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Background: Electromagnetic Tracking (EMT) technology has been integrated in a prototype high-dose-rate brachytherapy (HDR-BT) afterloading device. Its potential for dwell position (DP) monitoring has earlier been demonstrated in prostate phantoms. However, its performance for prostate BT in the clinical setting remains to be assessed., Aim: Assess the reliability and value of EMT measurements in transrectal ultrasound-based (TRUS-based) and computed tomography-based (CT-based) prostate HDR-BT., Methods: EMT measurements were conducted on 20 patients undergoing dual-fraction prostate HDR-BT monotherapy. In each treatment fraction an individual TRUS-based or CT-based treatment plan was generated. The measurements were compared to DPs of manually reconstructed needles in those TRUS-based or CT-based treatment plans. An internal reference sensor was also placed in one needle to assess internal movement levels and its potential for movement correction., Results: For TRUS-based treatments, median Euclidean distances (ED) of 1.00 mm were observed between EMT measurements and manual DP determination. Reference sensor movement was minimal at a median of 0.18 mm. For DPs measured in the CT-room and treatment room, median EDs of 1.60 mm and 2.24 mm compared to CT-based DP determination respectively were observed, indicating the system's ability to detect changes in implant geometry over time and after patient repositioning. Median reference sensor movement of 0.97 mm was observed. Implementing reference sensor-based movement correction led to a significant but small decrease in ED for CT-based treatments., Conclusion: EMT is suitable for TRUS-based prostate HDR-BT quality assurance and error detection. While EMT can identify changes in implant geometry in CT-based prostate HDR-BT treatments, it showed lower accuracy in this setting., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background and Purpose: To investigate the trade-off between bone marrow sparing (BMS) and dose to organs at risk (OARs) for intensity modulated proton therapy (IMPT) for women with locally advanced cervical cancer (LACC)., Materials and Methods: Twenty LACC patients were retrospectively included. IMPT plans were created for each patient using automated treatment planning. These plans progressively reduced bone marrow mean doses by steps of 1 GyRBE, while constraining target coverage and conformality. The relation between bone marrow dose and bladder, small bowel, rectum, and sigmoid doses was evaluated., Results: A total of 140 IMPT plans were created. Plans without BMS had an average [range] bone marrow mean dose of 17.3 [14.7-21.6] Gy RBE  , which reduced to 12.0 [10.0-14.0] Gy RBE  with maximum BMS. The mean OAR dose [range] increased modestly for 1 Gy RBE  BMS: 0.2 [0.0 - 0.6] Gy RBE  for bladder, 0.3 [-0.2 - 0.7] Gy RBE  for rectum, 0.4 [0.1 - 0.8] Gy RBE  for small bowel, and 0.2 [-0.2 - 0.4] Gy RBE  for sigmoid. Moreover, for maximum BMS, mean OAR doses [range] escalated by 3.3 [0.1 - 6.7] Gy RBE  for bladder, 5.8 [1.8 - 12.4] Gy RBE  for rectum, 3.9 [1.6 - 5.9] Gy RBE  for small bowel, and 2.7 [0.6 - 5.9] Gy RBE  for sigmoid., Conclusion: Achieving 1 Gy RBE  BMS for IMPT is feasible for LACC patients with limited dosimetric impact on other OARs. While further bone marrow dose reduction is possible for some patients, it may increase OAR doses substantially for others. Hence, we recommend a personalized approach when introducing BMS into clinical IMPT treatment planning to carefully assess individual patient benefits and risks., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: The PORTEC-4a trial investigates molecular-integrated risk profile guided adjuvant treatment for endometrial cancer. The quality assurance programme included a dummy run for vaginal brachytherapy prior to site activation, and annual quality assurance to verify protocol adherence. Aims of this study were to evaluate vaginal brachytherapy quality and protocol adherence., Methods: For the dummy run, institutes were invited to create a brachytherapy plan on a provided CT-scan with the applicator in situ. For annual quality assurance, institutes provided data of one randomly selected brachytherapy case. A brachytherapy panel reviewed and scored the brachytherapy plans according to a checklist., Results: At the dummy run, 15 out of 21 (71.4%) institutes needed adjustments of delineation or planning. After adjustments, the mean dose at the vaginal apex (protocol: 100%; 7 Gy) decreased from 100.7% to 99.9% and range and standard deviation (SD) narrowed from 83.6-135.1 to 96.4-101.4 and 8.8 to 1.1, respectively. At annual quality assurance, 22 out of 27 (81.5%) cases had no or minor and 5 out of 27 (18.5%) major deviations. Most deviations were related to delineation, mean dose at the vaginal apex (98.0%, 74.7-114.2, SD 7.6) or reference volume length., Conclusions: Most feedback during the brachytherapy quality assurance procedure of the PORTEC-4a trial was related to delineation, dose at the vaginal apex and the reference volume length. Annual quality assurance is essential to promote protocol compliance, ensuring high quality vaginal brachytherapy in all participating institutes., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Addition of deep hyperthermia results in improved local control (LC) and overall survival (OS) compared to radiotherapy alone in patients with cervical carcinoma. Previously, we showed that the thermal dose of hyperthermia significantly correlates with LC and disease specific survival (DSS). Over the last decade, new radiation techniques were introduced resulting in improved LC., Aim: To validate the effect of thermal dose in a more recent cohort of patients treated with modern radiotherapy techniques, including image guided brachytherapy (IGBT)., Methods: We analyzed primary cervical carcinoma patients treated with a combination of radiotherapy and deep hyperthermia between 2005 and 2016 at our institute. Data on patient, tumor and treatment were collected including the thermal dose parameters TRISE and CEM43T90. Follow-up data on LC, disease free survival, DSS, OS as well as late toxicity data were collected. Data were analyzed using the Cox proportional hazard and Kaplan-Meier analyses., Results: 227 patients were included. In multivariate analysis, histology, FIGO stage, lymphadenopathy, TRISE, CEM43T90 and IGBT had a significant effect on LC. In the patients treated with IGBT, the thermal dose parameter TRISE remained to have a significant effect on LC in univariate analysis., Conclusions: The positive association between thermal dose and clinical outcome is replicated in an independent, recent cohort of cervical carcinoma patients. Importantly, in patients receiving IGBT, the effect of thermal dose on clinical outcome is still observed., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Purpose: Library-of-plans ART is used to manage daily anatomy changes in locally advanced cervical cancer. In our institute, the library contains 2 VMAT plans for patients with large cervix-uterus motion. Increasing this number could be beneficial for tissue sparing, but is burdensome while the dosimetric gain is yet unclear. This study's aim is to determine the optimal number of plans at an individual patient level., Material and Methods: Data of 14 treated patients were analyzed. Plan libraries were created containing 1-4 VMAT plans. Pre-treatment extent of uterus motion was defined by the 99th percentile of the Hausdorff distance (HD99). For dosimetric evaluations, OARs were contoured in daily CBCT scans, plan selection was simulated, and the V 45Gy and V 40Gy parameters were recorded., Results: Moderate to strong correlations were found between HD99 and the volume of spared OARs. All patients benefitted from adding a 2nd plan, as is the clinical practice. For patients with a HD99 between 30 and 50mm, a 3-plan library reduced the composite V 40Gy with 11-21ml compared to a 2-plan library., Conclusion: Patients with large uterus motion (HD99>30mm) would benefit from an extension of the plan library to 3. HD99 is an easy-to-implement criteria to select those patients pre-treatment., (Copyright © 2017 Elsevier B.V. All rights reserved.)