Brachytherapy on-a-chip: a clinically-relevant approach for radiotherapy testing in 3d biology.

We describe the first microfluidic device for in vitro testing of brachytherapy (BT), with applications in translational cancer research. Our PDMS-made BT-on-chip system allows highly precise manual insertion of clinical BT seeds, reliable dose calculation using standard clinically-used TG-43 formalism and easy culture of naturally hypoxic spheroids in less than 3 days, thereby increasing the translational potential of the device. As the BT-on-chip platform is designed to be versatile, we showcase three different gold-standard post-irradiation bioassays and recapitulate, for the first time on-chip, key clinical observations such as dose rate effect and hypoxia-induced radioresistance. Our results suggest that BT-on-chip can be used to safely and efficiently integrate BT and radiotherapy to translational research and drug development pipelines, without expensive equipment or complex workflows.

Treatment of malignant airway obstruction with Y-shape sigma stent loaded with I125 seeds installed via rigid bronchoscopy.

PURPOSE: To summarize and analyze the safety and efficacy of a Y-shape Sigma stent loaded with I125 in patients with inoperable malignant main airway obstruction. METHODS: This study was approved by the Institutional Ethics Committee, and a written informed consent was obtained from each participant. A Y-shape Sigma stent loaded with I125 was placed under vision from rigid bronchoscopy. The primary endpoint was alleviation of symptoms and improvement of Karnofsky Performance Status (KPS) score, and the secondary endpoint was complications and technical success. RESULTS: From November 2018 through June 2023, total 33 patients with malignant airway obstruction were palliatively treated by installing Y-shape Sigma stents loaded with I125. The airway lumen was immediately restored and the average airway opening significantly increased to 70 ± 9.4% after the procedure from baseline 30.2 ± 10.5% (p < 0.05). Average KPS score was improved from baseline 30.0 ± 10.0 to 70.0 ± 10.0 (p < 0.05) as well as PaO2 from baseline 50.1 ± 15.4 mmHg to 89.3 ± 8.6 mmHg (p < 0.05). The technical success rate of placing the stent in this study was 73%, and adverse events or complications including bleeding, I125 loss, and airway infection occurred during or after the procedure. CONCLUSION: Placement of Y-shape Sigma stents under vision from rigid bronchoscopy in the patients with malignant airway obstruction is feasible and it immediately alleviates dyspnea and significantly improves quality of life.

A systematic review of combined surgery and brachytherapy approaches for children and young people with relapsed and refractory rhabdomyosarcoma (Local-REFoRMS).

Approximately one third of children with rhabdomyosarcoma relapse or have refractory disease. Treatment approaches include a combination of systemic therapies and local therapies, directed at tumour site(s). This review was conducted to evaluate the effectiveness and safety of the combination of surgery and brachytherapy as local therapy for treating children and young people with relapsed/refractory rhabdomyosarcoma. This review identified studies based on a previous systematic review looking at the treatments for children and young people under 18 years old with relapsed/refractory rhabdomyosarcoma. Studies conducted after 2000 were included. Survival outcomes, relapse rates, adverse events and functional outcomes were extracted. From 16,965 records identified in the baseline systematic review, 205 included the words 'AMORE' or 'brachytherapy', and were screened for eligibility in this substudy. Thirteen studies met the inclusion criteria for Local-REFoRMS, including over 55 relapsed and refractory rhabdomyosarcoma patients. Most studies were retrospective cohort studies conducted within Europe. Most patients had embryonal disease within the head and neck or bladder/prostate regions, and received local therapy for first relapse. Approximately one quarter of patients relapsed following surgery and brachytherapy, with local relapses occurring more than metastatic relapse. Adverse events and functional outcomes were infrequently reported, but related to the site of surgery and brachytherapy. Study quality was limited by inconsistent reporting and potential selection bias. Outcomes following surgery and brachytherapy for a selected group of relapsed and refractory rhabdomyosarcoma show reasonable benefits, but reporting was often unclear and based on small sample sizes.

Radiomics signature for dynamic changes of tumor-infiltrating CD8+ T cells and macrophages in cervical cancer during chemoradiotherapy.

BACKGROUND: Our previous study suggests that tumor CD8+ T cells and macrophages (defined as CD68+ cells) infiltration underwent dynamic and heterogeneous changes during concurrent chemoradiotherapy (CCRT) in cervical cancer patients, which correlated with their short-term tumor response. This study aims to develop a CT image-based radiomics signature for such dynamic changes. METHODS: Thirty cervical squamous cell carcinoma patients, who were treated with CCRT followed by brachytherapy, were included in this study. Pre-therapeutic CT images were acquired. And tumor biopsies with immunohistochemistry at primary sites were performed at baseline (0 fraction (F)) and immediately after 10F. Radiomics features were extracted from the region of interest (ROI) of CT images using Matlab. The LASSO regression model with ten-fold cross-validation was utilized to select features and construct an immunomarker classifier and a radiomics signature. Their performance was evaluated by the area under the curve (AUC). RESULTS: The changes of tumor-infiltrating CD8+T cells and macrophages after 10F radiotherapy as compared to those at baseline were used to generate the immunomarker classifier (AUC= 0.842, 95% CI:0.680-1.000). Additionally, a radiomics signature was developed using 4 key radiomics features to predict the immunomarker classifier (AUC=0.875, 95% CI:0.753-0.997). The patients stratified based on this signature exhibited significant differences in treatment response (p = 0.004). CONCLUSION: The radiomics signature could be used as a potential predictor for the CCRT-induced dynamic alterations of CD8+ T cells and macrophages, which may provide a less invasive approach to appraise tumor immune status during CCRT in cervical cancer compared to tissue biopsy.

Brachyterapy: The radiation oncologist opinion.

The role of the radiation oncologist in the management of patients affected by prostate cancer is increasingly considered thanks to important technological innovations that have marked the radiotherapeutic approach in its three main fields: external beam radiotherapy (EB-RT), brachytherapy (interventional radiotherapy, I-RT), and metabolic radiotherapy (M-RT) through the use of new radiopharmaceuticals. Regarding the modern brachytherapy, the introduction of intensity-modulated techniques (IM-IRT), thanks to the implementation of HDR remote-after loading machines, and image-guided techniques (IG-IRT), has led to advantages in optimizing dose distribution after implantation with the possibility of modulating the dose according to the intraprostatic dominant lesions, limiting the dose to the surrounding tissues with improvement in local control and a significant reduction in side effects. I-RT today represents a safe, scientifically established, effective and well-tolerated treatment for patients affected by prostate cancer. Like most special techniques, in order to obtain the best results, it must be performed in centers with a high volume of activity and consolidated experience with an interdisciplinary approach.

Results of Definitive (Chemo)radiotherapy Using Computed Tomography-based Brachytherapy for Cervical Cancer.

BACKGROUND/AIM: Concurrent cisplatin-based chemoradiotherapy (CCRT) is the standard treatment for locally advanced cervical cancer. Especially, CCRT with magnetic resonance imaging (MRI) or computed tomography-based image-guided brachytherapy (CT-based 3D-IGBT) for cervical cancer has resulted in good LC rates. However, progression-free survival (PFS) and overall survival (OS) rates for locally advanced cervical cancer are still low and could be improved. The aim of the study was to evaluate treatment efficacy and late toxicity of external beam radiotherapy (EBRT) and CT-based IGBT with or without concurrent chemotherapy in patients with squamous cell carcinoma of the uterine cervix and investigate patterns of failure. PATIENTS AND METHODS: We retrospectively analyzed clinical data of cervical squamous cell carcinoma patients treated with definitive radiotherapy with or without concurrent chemotherapy at Saitama Medical University International Medical Center. Local control (LC), PFS, patterns of failure, and late toxicity were the evaluated outcomes. RESULTS: Overall, 290 patients were enrolled in the study. Median follow-up was 51.5 months. During follow-up, 74 patients developed recurrence: 10 patients with intra-pelvic failure only, 45 with extra-pelvic failure only, and 19 with both. The 3-year LC was 100% for T1b-T2a, 96.8% for T2b, 89.5% for T3b, and 88.5% for T4 disease. The 3-year PFS was 100% for stage IB-IIA, 89.0% for stage IIB, 70.7% for stage IIIB, 72.6% for stage IIIC1r, and 40.1% for stage IVA. The incidence of grade 3-4 gastrointestinal and genitourinary toxicities was 3.0% and 1.7%, respectively. CONCLUSION: Combination of EBRT and CT-based IGBT with or without concurrent chemotherapy produced favorable LC with acceptable rates of late toxicities. However, extra-pelvic failures frequently occurred and PFS was less satisfactory in patients with stage III-IVA disease, which indicated the need for additional treatment in these patients.

Apparent diffusion coefficient values predict response to brachytherapy in bulky cervical cancer.

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.

Effective Differences between 2D and 3D Planned Brachytherapy in Lung Cancer: An Institutional Retrospective Study.

Background and Objectives: Advanced lung cancer is usually manifested by endoluminal tumor propagation, resulting in central airway obstruction. The objective of this study is to compare the high dose rate brachytherapy treatment outcomes in non-small-cell lung cancer (NSCLC) depending on the treatment planning pattern-two-dimension (2D) or three-dimension (3D) treatment planning. Materials and Methods: The study was retrospective and two groups of patients were compared in it (a group of 101 patients who underwent 2D planned high-dose-rate endobronchial brachytherapy (HDR-EBBT) in 2017/18 and a group of 83 patients who underwent 3D planned HDR-EBBT between January 2021 and June 2023). Results: In the group of 3D planned brachytherapy patients, there was a significant improvement in terms of loss of symptoms of bronchial obstruction (p = 0.038), but no improvement in terms of ECOG PS (European Cooperative Oncology Group Performance Status) of the patient (p = 0.847) and loss of lung atelectasis (if there was any at the beginning of the disease) (p = 0.781). Two-year overall survival and time-to-progression periods were similar for both groups of patients (p = 0.110 and 0.154). Fewer treatment complications were observed, and 91.4% were in 3D planned brachytherapy (BT) patients. Conclusions: Three-dimensionally planned HDR-EBBT is a suggestive, effective palliative method for the disobstruction of large airways caused by endobronchial lung tumor growth. Independent or more often combined with other types of specific oncological treatment, it certainly leads to the loss of symptoms caused by bronchial obstruction and the improvement of the quality of life of patients with advanced NSCLC. Complications of the procedure with 3D planning are less compared to 2D planned HDR-EBBT.

Prognostic difference between surgery and external radiation in patients with stage I liver cancer based on competitive risk model and conditional survival rate.

PURPOSE: This study aimed to assess the difference in prognosis of patients with early-stage liver cancer after surgery or external radiation. METHODS: Between 2010 and 2015, 2155 patients with AJCC 7th stage I liver cancer were enrolled in the SEER database. Among these, 1972 patients had undergone surgery and 183 had undergone external beam radiation. The main research endpoints were overall survival (OS) and disease-specific survival (DSS). The competitive risk model was used to calculate the risk ratio of liver cancer-specific deaths when there was a competitive risk. Propensity Score Matching (PSM) method using a 1:1 ratio was used to match confounders such as sex, age, and treatment method. Conditional survival was dynamically assessed for patient survival after surgery or external radiation. RESULTS: Multivariate analysis of the competitive risk model showed that age, disease diagnosis time, grade, and treatment [surgery and external beam radiation therapy (EBRT)] were independent prognostic factors for patients with hepatocellular carcinoma. Surgery had a higher survival improvement rate than that of EBRT. As the survival of patients with liver cancer increased, the survival curve of surgery declined more slowly than that of radiotherapy patients and stabilized around 3 years after surgery. The survival curve of radiotherapy patients significantly dropped within 4 years and then stabilized. CONCLUSION: Surgery was better than EBRT for patients with stage I liver cancer. Close follow-up was required for 3 years after surgery or 4 years after external radiation. This study can help clinicians make better informed clinical decisions.

Aleatoric and epistemic uncertainty extraction of patient-specific deep learning-based dose predictions in LDR prostate brachytherapy.

Objective.In brachytherapy, deep learning (DL) algorithms have shown the capability of predicting 3D dose volumes. The reliability and accuracy of such methodologies remain under scrutiny for prospective clinical applications. This study aims to establish fast DL-based predictive dose algorithms for low-dose rate (LDR) prostate brachytherapy and to evaluate their uncertainty and stability.Approach.Data from 200 prostate patients, treated with125I sources, was collected. The Monte Carlo (MC) ground truth dose volumes were calculated with TOPAS considering the interseed effects and an organ-based material assignment. Two 3D convolutional neural networks, UNet and ResUNet TSE, were trained using the patient geometry and the seed positions as the input data. The dataset was randomly split into training (150), validation (25) and test (25) sets. The aleatoric (associated with the input data) and epistemic (associated with the model) uncertainties of the DL models were assessed.Main results.For the full test set, with respect to the MC reference, the predicted prostateD90metric had mean differences of -0.64% and 0.08% for the UNet and ResUNet TSE models, respectively. In voxel-by-voxel comparisons, the average global dose difference ratio in the [-1%, 1%] range included 91.0% and 93.0% of voxels for the UNet and the ResUNet TSE, respectively. One forward pass or prediction took 4 ms for a 3D dose volume of 2.56 M voxels (128 × 160 × 128). The ResUNet TSE model closely encoded the well-known physics of the problem as seen in a set of uncertainty maps. The ResUNet TSE rectum D2cchad the largest uncertainty metric of 0.0042.Significance.The proposed DL models serve as rapid dose predictors that consider the patient anatomy and interseed attenuation effects. The derived uncertainty is interpretable, highlighting areas where DL models may struggle to provide accurate estimations. The uncertainty analysis offers a comprehensive evaluation tool for dose predictor model assessment.

Treatment intensification strategies for men undergoing definitive radiotherapy for high-risk prostate cancer.

PURPOSE: Treatment intensification of external beam radiotherapy (EBRT) plays a crucial role in the treatment of high-risk prostate cancer. METHODS: We performed a critical narrative review of the relevant literature and present new developments in evidence-based treatment intensification strategies. RESULTS: For men with high-risk prostate cancer, there is strong evidence to support prolonging androgen deprivation therapy (ADT) to 18-36 months and escalating the dose to the prostate using a brachytherapy boost. A potentially less toxic alternative to a brachytherapy boost is delivering a focal boost to dominant intraprostatic lesions using EBRT. In patients who meet STAMPEDE high-risk criteria, there is evidence to support adding a second-generation anti-androgen agent, such as abiraterone acetate, to long-term ADT. Elective pelvic lymph node irradiation may be beneficial in select patients, though more prospective data is needed to elucidate the group of patients who may benefit the most. Tumor genomic classifier (GC) testing and advanced molecular imaging will likely play a role in improving patient selection for treatment intensification as well as contribute to the evolution of treatment intensification strategies for future patients. CONCLUSION: Treatment intensification using a combination of EBRT, advanced hormonal therapies, and brachytherapy may improve patient outcomes and survival in men with high-risk prostate cancer. Shared decision-making between patients and multidisciplinary teams of radiation oncologists, urologists, and medical oncologists is essential for personalizing care in this setting and deciding which strategies make sense for individual patients.

Calibration system correction factor for measuring the reference air kerma rate (RAKR) applied to high dose rate192Ir sources (HDR).

The aim of this study was to use computer simulation to analyze the impact of the aluminum fixing support on the Reference Air Kerma (RAK), a physical quantity obtained in a calibration system that was experimentally developed in the Laboratory of Radiological Sciences of the University of the State of Rio de Janeiro (LCR-UERJ). Correction factors due to scattered radiation and the geometry of the192Ir sources were also sought to be determined. The computational simulation was validated by comparing some parameters of the experimental results with the computational results. These parameters were: verification of the inverse square law of distance, determination of (RAKR), analysis of the source spectrum with and without encapsulation, and the sensitivity curve of the Sourcecheck 4PI ionization chamber response, as a function of the distance from the source along the axial axis, using the microSelectron-v2 (mSv2) and GammaMedplus (GMp) sources. Kerma was determined by activity in the Reference air, with calculated values of 1.725 × 10-3U. Bq-1and 1.710 × 10-3U. Bq-1for the ionization chamber NE 2571 and TN 30001, respectively. The expanded uncertainty for these values was 0.932% and 0.919%, respectively, for a coverage factor (k = 2). The correction factor due to the influence of the aluminum fixing support for measurements at 1 cm and 10 cm from the source was 0.978 and 0.969, respectively. The geometric correction factor of the sources was ksg= 1.005 with an expanded uncertainty of 0.7% for a coverage factor (k = 2). This value has a difference of approximately 0.2% compared to the experimental values.

Predicting treatment plan approval probability for high-dose-rate brachytherapy of cervical cancer using adversarial deep learning.

Objective.Predicting the probability of having the plan approved by the physician is important for automatic treatment planning. Driven by the mathematical foundation of deep learning that can use a deep neural network to represent functions accurately and flexibly, we developed a deep-learning framework that learns the probability of plan approval for cervical cancer high-dose-rate brachytherapy (HDRBT).Approach.The system consisted of a dose prediction network (DPN) and a plan-approval probability network (PPN). DPN predicts organs at risk (OAR)D2ccand CTVD90%of the current fraction from the patient's current anatomy and prescription dose of HDRBT. PPN outputs the probability of a given plan being acceptable to the physician based on the patients anatomy and the total dose combining HDRBT and external beam radiotherapy sessions. Training of the networks was achieved by first training them separately for a good initialization, and then jointly via an adversarial process. We collected approved treatment plans of 248 treatment fractions from 63 patients. Among them, 216 plans from 54 patients were employed in a four-fold cross validation study, and the remaining 32 plans from other 9 patients were saved for independent testing.Main results.DPN predicted equivalent dose of 2 Gy for bladder, rectum, sigmoidD2ccand CTVD90%with a relative error of 11.51% ± 6.92%, 8.23% ± 5.75%, 7.12% ± 6.00%, and 10.16% ± 10.42%, respectively. In a task that differentiates clinically approved plans and disapproved plans generated by perturbing doses in ground truth approved plans by 20%, PPN achieved accuracy, sensitivity, specificity, and area under the curve 0.70, 0.74, 0.65, and 0.74.Significance.We demonstrated the feasibility of developing a novel deep-learning framework that predicts a probability of plan approval for HDRBT of cervical cancer, which is an essential component in automatic treatment planning.

Long-term results of intraoperative multicatheter breast implant (IOMBI) for accelerated partial breast irradiation (APBI) on early breast cancer patients.

BACKGROUND AND PURPOSE: Multicatheter breast brachytherapy is a standard technique for accelerated partial breast irradiation (APBI) in early breast cancer patients. Intraoperative multicatheter breast implant (IOMBI) followed by perioperative high-dose-rate brachytherapy (PHDRBT) offers a novel and advantageous approach. We present long-term oncological, toxicity, and cosmesis outcomes for a well-experienced single institution. MATERIALS AND METHODS: Eligible women aged ≥ 40 years with clinically and radiologically confirmed unifocal invasive or in situ ≤ 3 cm breast tumors underwent IOMBI during breast-conserving surgery. Patients meeting APBI criteria by definitive pathologic results received 3.4 Gy × 10fx with PHDRBT. Patients not suitable for APBI received PHDRBT-boost followed by WBRT. RESULTS: A total of 171 patients underwent IOMBI during BCS, 120 patients (70.1 %) were suitable for APBI and 51 (29.8 %) for anticipated PHDRBT-boost. The median age was 61 years (range: 40-78), the median tumor size was 1.1 cm (range: 0.2-3.5), with a histological diagnosis of invasive ductal carcinoma in 78.9 % and ductal in situ in 21.1 %. A median of 9 catheters (range: 4-14) were used. For APBI, the median CTV and V100 were 40.8 cc (range: 8.6-99) and 35.4 cc (range: 7.2-94). The median of healthy breast tissue irradiated represents 7.2 % (range: 2.3-28 %) and the median local treatment duration was 10 days (range: 7-16). With a median follow-up of 8.8 years (range: 0.3-16.25), the 8-year local, locoregional, and distant control rates were 99 %, 98.1 %, and 100 %. G1-G2 late-toxicity rate was 53.4 %. Long-term cosmetic evaluation was excellent-good in 90.8 %. CONCLUSION: IOMBI&PHDRBT program reports excellent long-term oncological outcomes, with a reduction from unnecessary irradiation exposure which translates into low long-term toxicity and good cosmesis outcomes, especially on well-selected APBI patients.

Less than whole uterus irradiation for patients with locally advanced cervical cancer.

INTRODUCTION: Current consensus guidelines for definitive cervical cancer intensity modulated radiation therapy (IMRT) recommend inclusion of the entire uterus within the clinical target volume, however this is debated. We aimed to evaluate outcomes of patients with cervical cancer who were treated with less than whole uterus irradiation. METHODS: We identified 109 patients with FIGO Stage IB-IVA cervical cancer treated definitively with concurrent chemoradiation, including IMRT and brachytherapy, from 2010 to 2022 at a single institution where the practice was to include the gross cervix tumor with an internal target volume with differences in bladder filing accounted for, plus additional 5 mm planning target volume (PTV) margin. Local, regional, and distant recurrences were analyzed using competing risk methods, and a Wilcoxon rank sum test was performed to assess differences in dose to organs at risk based on the proportion of the uterus included in the PTV, with the median proportion of the uterus included (75 %) used as the cut-point. RESULTS: The median follow-up time was 65 months (range 3-352 months). The 2-year cumulative incidence of LR for the entire cohort was 4.2 % (95 % confidence interval [CI] 1.3-9.7). Compared with patients who had ≥ 75 % of the uterus included in the PTV, patients who had < 75 % of the uterus included in the PTV had significantly lower bowel D200cc (p = 0.02). The cumulative incidence of local failure (LR) was not significantly different between the two groups. CONCLUSIONS: Including less than the whole uterus for definitive cervix cancer IMRT does not seem to compromise local control. Less than whole uterus irradiation could be considered for carefully selected cervix cancer patients to decrease bowel dose and possible treatment-related toxicity.

Very accelerated partial breast irradiation in 1 or 2 days: Late toxicity and early oncological outcome of the GEC-ESTRO VAPBI cohort.

PURPOSE: To analyze late toxicity after very accelerated partial breast irradiation (VAPBI) for low-risk breast cancer. MATERIALS: Methods: In this retrospective, observational, international multicenter study (HDH F20220713143949), patients with low-risk breast cancer underwent lumpectomy + vAPBI (high-dose rate multicatheter interstitial brachytherapy-MIBT). VAPBI was performed with 4(4x6.2 Gy/2d), 3(3x7.45 Gy/2d) or 1 fraction (1x16Gy or 1x18Gy/1d). Primary endpoint was late toxicity. Secondary endpoints were cumulative incidence of breast cancer local relapse (LR) and distant metastatic relapse (DMR) and specific (SS) and overall (OS) survivals. Prognostic factors for late toxicity were analyzed. RESULTS: From 01/2012 to 06/2022, 516 pts with early breast cancer were enrolled. Median follow-up was 44 months [95 %CI 39-46]. Median age was 71 years [40-100]. Median tumor size was 12 mm [1-35]. VAPBI delivered 1, 3 and 4 fractions for 205pts (39.7 %), 167pts (32.4 %) and 144pts (28 %) respectively. 221 late toxicity events were observed in 168pts (32.6 %) (Fibrosis, dyschromia, pain and telangiectasia). Grade 2 and 3 late toxicities were observed in 7.2 and 0.6 % respectively (no G4) with no difference between 1 and ≥ 2 treatment days. CTV > 50 cc (p = 0.007) and V150 > 40 % (p = 0.027) were prognostic factors for G ≥ 2 late toxicity. Four-year cumulative incidence rates of LR and DMR were 2 % [95 %CI 0-3] and 1 % [95 %CI 0-2] respectively. CONCLUSIONS: VAPBI based on 1 or ≥ 2 days of MIBT represents an attractive de-escalation of irradiation approach for low-risk breast cancer. Late toxicity profile appears acceptable while early oncological outcome shows encouraging local control. Longer follow-up is warranted in order to confirm these preliminary results.

Brachytherapy: The urologist opinion.

Prostate cancer remains a prevalent concern worldwide, necessitating continual advancements in treatment modalities. This abstract explores the role of brachytherapy as a viable and effective option in the management of prostate cancer. Brachytherapy involves the implantation of radioactive sources directly into the prostate, providing a localized dose of radiation. n recent studies and clinical trials, brachytherapy has demonstrated promising outcomes, particularly in terms of disease control and patient outcomes. The treatment's ability to deliver a concentrated intraprostatic dose, often in combination with external beam radiotherapy, has shown favorable results. Furthermore, brachytherapy's impact on disease-free survival and its potential in reducing urinary and bowel toxicity have been subjects of investigation. This abstract delves into the technical aspects, patient outcomes, and emerging trends in brachytherapy for prostate cancer. By examining the current literature and research findings, we aim to shed light on the evolving role of brachytherapy in the comprehensive management of prostate cancer, emphasizing its potential as a valuable therapeutic option.

Cost-benefit ratio of modern medical education using micro-costing: a model calculation using the example of an innovative breast brachytherapy workshop.

BACKGROUND AND PURPOSE: Radiation oncology is an essential component of therapeutic oncology and necessitates well-trained personnel. Multicatheter brachytherapy (MCBT) is one radiotherapeutic option for early-stage breast cancer treatment. However, specialized hands-on training for MCBT is not currently included in the curriculum for residents. A recently developed hands-on brachytherapy workshop has demonstrated promising results in enhancing knowledge and practical skills. Nevertheless, these simulation-based teaching formats necessitate more time and financial resources. Our analyses include computational models for the implementation and delivery of this workshop and can serve as a basis for similar educational initiatives. METHODS: This study aimed to assess the cost-effectiveness of a previously developed and evaluated breast brachytherapy simulation workshop. Using a micro-costing approach, we estimated costs at a detailed level by considering supplies, soft- and hardware, and personnel time for each task. This method also allows for a comprehensive evaluation of the costs associated with implementing new medical techniques. The workshop costs were divided into two categories: development and workshop execution. The cost analysis was conducted on a per-participant basis, and the impact on knowledge improvement was measured using a questionnaire. RESULTS: The total workshop costs were determined by considering the initial workshop setup expenses including the development and conceptualization of the course with all involved collaborators, as well as the costs incurred for each individual course. The workshop was found to be financially efficient, with a per-participant cost of €â€¯39, considering the industrial sponsorship provided for brachytherapy equipment. In addition, we assessed the workshop's efficacy by analyzing participant feedback using Likert scale evaluations. The findings indicated a notable enhancement in both theoretical and practical skills among the participants. Moreover, the cost-to-benefit ratio (CBFR) analysis demonstrated a CBFR of €â€¯13.53 for each Likert point increment. CONCLUSION: The hands-on brachytherapy workshop proved to be a valuable and approximately cost-effective educational program, leading to a significant enhancement in the knowledge and skills of the participants. Without the support of industrial sponsorship, the costs would have been unattainable.

Brachytherapy Workflow Practices: Analysis of Different Workflow Scenarios in Patients With Cervical Cancer and Impact on IGBT Implementation-An IAEA Study.

PURPOSE: The workflow of brachytherapy (BT) is an essential aspect of treatment to consider in image-guided brachytherapy (IGBT). It has an overarching effect influencing patient throughput and the number of cancer treatments that can be performed as it occupies equipment, space, and personnel. There is limited research addressing this issue. Under the International Atomic Energy Agency's Coordinated Research Activity titled IGBT for cervix cancer: An implementation study, our study analyzes various scenarios in the clinical workflow of BT delivery for cervical cancer. It aims to determine the extent to which these scenarios allow the routine implementation of IGBT. With this information, current barriers and individualized adaptations to efficient workflows can be identified to enhance the global application of IGBT, leading to better cervical cancer treatment. MATERIALS AND METHODS: A web-based poll of questions regarding practices in BT workflow was presented to 62 participants from low-, lower middle-, upper middle-, and high-income countries (19 countries). RESULTS: This study highlighted diversity in BT practices across countries, income levels, and regions. It identified variations in workflow, patient throughput, and resource availability, which can have implications for the efficiency and quality of BT treatments. Scenario A, utilizing multiple locations for the steps of the BT procedure, was the most commonly used. The availability of resources, such as imaging devices and trained personnel, varied among the participating centers and remained challenging for IGBT implementation and sustainability. CONCLUSION: The design of the BT facility plays a vital role in improving efficiency, with a dedicated BT suite contributing to an efficient workflow but limiting patient throughput, especially for high-volume centers. Although IGBT is effective, its implementation requires consideration of various logistical challenges and should be individualized.

Impact of the COVID-19 pandemic on brachytherapy and cancer patient outcomes: A systematic review.

PURPOSE/OBJECTIVE(S): To assess the impact of the COVID-19 pandemic on the use of brachytherapy in patients with gynecologic and prostate cancers including treatment delays, increased burden of mortality, and associated clinical outcomes. MATERIALS/METHODS: A comprehensive search of PubMed, Cochrane Library, CINAHL, Scopus, and Web of Science was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Databases were searched for studies published through September 2023 using MeSH terms and keywords related to "COVID and brachytherapy." Inclusion criteria included all studies reporting on the impact of COVID-19 on treatment delay, treatment omission, recurrence rates, and clinical outcomes in patients requiring brachytherapy for prostate or gynecologic cancers from December 2019 to September 2023. Data were extracted by two independent reviewers (LH, IV). RESULTS: Of the 292 screened records, 10 studies (9 retrospective, 1 prospective single-arm exploratory noninferiority) were included. Hypofractioned regimens were the preferred approach in radiation treatment (RT) centers, with 6 of 10 studies noting shift towards hypofractionation. For cervical cancer, intracavitary brachytherapy was limited to 3-4 fractions, reducing personnel and patient exposure. Treatment delays influenced by COVID-19 ranged between 19% and 53% and treatment omissions ranged between 2% and 28%. These disruptions arose from factors such as patient fear of contracting COVID-19, COVID-19 infection, barriers to accessing care, and operating room closures. Three studies reported on a single-application (SA) rather than a multiple application (MA) approach for cervical cancer. They reported excellent local control, shorter overall treatment time at the expense of higher grade ≥2 vaginal, genitourinary, and gastrointestinal events. For cervical cancer patients, overall treatment time (OTT) was significantly impacted by COVID-19 as reported by 2 studies from India. OTT > 60 days occurred in 40-53% of patients. CONCLUSION: This is the first systematic review to assess the impact of the COVID-19 pandemic on brachytherapy in patients with gynecologic and prostate cancers. Although many expert consensus recommendations have been published during the pandemic regarding radiation therapy, few studies evaluated its clinical impact on brachytherapy delivery and patient outcomes. The COVID-19 pandemic resulted in treatment delays, omissions in brachytherapy, and further adoption of hypofractionated regimens. Early results demonstrate that despite increased toxicities, local control rates with hypofractionated treatment are similar to standard fractionation. The impact of the pandemic on gynecologic and prostate cancers is yet to be determined as well as the long-term outcomes on patients treated during the lockdown period.