 53.2%, II - 18.8% to 35.3%. Conclusions: the studied CRT regimes showed perfectly acceptable survival rates with no signs of biochemical progression and radiation toxicity during the five-year period of follow-up.

Purpose To evaluate our institutional experience of minimally invasive tumor bed implantation (MITBI) during breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) to deliver peri-operative high-dose-rate brachytherapy (PHDRBT) as accelerated minimal breast irradiation (AMBI) or anticipated boost (A-PHDRBT-boost). Material and methods Patients older than 40, with clinical and radiological unifocal DCIS < 3 cm were considered potential candidates for accelerated partial breast irradiation (APBI) and were implanted during BCS using MITBI-technique. Patients who in final pathology reports showed free margins and no other microscopic tumor foci, received AMBI with PHDRBT (3.4 Gy BID in 5 days). Patients with adverse features received A-PHDRBT-boost with post-operative external beam radiotherapy (EBRT). Results Forty-one patients were implanted, and 36 were treated and analyzed. According to final pathology, 24 (67%) patients were suitable for AMBI and 12 (33%) were qualified for A-PHDRBT-boost. Reoperation rate for those with clear margins was 16.6% (6/36); this rate increased to 33% (4/12) for G3 histology, and 66% (4/6) were rescued using AMBI. Early complications were documented in 5 patients (14%). With a median follow-up of 97 (range, 42-138) months, 5-year rates of local, elsewhere, locoregional, and distant control were all 97.2%. 5-year ipsilateral breast tumor recurrence rates (IBTR) were 5.6% (2/36), 8.3% (2/24) for AMBI, and 0% (0/12) for A-PHDRBT-boost patients. Both instances of IBTR were confirmed G3 tumors in pre-operative biopsies; no IBTR was documented in G1-2 tumors. Cosmetic outcomes were excellent/good in 96% of AMBI vs. 67% in A-PHDRBT-boost (p = 0.034). Conclusions The MITBI-PHDRBT program allows selection of patients with excellent prognoses (G1-2 DCIS with negative margins and no multifocality), for whom AMBI could be a good alternative with low recurrence rate, decrease of unnecessary radiation, treatment logistics improvement, and over-treatment reduction. Patients whose pre-operative biopsy showed G3 tumor, presents with inferior local control and more risk of reoperation due to positive margins.

PURPOSE Our objective was to demonstrate the efficacy of a telehealth training course on high-dose-rate (HDR) brachytherapy for gynecologic cancer treatment for clinicians in low- and middle-income countries (LMICs) METHODS A 12-week course consisting of 16 live video sessions was offered to 10 cancer centers in the Middle East, Africa, and Nepal. A total of 46 participants joined the course, and 22 participants, on average, attended each session. Radiation oncologists and medical physicists from 11 US and international institutions prepared and provided lectures for each topic covered in the course. Confidence surveys of 15 practical competencies were administered to participants before and after the course. Competencies focused on HDR commissioning, shielding, treatment planning, radiobiology, and applicators. Pre- and post-program surveys of provider confidence, measured by 5-point Likert scale, were administered and compared. RESULTS Forty-six participants, including seven chief medical physicists, 16 senior medical physicists, five radiation oncologists, and three dosimetrists, representing nine countries attended education sessions. Reported confidence scores, both aggregate and paired, demonstrated increases in confidence in all 15 competencies. Post-curriculum score improvement was statistically significant ( P < .05) for paired respondents in 11 of 15 domains. Absolute improvements were largest for confidence in applicator commissioning (2.3 to 3.8, P = .009), treatment planning system commissioning (2.2 to 3.9, P = .0055), and commissioning an HDR machine (2.2 to 4.0, P = .0031). Overall confidence in providing HDR brachytherapy services safely and teaching other providers increased from 3.1 to 3.8 and 3.0 to 3.5, respectively. CONCLUSION A 12-week, low-cost telehealth training program on HDR brachytherapy improved confidence in treatment delivery and teaching for clinicians in 10 participating LMICs.

Prostate cancer is one of the most common types of cancer. If identified early, treatment can be very effective, but morbidity rates are higher in older patients and in cases where the cancer is identified in the later stages. Three main treatment options are surgery, external beam radiotherapy and brachytherapy. Professor Yasuo Yoshioka, Radiation Oncology Department, Cancer Institute Hospital of Japanese Foundation for Cancer Research, believes brachytherapy to be the most effective treatment option for prostate cancer patients and is working to improve the methods by which brachytherapy is performed in order to further enhance its effectiveness, while reducing the amount of damage to the patient during the course of treatment. Yoshioka and his team are focused on high-dose-rate (HDR) brachytherapy as they believe it has advantages over low-dose-rate (LDR) brachytherapy, including its ability to treat advanced-stage patients, the ability to adjust the strength of radiation at each source position and the fact that no radiation sources will be left in the patient's body after treatment. Yoshioka reported the world's first HDR monotherapy experience for prostate cancer and, over the past decade, he and his team have been refining the procedure in order to maximise the effect of the treatment while minimising damage to the patient.

Purpose Technological advances with commercial production of surface applicators allowed high-dose-rate (HDR) afterloading brachytherapy to overpass challenges associated with the delivery of superficial radiation when treating non-melanoma skin cancer (NMSC). We reviewed our single institutional experience using HDR to treat basal (BCC) and squamous cell (SCC) carcinomas. Material and methods A retrospective review of all patients treated with HDR and Leipzig-style applicators for NMSC at the Radiation Oncology Department, AC Camargo Cancer Center, from March 2013 to December 2018 was performed. Results Seventy-one patients with 101 lesions (BCCs, 69.3% or n = 70) and median age 80 (range, 51-102) years old were evaluated. The median follow-up was 42.8 (range, 12-82) months. The 3-year and 5-year actuarial local control (LC) rates were 97.9% and 87.2%, respectively. On univariate analysis, treatments with EQD2 less than 50 Gy (p < 0.001) and dose per fraction smaller than 3 Gy (p < 0.001) were found to be statistically significant predictive factors of a worse outcome. On multivariate analysis, SCC had a worse prognosis over BCC (p = 0.007, HR = 2.3, CI: 1.2-6.6). All patients developed some degree of acute side effects graded 1 to 2. Grade 3 acute side effects were observed in 9 (8.9%) patients. Moreover, severe late side effects (grade 3), hypopigmentation, and telangiectasia were observed in 4 (3.9%) patients. No grade 4 acute or late side effects were seen in this cohort. Conclusions HDR offers a convenient treatment schedule for patients and is associated with excellent LC. The most effective regimen, in terms of dose and fractionation, to treat superficial NMSC with HDR remains uncertain, but a moderate minimum EQD2 dose of 50 Gy should be used.

Purpose To record and report dosimetric and clinical outcomes of interstitial brachytherapy using cobalt-60 (60Co) source in cervical cancer. Material and methods Seventy patients who underwent external beam radiotherapy with dose of 45 Gy in 25 fractions, followed by interstitial brachytherapy (ISBT) 6.5 Gy × 4 fractions were included into this study. The ISBT applicators were inserted under combined spinal and epidural anesthesia. Computed tomography (CT) simulation was performed and axial CT images were transferred to treatment planning system. High-risk clinical target volume (CTVHR) and organs at risks (OARs) were contoured. Four fractions of 6.5 Gy were prescribed to CTVHR using inverse planning technique. Patients were followed-up for 3 years. Dosimetric parameters and clinical outcomes were recorded and compared with available literature. Results Seventy patients with FIGO stage IIB-IVA were included in the study. The median EQD2 of 2 cm3 of bladder, rectum, sigmoid and D90 CTVHR were 70 Gy (53-75 Gy), 64 Gy (51-71 Gy), 48 Gy (44-72 Gy), and 77 Gy (70-86 Gy), and dose homogeneity index (DHI), dose non-uniformity ratio (DNR), coverage index (CI), overdose volume index (OI), and conformal index (COIN) were 0.58 (0.39-0.78), 0.42 (0.22-0.61), 0.87 (0.59-0.97), 0.19 (0.09-0.30) and 0.74 (0.52-0.85), respectively. Local control rate at 2 years was 87.14%. Eight patients had local recurrence and one patient had lung metastasis. Also, two patients with local recurrence had recto-vaginal fistula. Two patients had grade 2 proctitis (2.8%) and one patient developed grade 3 proctitis (1.4%). There was no grade 2 or higher bladder toxicity. Conclusions The dosimetric parameters, local control and toxicities of high-dose-rate interstitial brachytherapy in cervical cancer patients treated by 60Co radioactive source are similar, compared to available literature using iridium-192 (192Ir) source.

Purpose This is a study of our experience with Co-60 high dose rate brachytherapy (HDR BT) from a tertiary care center. Materials and Methods One thousand patients were treated with Cobalt-based HDR BT for more than 6 years. The practice of BT was analyzed for clinical outcome, physical, radiobiological, and technical aspects. Results Among those 1000 patients, 906 (90.6%) patients had gynecologic cancer, 29 (2.9%) patients had intraluminal BT, 63 (6.3%) hadhead &neck (2.1%), keloid (2.1%) and mold BT (2.1%), and 2 (0.2%) had sarcoma. Dose rate decreased by 48.9%, and treatment time increased from 9.33 to 18.27 min over 5 years. No patients treatment was abandoned because of machine-related problems. Conclusion Cobalt-based HDR BT is preferable in terms of lesser source exchanges, relatively uniform treatment time, quality assurance requirement, and cost.

Purpose Leipzig-style applicators for surface brachytherapy are traditionally used with a single-source dwell position. This study explores the feasibility of using multiple-source dwell positions (“multidwell”) to improve the dose coverage and applicability of Leipzig-style applicators. Methods and Materials A virtual model of the Leipzig-style applicator was commissioned for a model-based dose calculation algorithm (MBDCA) and compared against American Association of Physicists in Medicine working group 186 benchmarking data sets and ionization chamber point measurements. An absolute dosimetry technique based on radiochromic film was used to validate both single-dwell and multidwell plans. Results Dose distributions generated from the MBDCA-based virtual model were consistent with working group data sets, ion chamber measurements, and radiochromic film analysis. In one multidwell configuration, at 3 mm prescription depth, the 80% isodose width was increased to 25 mm, compared with 15 mm in the same dimension for a single-dwell delivery. In the same multidwell configuration, the flatness, measured as >98% isodose line, was more than doubled to 8 mm, compared with 3 mm in the same dimension. For multidwell plans, 2-D planar agreement between radiochromic film and MBDCA exceeded 93% in gamma analysis (3%/1 mm criteria). Submillimeter positional agreement was found, with a total dosimetric uncertainty of 4.5% estimated for the entire system. Conclusions Leipzig-style surface applicators with multiple-source dwell positions have been benchmarked against radiochromic film dosimetry. Results show that the clinically viable coverage area can be increased significantly.

Highlights • Local recurrence of prostate cancer may be treated with salvage therapies. • Focal salvage high dose rate brachytherapy provides good biochemical control. • Severe genitourinary and gastrointestinal toxicities are low., Introduction Isolated local recurrence of prostate cancer following primary radiotherapy or brachytherapy may be treated with focal salvage high dose rate brachytherapy, although there remains an absence of high quality evidence to support this approach. Methods Men with prostate cancer treated consecutively between 2015 and 2018 using 19 Gy in a single fraction high dose rate brachytherapy (HDR) for locally recurrent prostate cancer were identified from an institutional database. Univariable analysis was performed to evaluate the relationship between patient, disease and treatment factors with biochemical progression free survival (bPFS). Results 43 patients were eligible for evaluation. Median follow up duration was 26 months (range 1–60). Median bPFS was 35 months (95% confidence interval 25.6–44.4). Kaplan-Meier estimates for bPFS at 1, 2 and 3 years post salvage were 95.2%, 70.6% and 41.8% respectively. On univariable Cox regression analysis, only nadir PSA was significantly associated with bPFS although the majority of patients were also treated with androgen deprivation therapy. Only one late grade 3 genitourinary toxicity was observed. Conclusion Focal salvage HDR brachytherapy may provide good biochemical control with a low risk of severe toxicity. Further evaluation within clinical trials are needed to establish its role in the management of locally recurrent prostate cancer.

Purpose The purpose of this study is to evaluate the feasibility of using deformable image registration algorithms to improve high-dose-rate high-risk clinical target volume (HR-CTV) delineation between preapplicator implantation MRI (pre-MRI) and postapplicator implantation CT (post-CT) in the treatment of locally advanced cervical cancer (LACC). Method and materials Twenty-six patients were identified for the study. Regions of interest were segmented on MRI and CT. A HR-CTV was delineated on pre-MRI and compared with the previously contoured HR-CTV on the post-CT. Two commercially available algorithms, ANACONDA (anatomically constrained) and MORFEUS (biomechanical model based) with various controlling structure settings, including the cervix, uterus, etc., were used to deform pre-MRI to post-CT. MRI-to-CT deformed targets are denoted as HR-CTV’. Quantitative deformation metrics include Dice index, distance to agreement, and center of mass displacement. Qualitative clinical usefulness of deformations was scored based on HR-CTV identification on CT images. Results For ANACONDA and MORFEUS deformations, using a cervix controlling region of interest resulted in the highest Dice, lowest distance to agreement, and lowest center of mass displacement for HR-CTV′. With MORFEUS deformations, the deformed HR-CTV’ proved clinically useful in 23 patients. Conclusions Prebrachytherapy implantation MRI can aid target contours for CT-based brachytherapy through ANACONDA or MORFEUS algorithms with appropriate parameter selection for LACC patients.

ObjectiveCompared with 3D-planned pelvic radiation, intensity-modulated radiation therapy (IMRT) has been shown to reduce acute toxicity in cervical cancer patients after radical hysterectomy. This study evaluated late toxicity and patterns of failure after post-operative pelvic IMRT interdigitated weekly with high dose rate brachytherapy.MethodsThis retrospective study included 53 cervical cancer patients treated between January 2006 and August 2019 with radical hysterectomy, lymphadenectomy, and post-operative IMRT and high dose rate brachytherapy. The decision to include chemotherapy was made by the treating gynecologic oncologist based on patient-specific criteria including positive pelvic lymph nodes, positive surgical margins, or positive parametrial invasion. The actuarial rates of genitourinary and gastrointestinal toxicity, vaginal cuff/regional nodal/distant failure, and overall survival were calculated using the Kaplan–Meier method.ResultsMedian follow-up was 70 months (range 5.4–148) months and age at diagnosis was 47 (range 24–73) years. The 2018 International Federation of Gynecology and Obstetrics (FIGO) clinical stages were IB1 (n=19), IB2 (n=7), IIB (n=7), IIIC1 (n=19), and IIIC2 (n=1). Median radiation dose delivered in 160 cGy daily fractions was 5120 (range 4640–5120) cGy. Median brachytherapy dose prescribed to the vaginal surface delivered in six weekly fractions was 2400 (range 1200–4800) cGy. Concurrent chemotherapy was delivered in 35 (66%) patients. There were no acute grade >3 genitourinary or gastrointestinal toxicities. Late grade >3 occurred in two (3.8%) patients, including a small bowel obstruction and a ureteral stricture. The 5-year actuarial rate for gastrointestinal or genitourinary toxicity was 1.9%. There were no vaginal cuff recurrences. The 5-year actuarial rates for regional nodal failure, distant failure outside the radiation field, any failure, and overall survival were 11%, 11%, 14%, and 85%, respectively.ConclusionsPost-operative IMRT with high dose rate brachytherapy for patients with cervical cancer is associated with excellent outcomes and limited rates of radiation-related non-hematologic toxicity.