Brachytherapy最新文献

{"title":"GSOR09 Presentation Time: 5:40 PM","authors":"Ramez Kouzy MD,&nbsp;Michael Rooney MD,&nbsp;Osama Mohamad MD, PhD,&nbsp;Christopher Weil MD,&nbsp;Lilie Lin MD,&nbsp;Anuja Jhingran MD,&nbsp;Patricia Eifel MD,&nbsp;Melissa Joyner MD, MBA,&nbsp;Lauren Colbert MD MSCR,&nbsp;Ann Klopp MD, PhD","doi":"10.1016/j.brachy.2024.08.055","DOIUrl":"10.1016/j.brachy.2024.08.055","url":null,"abstract":"<div><h3>Purpose</h3><div>The utilization of artificial intelligence in analyzing patient discussions on online platforms can uncover valuable experiential data that are often overlooked in structured surveys. Sentiment analysis, a branch of natural language processing (NLP), interprets and classifies emotions within text, offering insights into patient sentiments as positive, negative, or neutral. This study aimed to apply AI techniques to analyze the sentiments of posts on a cervical cancer-related online forum, specifically focusing on discussions related to brachytherapy.</div></div><div><h3>Materials/Methods</h3><div>Utilizing a Reddit Application Programing Interface, we extracted posts and comments from the subreddit r/cervicalcancer, focusing on discussions about brachytherapy between November 2020 and January 2024. We then processed the data in multiple steps including cleaning, lowercasing, removing illegible text, and tokenization. We analyzed the entries using RoBERTa (Robustly Optimized Bidirectional Encoder Representations from Transformers Pretraining Approach), a sophisticated pre-trained deep learning model, to refine and categorize sentiments. The model assessed the probabilities of the posts being positive, negative, or neutral. We further evaluated and categorized posts using pre-defined keyword tagging to uncover dominant topics within the conversations. These topics were modeled based on recently published literature related to the experiences of patients undergoing cervical brachytherapy.</div></div><div><h3>Results</h3><div>The analysis encompassed 879 out of 1,073 unique textual entries. Of these, overall sentiments were categorized as 40.1% positive, 30.1% negative, and 29.8% neutral. A specific focus on 'Bowel Domain’ discussions revealed a predominance of negative sentiments (51.2%)—the highest across all topics. Similarly, 'Urinary Domain' (46.8%), 'Fatigue' (42.4%), 'Anesthesia' (41.4%), and 'Pain' (43.4%) discussions largely reflected negative sentiments. In contrast, 'Physical Therapy' and 'Survivorship' discussions were predominantly positive, with 51.2% and 45.5% of posts, respectively. The sentiments on 'Sex' and 'Mental Health' related topics displayed a more balanced distribution between positive and negative perspectives.</div></div><div><h3>Conclusion</h3><div>This study demonstrates the value of using advanced AI models, such as sentiment analysis, to easily understand online patient discussions. These tools can bridge the gap between clinical insights and patient experiences, enhancing the feedback loop into clinical decisions, consent discussions, and patient education. Further research into the use of such models is necessary to fully leverage the insights they provide.</div></div>","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":"23 6","pages":"Page S46"},"PeriodicalIF":1.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MSOR08 Presentation Time: 8:35 AM","authors":"Emily MacDuffie MD ,&nbsp;Joy Ogunmuyiwa MD ,&nbsp;Michael LeCompte MD ,&nbsp;Kelsey Corrigan MD ,&nbsp;Abhishek Kumar MD ,&nbsp;Mustafa Basree DO ,&nbsp;Amishi Bajaj MD ,&nbsp;Andrew Farach MD ,&nbsp;Jenna Kahn MD ,&nbsp;Mitchell Kamrava MD ,&nbsp;Idalid Franco MD, MPH","doi":"10.1016/j.brachy.2024.08.070","DOIUrl":"10.1016/j.brachy.2024.08.070","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Purpose&lt;/h3&gt;&lt;div&gt;The Association of Residents in Radiation Oncology (ARRO) annual survey aims to better understand graduating radiation oncology (RO) residents’ perceptions of their training programs and readiness to enter practice. Residents graduating from US training institutions between 2020-2023 were asked about their confidence in performing brachytherapy (BT) by the completion of their residency program.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Materials and Methods&lt;/h3&gt;&lt;div&gt;Postgraduate year five RO residents were emailed a 50-56 question survey in May of their graduating year. Questions regarding brachytherapy asked respondents to describe their level of training and degree of comfort to practice high-dose rate (HDR) intracavitary and interstitial gynecological BT as well as HDR and low-dose rate (LDR) prostate brachytherapy after graduation. They were also asked to rate their satisfaction with various aspects of their training program. Responses were analyzed and compared. Differences between groups were analyzed using descriptive statistics and chi-square analyses. Ordinal variables were compared using the Kruskal-Wallis H test.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;The average response rate was 87.0% (77.8%-94.2%) and the total number of responses collected was 655. Confidence in delivering HDR interstitial and intracavitary gynecological BT rated as sufficient or adequate was 73.4% and 92.7%, respectively, while no or minimal training was 4.7% and &lt;1%, respectively (Figure 1). Sufficient or adequate confidence in practicing HDR and LDR prostate brachytherapy was 40.9% and 43.5%, respectively, while no or minimal training was 42.1% and 29.9%, respectively. Confidence did not differ across survey years for any type of BT. Increased comfort in delivery of interstitial gynecological BT was associated with respondents’ satisfaction with treatment plan evaluation training (p&lt;0.001), overall program training (p&lt;0.001), clinical didactics (p&lt;0.001), and faculty teaching (p&lt;0.001). Intracavitary gynecological BT confidence was associated with residency size (p&lt;0.001) and satisfaction with treatment plan evaluation training (p=0.001). Confidence in LDR prostate BT delivery was associated with satisfaction in treatment plan evaluation training (p&lt;0.001) and residency size (p=0.001). There were no associations between HDR prostate BT comfort and program features or resident satisfaction.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Conclusions&lt;/h3&gt;&lt;div&gt;Over three-quarters of RO residents graduating from 2020-2023 reported at least adequate training and comfort in performing gynecological BT. However, fewer than half of residents reported adequate training in prostate BT and a similar proportion reported little or no training at all during their residency, suggesting a potential training gap in prostate BT for US residents. Several factors were associated with increased confidence in these procedures; most notably the level of resident-reported satisfaction in th","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":"23 6","pages":"Page S54"},"PeriodicalIF":1.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MSOR09 Presentation Time: 8:40 AM","authors":"Kristin Hsieh MD ,&nbsp;Catherine Yu BA ,&nbsp;Drishti Panse MD ,&nbsp;Juliana Runnels MD ,&nbsp;Anthony Nehlsen MD ,&nbsp;Lucas Resende Salgado MD ,&nbsp;Jared P. Rowley MD ,&nbsp;Kunal K. Sindhu MD","doi":"10.1016/j.brachy.2024.08.071","DOIUrl":"10.1016/j.brachy.2024.08.071","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Purpose&lt;/h3&gt;&lt;div&gt;Brachytherapy is an essential treatment modality utilized in the management of several malignancies. However, its usage has been declining in the United States, which may be due, in part, to insufficient brachytherapy training for radiation oncology residents. The 1-year, post-residency brachytherapy fellowship has been offered to those interested in gaining additional training in brachytherapy procedures. The characteristics of individuals who choose to pursue this fellowship after graduating from US radiation oncology residency programs, however, are not well understood. In this study, we sought to better understand the characteristics and job outcomes of this cohort of individuals in order to provide further guidance to current US radiation oncology residents who are considering this fellowship.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Materials and Methods&lt;/h3&gt;&lt;div&gt;We created a comprehensive database of individuals who completed an Accreditation Council for Graduate Medical Education (ACGME)-accredited radiation oncology residency training program in the US between 2015 and 2022 and subsequently completed a radiation oncology fellowship. We utilized information from multiple publicly available sources in building this database, including residency/fellow training program websites, hospital/institutional websites, Doximity, LinkedIn, and the National Plan and Provider Enumeration System National Provider Identifier Registry.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;We identified 78 individuals who completed a radiation oncology fellowship during the time period analyzed, of whom 14 (17.9%) completed brachytherapy-focused fellowships (13 individuals completed dedicated brachytherapy fellowships, and 1 brachytherapy and stereotactic body radiation therapy fellowship) at five different institutions. Nine individuals (64.3%) were men and five (35.7%) were women, and 11 individuals (78.6%) trained at the same two institutions for fellowship. Four individuals graduated from large-sized residency programs (≥4 graduates per year), 6 from medium-sized programs (1.5-4 graduates per year), and 4 from small-sized programs (≤1.5 graduates per year). 5 individuals completed residency between 2015 and 2016, 4 between 2017 and 2018, 2 between 2019 and 2020, and 3 between 2021 and 2022. We identified the post-fellowship employment positions accepted by 13 of the 14 fellows (92.9%), While all thirteen currently work as radiation oncologists, only 9 (64.3%) have brachytherapy listed as an area of focus or clinical expertise on their employment websites. 10 individuals (71.4%) practice in academic settings, while 3 (21.4%) practice in non-academic settings. 11 individuals (78.6%) have remained in the same job since graduating from fellowship, while 2 (14.3%) have changed jobs at least once. 3 individuals (23.1%) accepted their first clinical employment position at the same institution from which they graduated from fellowship.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Conclusions&lt;/h3","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":"23 6","pages":"Page S55"},"PeriodicalIF":1.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MSOR03 Presentation Time: 8:10 AM","authors":"Mustafa Al Balushi MD FRCPC,&nbsp;Martin T. King MD PhD,&nbsp;Joel E. Goldberg MD MPH,&nbsp;Simon G. Talbot MD,&nbsp;Kee-Young Shin MS,&nbsp;Yu-Hui Chen MS,&nbsp;Harvey J. Mamon MD PhD,&nbsp;Phillip M. Devlin MD","doi":"10.1016/j.brachy.2024.08.066","DOIUrl":"10.1016/j.brachy.2024.08.066","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Purpose&lt;/h3&gt;&lt;div&gt;Despite advances in surgical techniques and multimodality therapy for anal canal and rectal cancers, local recurrence and unresectable disease remain a significant challenge, often associated with poor quality of life. It is not clear how best to address this entity in the absence of large prospective randomized trials. The aim of this study was to retrospectively evaluate the outcomes and toxicities of pelvic low dose rate brachytherapy (LDR) combined with surgical resection in patients with unresectable and locally recurrent anorectal cancers.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Materials and Methods&lt;/h3&gt;&lt;div&gt;Following IRB approval, patients with biopsy-proven anorectal cancers who underwent LDR during surgery for unresectable or locally recurrent anorectal cancers from 2004 to 2022 were included. Patients who had LDR for recurrent gynecological or genitourinary cancers were excluded. For all patients, the intent of surgery was complete resection of all visible disease. This was followed by LDR, either in the surgical bed for recurrent cancers or the site of microscopically positive margins for the unresectable patients. Following LDR mesh fixation with sutures, an omental flap was draped over the site of LDR to prevent seed migration and to minimize dose to organs at risk. Toxicity grading was done using the Common Terminology Criteria for Adverse Events (CTCAE) Version 5.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;Out of 29 eligible patients, 20 underwent Iodine-125 LDR, and 9 received Cesium-131 LDR with an average of 73.8 sources used per patient. The primary site was colorectal in 79.3% and anal canal in 20.7%. 27 (93.1%) of the patients had pelvic only disease at the time of LDR and surgery. 21 (72.4%) patients had at least 1 surgery prior to the implant prior to the implant, whereas 8 (27.6%) patients had no surgery prior to the implant. Brachytherapy was offered at recurrence in 23 patients (79.3%) and in 6 (20.7%) patients who were considered unresectable initially. In those with recurrences, 20 (87.0%) had LDR offered during their first recurrence and the rest were offered LDR at subsequent recurrences. Chemotherapy was offered at first recurrence in 21 (91.3%) patients. No Grade 4 or 5 toxicities were reported. The most common adverse event seen was neuralgia in 12 (41.4%) patients with 2 of those developing Grade 3 neuralgia. The rate of Grade 2 gastrointestinal fistula was 5 (17.2%) and Grade 2 urinary fistula was 3 (10.3%). All of the patients who developed fistulas were diverted at the time of surgery and LDR or before, and did not require additional invasive interventions. The 12 month and 24 month local progression free survival were 55.4% (95% CI: 34.9-71.8) and 41.7% (95% CI: 22.3 - 60.1), respectively. The 12 month and 24 month progression free survival were 38.4% (95% CI: 20.7-55.9) and 25.6% (95% CI: 10.9-43.3), respectively. The 12 month and 24 month overall survival rates were 88.7% (95% CI: 69.0-96.2) and 70.6% (95%","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":"23 6","pages":"Pages S51-S52"},"PeriodicalIF":1.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thursday, July 11, 20245:00 PM - 6:00 PMMSOR1 Presentation Time: 5:00 PM","authors":"Aaron Silvus MS,&nbsp;Ethan Memming BS,&nbsp;Thomas R. Mazur PhD,&nbsp;Liyun Chen PhD,&nbsp;Marlene Campos Guerrero BS,&nbsp;Jacqueline E. Zoberi PhD,&nbsp;Jessika Contreras MD,&nbsp;Stephanie Markovina MD, PhD,&nbsp;Michael B. Altman PhD","doi":"10.1016/j.brachy.2024.08.035","DOIUrl":"10.1016/j.brachy.2024.08.035","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Purpose&lt;/h3&gt;&lt;div&gt;HDR brachytherapy is an integral part of radiation therapy and is used jointly with EBRT in the treatment of numerous cancers including cervical cancer. For targets jointly treated with HDR and EBRT, ICRU 89 recommends the use of an EQD2 assessment on the accumulated dose between EBRT and brachytherapy fractions, assuming equivalent RBE between EBRT and HDR. Recent studies have shown that RBE can vary with photon energy, however, whether these differences in RBE translate to different biologic effects in cervical cancer, among others, have yet to be well studied. The goal of this study is to investigate biological endpoints in cervical cancer cell lines for an HDR remote afterloader and a clinical linear accelerator.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Materials and Methods&lt;/h3&gt;&lt;div&gt;We developed a portable 3D printed platform allowing for the joint study of clinical HDR brachytherapy (Bravos, Varian Medical Systems, Palo Alto, CA) and clinical EBRT (Edge, Varian Medical Systems, Palo Alto, CA). Gamma-H2AX (gH2AX) foci formation and clonogenic survival assays were performed in an effort to characterize the biological effects of clinical irradiators commonly used to treat cervical cancer in three cervical cancer cell lines: HT3, CasKi, and SW756. Cells were irradiated using the 3D printed platform for both HDR and EBRT irradiations, as the design can accommodate cells plated in a standard sized tissue culture plate which can be irradiated by up to 14 HDR source channels or by clinical EBRT irradiators. GH2AX foci were quantified to estimate DNA double strand breaks at two post irradiation time points: 30 minutes for early damage and 24 hours as a surrogate for DNA repair capacity. Clonogenic survival was determined 10-14 days after RT (n &gt; 50 cells). For HDR irradiations, a dose of 4 Gy (gH2AX) or 6 Gy (clonogenic survival) was delivered at a source-to-cell distance (SCD) of 0.4 cm and 1 cm giving dose rates of 30-50 Gy/min and 3-5 Gy/min, respectively. EBRT irradiations uniformly delivered 4 Gy (gH2AX) or 6 Gy (clonogenic survival) to a 96-well tissue culture plate with a single anterior/posterior 15 × 15 cm&lt;sup&gt;2&lt;/sup&gt; field at a 100 cm source-to-axis distance. Statistical analysis was performed using the one way ANOVA statistical test (p &lt; 0.05) with Tukey's multiple comparisons test and the Mann-Whitney U test (p &lt; 0.05) for the gH2AX assay and the clonogenic survival assay, respectively.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;At 30 minutes, all irradiated groups had significantly more gH2AX foci than their respective control groups. There were no statistically significant differences in this cohort between modalities for HT3 at either 30 minutes or 24 hours. For CasKi and SW756, EBRT had significantly fewer gH2AX foci than HDR at 0.4 cm SCD and 1 cm SCD. In terms of clonogenic survival for HT3, the EBRT treated cells had a significantly higher survival fraction than those treated with HDR at 0.4 cm SCD but not 1 cm SCD. CasKi ","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":"23 6","pages":"Page S35"},"PeriodicalIF":1.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MSOR2 Presentation Time: 5:05 PM","authors":"Mahdokht Akbari Taemeh PhD Candidate ,&nbsp;Théophraste Lescot M.Sc. ,&nbsp;Marc-André Fortin Ing., Ph.D.","doi":"10.1016/j.brachy.2024.08.036","DOIUrl":"10.1016/j.brachy.2024.08.036","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Purpose&lt;/h3&gt;&lt;div&gt;Personalized 3D-printed brachytherapy (BT) implants and advanced dose painting methods for better-targeting tumor geometry, could improve BT outcomes&lt;sup&gt;1&lt;/sup&gt;. One challenge in this approach is the necessity of measuring the dose profile for each device, before implantation. Polymer gel dosimeters (PGD) could meet the dosimetry challenges of personalized BT devices. However, PGDs have been mainly used in external beam therapy applications and at high-energy photons; by comparison for low-dose-rate (LDR) BT, low-energy photons (LEP) raise issues of water equivalency, energy response&lt;sup&gt;2a&lt;/sup&gt; and longer exposure times. In this study, a homogeneous PGD formulation based on methacrylic acid (MAA, the reactive monomer) was optimized to meet these challenges. A dosimetry assessment methodology was elaborated for LDR-BT devices, involving the measurement of gel response to LEP using MRI (3 magnetic fields: 1, 1.5, 3T) and experimental dose profiles were generated in PGDs upon exposure to 3D-printed plaques containing &lt;sup&gt;125&lt;/sup&gt;I seeds and numerically plotted in 3D.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Materials and Methods&lt;/h3&gt;&lt;div&gt;&lt;em&gt;Single Seed Experiment (SSE):&lt;/em&gt; a MAGIC-f gel formulation&lt;sup&gt;3&lt;/sup&gt; was optimized by adding 0.75 %w/w paraformaldehyde (PF) as gelatin crosslinker. Gelatin and PF were dissolved in pure water and mixed at 45°C. CopperII sulfate pentahydrate, L-ascorbic acid and MAA were added at 37°C. The solution was gelified in a glass container at 4°C overnight. Formed gels were exposed to a &lt;sup&gt;125&lt;/sup&gt;I seed (OncoSeed 6711, activity: 2.13 mCi; n=3) placed in a fixed glass tube for 54h at RT (Fig1a). The gels were MRI-scanned (&lt;em&gt;T&lt;sub&gt;2&lt;/sub&gt;&lt;/em&gt;-w) with 0.9 × 0.9 × 0.9 mm&lt;sup&gt;3&lt;/sup&gt; voxel size using 1T, 1.5T and 3T MRI (TR/TE= 3585(1T)-4350(1.5T)-5410(3T)/22-352ms). &lt;em&gt;T&lt;sub&gt;2&lt;/sub&gt;&lt;/em&gt; (=1/ &lt;em&gt;R&lt;sub&gt;2&lt;/sub&gt;&lt;/em&gt;) maps were generated across the vial axial plane. The TOPAS Monte Carlo (MC) code toolkit was used to calculate the absolute dose deposited in the gel with a similar seed model and the &lt;em&gt;R&lt;sub&gt;2&lt;/sub&gt;&lt;/em&gt;-dose calibration curve was plotted. Gel water equivalency was assessed by MC, comparing the percentage depth dose (PDD) delivered to water and gel phantoms when exposed to &lt;sup&gt;125&lt;/sup&gt;I seeds. Gel thermal and temporal stability were assessed up to 70 °C and over 7 days, respectively. &lt;em&gt;Dose profile visualization:&lt;/em&gt; A two-part box and a plaque with 3 holes (1 × 1.5 mm diam/depth) were 3D-printed (Apium P220 printer) in PEEK as the gel container and &lt;sup&gt;125&lt;/sup&gt;I seed holder, respectively (Fig1e). The gel was prepared (SSE protocol) and exposed to the plaque for 54h (avg. activity: 1.58 mCi; n=3) followed by 3T &lt;em&gt;T&lt;sub&gt;2&lt;/sub&gt;&lt;/em&gt;-w MRI scanning. The dose was visualized in 3D using the calibration curve and the Python code using Plotly Library.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;The results showed that MAGIC-f gel is water equivalent (gel/water PDD ∼1), thermally (up to 70 °C","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":"23 6","pages":"Pages S35-S36"},"PeriodicalIF":1.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Saturday, July 13, 202410:30 AM - 11:30 AMPPP01 Presentation Time: 10:30 AM","authors":"Frédéric Lacroix Ph.D ,&nbsp;Eric Poulin Ph.D. ,&nbsp;Cédric Bélanger Ph.D. ,&nbsp;Sylviane Aubin M.Sc. ,&nbsp;Eric Vigneault MD ,&nbsp;André-Guy Martin M.D. ,&nbsp;François Bachand M.D. ,&nbsp;Luc Beaulieu Ph.D. ,&nbsp;William Foster M.D.","doi":"10.1016/j.brachy.2024.08.093","DOIUrl":"10.1016/j.brachy.2024.08.093","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Purpose&lt;/h3&gt;&lt;div&gt;gMCO generated plans for HDR prostate brachytherapy have been shown to be superior to standard reference clinical plans in a blinded pairwise comparison[1]. The purpose of this work, a first-in-man trial, was to compare gMCO and reference plans in terms of planning time and plan quality for prostate HDR brachytherapy 15Gy boosts in a randomized clinical trial.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Materials and Methods&lt;/h3&gt;&lt;div&gt;The brachytherapy procedure was as follows: 1) Patient walk-in/installation/anaesthesia 2) Positioning/Catheter implantation under transrectal ultrasound (US) guidance 3) 3D US scan 4) Contouring/catheter reconstruction on Oncentra Prostate (Elekta, Veenendaal, Netherlands) 5) Planning 6) Treatment. Planning (step 5) was performed, after randomization, using either IPSA (Oncentra Prostate, Veenendaal, Netherlands) or gMCO (in-house platform). For gMCO planning, the contours and reconstructed catheters were exported to gMCO at step 4) and the resulting plan was imported on OCP at step 6). The planning times on IPSA or gMCO were recorded. Patients previously had a planning MR in order to identify the gross tumor volume (GTV, PIRADS 3 and above)and, if present, received a boost of 125% of the prescription dose. At the time of writing, 55 (of 60) patients have been accrued and treated on this trial. Of those, only 10 patients had no GTV. Dosimetric parameters (Prostate V100, V150, V200, GTV D90, Urethra D10, Rectum and Bladder V75 and D1cc) of gMCO and IPSA plans were compared (Student's T test) to determine if plan quality and planning times were statistically different.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;Figure 1 shows a) a boxplot of the the planning times (minutes), b) a boxplot of the GTV D90 coverage (Gy) and c) a histogram of the proportion of GTVs with more than 19, 19.5 and 20 Gy D90 coverage for gMCO and IPSA for the 55 accrued patients (29 gMCO and 26 IPSA). Figure 1 a) shows that the median planning time for clinical cases is roughly halved (p=0.0002) for gMCO (5.0 min) compared to IPSA (10.0 min) and b) shows a trend towards higher GTV D90s for gMCO planning compared to IPSA (p=0.26). The median GTV volume and standard deviation was 3.5 cc (4.2 cc std) for gMCO and 2.8 cc (2.3 cc std) for IPSA patients (p=0.21). Additionally, we found no learning curve effect in the planning using gMCO. No statistically significant differences were found between dosimetric parameters for the prostate V100, V150, D90, Bladder V75, Rectum V75 and Urethra D10. The prostate V200 was statistically higher for gMCO (p=0.048), possibly because of higher GTV D90 to the (19.8 Gy) compared to IPSA (19.3 Gy). Figure 1c) shows that a superior GTV D90 coverage can be obtained more consistently for gMCO as compared to IPSA at 19, 19.5 and 20 Gy.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Conclusion&lt;/h3&gt;&lt;div&gt;This work presents a first-in-man trial of GPU based multicriteria optimization in prostate HDR brachytherapy. The planning time was halved when using gM","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":"23 6","pages":"Pages S68-S69"},"PeriodicalIF":1.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PHSOR08 Presentation Time: 9:35 AM","authors":"Margaret Barker MS,&nbsp;Michael Campbell MS,&nbsp;Lisa Turner MS,&nbsp;Nisar Syed MD,&nbsp;Randy Wei MD, PhD,&nbsp;Peyman Kabolizadeh MD, PhD","doi":"10.1016/j.brachy.2024.08.082","DOIUrl":"10.1016/j.brachy.2024.08.082","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Purpose/Objectives&lt;/h3&gt;&lt;div&gt;Interstitial HDR brachytherapy to the prostate involves precise, localized delivery to targets with high dose gradients, sparing adjacent organs at risk (OAR). Due to the proximity of the rectum and bladder to the target, deviations in the template position or catheter with respect to patient anatomy can change dose to those structures. While utilizing plastic interstitial catheters allows the patient to receive hyperthermia therapy during their course of interstitial treatment, the plastic catheters were observed to show significant deflection when the metal stylets are removed for treatment. The flexion of the source path for this particular afterloader has been previously demonstrated to show significant deviation within rigid intracavitary devices. The purpose of this study is to assess the magnitude and deflection of the plastic catheters for prostate interstitial plans and determine whether using flexible wires of similar thickness to the source cable for visualization on pre-treatment imaging is suitable for reconstructing the actual treatment received.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Materials/Methods&lt;/h3&gt;&lt;div&gt;Pre-treatment CT images where the stylets were utilized for catheter visualization were registered to a subsequent CT scan with the metal stylets removed. The original treatment dwell positions and times were adjusted to the second CT to evaluate three-dimensional catheter displacement and dose distributions calculated for the bladder, rectum, urethra, and target. The plans were subsequently reconstructed on a pre-planning CT with flexible 20-gauge wires instead of metal stylets in order to determine their suitability as a surrogate for stylets.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;Absolute 3D displacement for all patients was 4.9 mm ± 3.0 mm (n = 1645 catheter dwell positions for all treatment plans and patients, mean ± SD, p&lt;0.001) comparing plans with the stylet in versus out. Absolute catheter deflection magnitude for interstitial treatments increased with the removal of the metal stylets with a difference of 1.07° ± 0.83° (n = 153 catheters for all treatment plans and patients, mean ± SD, p&lt;0.01). The plans utilizing flexible wire instead of stylets are observed to correlate with the plans with no stylets with absolute 3D displacement and angular deflection of 1.7 ± 1.1 mm and 0.36° ± 0.3° respectively (n = 67 catheters, mean ± SD, p&gt;0.2). There was an overall increase in bladder D2cc (p&lt;0.01) with the stylets utilized vs removed. Bladder D2cc, rectal D2cc, and urethra D0.1cc showed no appreciable difference between utilizing flexible wires for visualization and the plans without (p&gt;0.10). There is no appreciable difference in target coverage comparing the plan types (p&gt;0.5).&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Conclusions&lt;/h3&gt;&lt;div&gt;Catheter reconstruction in interstitial prostate treatments with CT imaging revealed significant changes in catheter positioning with respect to the OAR volumes once the st","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":"23 6","pages":"Pages S61-S62"},"PeriodicalIF":1.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PHSOR04 Presentation Time: 9:15 AM","authors":"Ioannis Androulakis PhD ,&nbsp;Myra van Laar BSc ,&nbsp;Jérémy Godart PhD ,&nbsp;Robin Straathof MSc ,&nbsp;Henrike Westerveld PhD, MD ,&nbsp;Remi Nout PhD, MD ,&nbsp;Mischa Hoogeman PhD ,&nbsp;Inger-Karine K. Kolkman-Deurloo PhD","doi":"10.1016/j.brachy.2024.08.078","DOIUrl":"10.1016/j.brachy.2024.08.078","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Purpose&lt;/h3&gt;&lt;div&gt;Afterloader integrated electromagnetic tracking (EMT) in pelvic high dose rate brachytherapy (HDR-BT) has shown sub-millimeter accuracy in detecting dwell positions in interstitial implants. However, larger residual errors were found when including dwell positions from gynaecological applicators [van Heerden &lt;em&gt;et. al&lt;/em&gt; (2021)]. The purpose of this study is to analyze EMT measurements in the Venezia™ intracavitary gynaecological applicator (Elekta AB, Stockholm, Sweden), and assess their agreement with manufacturer-specified dwell positions in the treatment planning software (TPS).&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Materials and Methods&lt;/h3&gt;&lt;div&gt;Measurements with the afterloader integrated EMT system (Elekta AB, Stockholm, Sweden) were performed on 8 applicators. We included two different applicator configurations: a small configuration consisting of 22 mm/60° ovoids (OVs) with a 40 mm/30° intrauterine tandem (IU), and a large configuration consisting of 26 mm/60° OVs with a 70 mm/30° IU. For each of the two configurations, 4 applicators were included: 2 old applicators being phased out of clinical use, and 2 new applicators before clinical introduction. Dwell positions with an interval of 5 mm were measured along the full length of each of the three applicator channels. Measurements in each applicator were repeated 5 times to determine maximum measurement deviation, including repositioning of the applicator and reconnecting to the transfer tubes. The measurements from the four distinct applicators within each configuration were compared to evaluate maximum inter-applicator deviation. Applicator configuration measurements were compared with manufacturer-specified dwell positions, as defined in the Oncentra-Brachy TPS (Elekta AB, Stockholm, Sweden). Manufacturer-specified dwell positions consist of centerline data for the IU and measured source position data for the OVs. In all comparisons, Euclidean distances (ED) between corresponding dwell positions after registration (Procrustes analysis) were used to determine deviation.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;Maximum intra-applicator measurement deviation was below 0.8 mm for all applicators. A maximum inter-applicator deviation of 1.3 mm was observed, invariant across configurations and irrespective of applicator age. Comparing the measured dwell positions to the manufacturer-specified dwell positions, EDs of up to 3.8 mm and 4.2 mm were found for the small and large configuration, respectively. The largest deviation between EMT measurements and manufacturer-specified dwell positions were found at the IU tip for both applicator configurations, see Fig. 1. For the straight part and curved part of the IU, maximum deviations were considerably lower at 2.1 mm and 1.9 mm, for the small and large applicator configuration respectively. In the OVs the maximum deviations were 2.5 mm and 2.4 mm, for the small and large applicator configuration respectively.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Conclusion","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":"23 6","pages":"Page S59"},"PeriodicalIF":1.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GSOR04 Presentation Time: 5:15 PM","authors":"Memory Fadziso Bvochora-Nsingo Masters in Medicine,&nbsp;Dawn Balang MD","doi":"10.1016/j.brachy.2024.08.050","DOIUrl":"10.1016/j.brachy.2024.08.050","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Purpose&lt;/h3&gt;&lt;div&gt;Cervical cancer remains the most prevalent cancer treated in Botswana. With only a single institution offering curative chemoradiation during the pandemic, brachytherapy cases serve as a proxy for all curative interventions.The study examines the consequences of the COVID-19 pandemic on the provision of brachytherapy for cervical cancer in Botswana, emphasizing the challenges posed by lockdowns and restrictions on both local and international travel. The impact of the COVID-19 pandemic on the continuity of brachytherapy could mirror disruptions faced by other cancer treatments due to regional lockdowns and centralized treatment modalities.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Materials and Methods&lt;/h3&gt;&lt;div&gt;A longitudinal analysis of brachytherapy cases from 2018 to 2023 was conducted, with a particular focus on the trend changes coinciding with the COVID-19 pandemic. Data was collated from hospital records, maintenance logs for medical equipment, national cancer registries, and pandemic response documentation. The analysis explored the correlation between pandemic-related restrictions and the accessibility of brachytherapy services.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;Of the 2499 brachytherapy insertions done in the six years between 2018 and 2023 only 110 insertions (4.5%) were done in 2020 and 238 (9.5%) in 2021, the peak COVID years. Fig 1 illustrates the pandemic's impact on brachytherapy services in Botswana.The one-way ANOVA conducted to compare the mean number of brachytherapy insertions before(2018 to 2019), during (2020 to 2021), and after (2022 to 2023) the pandemic yields an F-statistic of approximately 33.837 and a p-value of approximately 0.0087, suggesting that there is a statistically significant difference in the number of brachytherapy insertions among at least two of the three periods compared. The analysis highlights a severe reduction in brachytherapy treatments in 2020 and 2021. This period coincides with a gorvenrment lockdown beginning in April 2020, with subsequent regional lockdowns and quarantine of both healthcare workers and patients. There was a three-month breakdown of the single linear accelerator at the nation's primary cancer treatment center, attributable to the absence of engineers from South Africa who were unable to travel due to lockdowns. Additionally, the expiry of the Ir192 source, essential for brachytherapy and challenging to replace due to its short half-life of 174 days, led to a six-month cessation of services. This was compounded by regulatory complexities and the dependence on international engineers for both source replacement and equipment servicing.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Conclusion&lt;/h3&gt;&lt;div&gt;The COVID-19 pandemic significantly disrupted brachytherapy services for cervical cancer, reflective of broader oncological treatment challenges during this period. It exposed vulnerabilities in Botswana's cancer treatment infrastructure, particularly the risk associated with using a short-lived isotop","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":"23 6","pages":"Page S43"},"PeriodicalIF":1.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}