Brachytherapy最新文献

{"title":"PHSOR08 Presentation Time: 9:35 AM","authors":"Margaret Barker MS, Michael Campbell MS, Lisa Turner MS, Nisar Syed MD, Randy Wei MD, PhD, Peyman Kabolizadeh MD, PhD","doi":"10.1016/j.brachy.2024.08.082","DOIUrl":"10.1016/j.brachy.2024.08.082","url":null,"abstract":"<div><h3>Purpose/Objectives</h3><div>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.</div></div><div><h3>Materials/Methods</h3><div>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.</div></div><div><h3>Results</h3><div>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<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<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>0.2). There was an overall increase in bladder D2cc (p<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>0.10). There is no appreciable difference in target coverage comparing the plan types (p>0.5).</div></div><div><h3>Conclusions</h3><div>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":null,"pages":null},"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 , Myra van Laar BSc , Jérémy Godart PhD , Robin Straathof MSc , Henrike Westerveld PhD, MD , Remi Nout PhD, MD , Mischa Hoogeman PhD , 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":"<div><h3>Purpose</h3><div>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 <em>et. al</em> (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).</div></div><div><h3>Materials and Methods</h3><div>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.</div></div><div><h3>Results</h3><div>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.</div></div><div><h3>Conclusion","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":null,"pages":null},"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":"Thursday, July 11, 20245:00 PM - 6:00 PMMSOR1 Presentation Time: 5:00 PM","authors":"Aaron Silvus MS, Ethan Memming BS, Thomas R. Mazur PhD, Liyun Chen PhD, Marlene Campos Guerrero BS, Jacqueline E. Zoberi PhD, Jessika Contreras MD, Stephanie Markovina MD, PhD, Michael B. Altman PhD","doi":"10.1016/j.brachy.2024.08.035","DOIUrl":"10.1016/j.brachy.2024.08.035","url":null,"abstract":"<div><h3>Purpose</h3><div>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.</div></div><div><h3>Materials and Methods</h3><div>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 > 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<sup>2</sup> field at a 100 cm source-to-axis distance. Statistical analysis was performed using the one way ANOVA statistical test (p < 0.05) with Tukey's multiple comparisons test and the Mann-Whitney U test (p < 0.05) for the gH2AX assay and the clonogenic survival assay, respectively.</div></div><div><h3>Results</h3><div>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":null,"pages":null},"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 , Théophraste Lescot M.Sc. , 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":"<div><h3>Purpose</h3><div>Personalized 3D-printed brachytherapy (BT) implants and advanced dose painting methods for better-targeting tumor geometry, could improve BT outcomes<sup>1</sup>. 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<sup>2a</sup> 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 <sup>125</sup>I seeds and numerically plotted in 3D.</div></div><div><h3>Materials and Methods</h3><div><em>Single Seed Experiment (SSE):</em> a MAGIC-f gel formulation<sup>3</sup> 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 <sup>125</sup>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 (<em>T<sub>2</sub></em>-w) with 0.9 × 0.9 × 0.9 mm<sup>3</sup> voxel size using 1T, 1.5T and 3T MRI (TR/TE= 3585(1T)-4350(1.5T)-5410(3T)/22-352ms). <em>T<sub>2</sub></em> (=1/ <em>R<sub>2</sub></em>) 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 <em>R<sub>2</sub></em>-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 <sup>125</sup>I seeds. Gel thermal and temporal stability were assessed up to 70 °C and over 7 days, respectively. <em>Dose profile visualization:</em> 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 <sup>125</sup>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 <em>T<sub>2</sub></em>-w MRI scanning. The dose was visualized in 3D using the calibration curve and the Python code using Plotly Library.</div></div><div><h3>Results</h3><div>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":null,"pages":null},"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 , Eric Poulin Ph.D. , Cédric Bélanger Ph.D. , Sylviane Aubin M.Sc. , Eric Vigneault MD , André-Guy Martin M.D. , François Bachand M.D. , Luc Beaulieu Ph.D. , William Foster M.D.","doi":"10.1016/j.brachy.2024.08.093","DOIUrl":"10.1016/j.brachy.2024.08.093","url":null,"abstract":"<div><h3>Purpose</h3><div>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.</div></div><div><h3>Materials and Methods</h3><div>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.</div></div><div><h3>Results</h3><div>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.</div></div><div><h3>Conclusion</h3><div>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":null,"pages":null},"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":"PPP04 Presentation Time: 10:57 AM","authors":"Iosif Strouthos MD, PhD , Efstratios Karagiannis MD, PhD , Nicole Zamba MD , Dimitris Sokratous MD , Artemis Christodoulou MD , Georgios Antorkas MSc , Yiannis Roussakis PhD, MSc , Alexis Vrachimis MD, PhD , Constantinos Zamboglou MD, PhD , Konstantinos Ferentinos MD, PhD","doi":"10.1016/j.brachy.2024.08.012","DOIUrl":"10.1016/j.brachy.2024.08.012","url":null,"abstract":"<div><h3>Purpose</h3><div>To report acute and early late toxicity and impact on early quality of life (QoL) of a patient cohort staged with 18F-PSMA-PET/CT, treated with a combination of prostate high dose-rate brachytherapy (HDR-BT) and prostate/seminal vesicle external beam radiation therapy (EBRT) for intermediate and high-risk prostate cancer in a phase II prospective trial (NCT05003752).</div></div><div><h3>Materials and Methods</h3><div>In this prospective phase II trial, a total of 41 patients with intermediate (IR), high (HR) and very high risk (VHR) prostate cancer, were recruited to receive a combination of hypofractionated EBRT to the prostate/seminal vesicles of 36 Gy (12 fractions of 3 Gy each) delivered in consecutive days, followed by single fraction real time HDR-BT of 14 Gy. Patients also received short-term (3-6 months) or long-term (>6 months) androgen deprivation therapy (ADT). All patients were both conventionally staged with prostate multi-parametric MRI (mpMRI), abdomen/pelvis CT and bone scintigraphy, with additional PSMA-PET/CT prior to their study inclusion. Acute, as well as early late genito-urinary (GU) and gastro-intestinal (GI) toxicity was assessed according to Radiation Therapy Oncology Group (RTOG) and European Organisation for Research and Treatment of Cancer (EORTC) questionnaires. Patient QoL was evaluated through Expanded Prostate Cancer Index Composite for Clinical Practice (EPIC-CP) questionnaires. Erectile function was assessed by International Index for Erectile Function -5 (IIEF-5) questionnaire.</div></div><div><h3>Results</h3><div>Fourty-one patients (NCCN 48.8% UIR, 43.9% HR and 7.3% VHR) completed treatment and reached at least 14 months of follow-up (FU) at the time of the current analysis. Median FU was 20 months (IQ range 14-28). Median age was 72 years, median PSA before treatment was 11.0 ng/mL (5.0-28.3) and median volume of the prostate was 36.5 cc (14.9-68.2). Short-term ADT was administered to 43.9% of patients whereas 48.8% received long-term ADT, the rest of the patients did not receive hormonal therapy. No severe (i.e. Grade 2-4) acute events were recorded. The most common acute GU symptoms were nocturia and dysuria (29% and 20% respectively), whereas the most common acute GI events were increased bowel movements and pain during defecation (10% and 5% respectively). A significant decline from baseline compared to 3 months post treatment was observed both in hormonal and sexual domains, with high severity exhibited as a worsening from 12% to 38% and from 0% to 5%, respectively. No other domains exhibited any significant decline (urinary, and bowel).</div></div><div><h3>Conclusions</h3><div>The evaluation of the primary results of the presented prospective phase II trial suggests that the proposed hypofractionated combined radiotherapeutic scheme is a well-tolerated, presenting no acute or early late severe adverse events. Moreover, patient reported outcomes confirm these results, since ","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527060","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":"GSOR10 Presentation Time: 5:45 PM","authors":"Darien N. Colson-Fearon M.P.H. , Akila Viswanathan M.D., M.P.H.","doi":"10.1016/j.brachy.2024.08.056","DOIUrl":"10.1016/j.brachy.2024.08.056","url":null,"abstract":"<div><h3>Purpose</h3><div>According to the American Brachytherapy Society, brachytherapy (BT) is recommended for the treatment of vaginal cancer, particularly cases of bulky and/or recurrent disease. However, previous studies noted a decline in rates during the early 2010s in accordance with similar declines observed in the use of BT for cervical cancer treatment. Recent studies have demonstrated potential recovery in BT utilization in cervical cancer. As such, this study examines more recent trends in BT utilization for vaginal cancer from 2004 to 2020 to assess whether a similar reversal in trends has begun since increased recognition of the importance of BT.</div></div><div><h3>Material and Methods</h3><div>This study analyzed data from the National Cancer Database (NCDB) of all patients with FIGO stage I to IVA vaginal cancer treated with pelvic radiation therapy between 2004 and 2020, identifying 6,412 patients. Patients were excluded if they were missing radiation treatment details, or if their survival was less than 5 months. A univariate log binomial regression with robust variance was used to estimate incidence rate ratios (IRRs) of BT utilization overtime and identify potential risk factors associated with receipt. Factors found to be significant in univariate analysis were considered for inclusion in a multivariate model to assess for a relationship with BT use. Additionally, a Cochran Armitage test was conducted to assess for overall trends in BT use.</div></div><div><h3>Results</h3><div>Brachytherapy use increased from 48.0% in 2004 to 67.7% in 2020. In univariate analysis, when compared to 2004, utilization began to significantly increase starting in 2018. Additionally, the test for linear trend was statistically significant (<em>p</em> <0.01). In multivariate model, factors associated with increased brachytherapy use included having non-Medicaid/Medicare government insurance (IRR: 1.28 95% CI: 1.04 - 1.58) when compared to being uninsured, receiving care at an academic/research program (IRR: 1.35 95% CI: 1.16 - 1.57), integrated cancer program (IRR: 1.22 95% CI: 1.04 - 1.42) or other specified type of program (IRR: 1.42 95% CI: 1.14 - 1.78) when compared to community cancer programs, having squamous histology (IRR: 1.08 95% CI: 1.02 - 1.15), and diagnosis after 2018 (IRR: 1.29 95% CI: 1.19 - 1.40). Factors associated with decreased use included American Indian or Alaskan Native race (IRR: 0.57 95% CI: 0.33 - 0.98) when compared to white race, age over 80 (IRR: 0.67 95% CI: 0.61 - 0.77) when compared to age less than 50, and stage II (IRR: 0.94 95% CI: 0.87 - 0.96), III (IRR: 0.69 95% CI: 0.65 - 0.74), or IVA (IRR: 0.41 95% CI: 0.35 - 0.48) disease when compared to stage I. Finally, geographic differences were also observed in BT use. Receiving treating in facilities located in New England (IRR: 0.84 95% CI: 0.74 - 0.95), Middle Atlantic (IRR: 0.87 95% CI: 0.79 - 0.95), South Atlantic (IRR: 0.85 95% CI: 0.78 - 0.93), East North C","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527070","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":"PP04 Presentation Time: 4:27 PM","authors":"Tonghe Wang PhD,&nbsp;Yining Feng PhD,&nbsp;Joel Beaudry MS,&nbsp;David Aramburu PhD,&nbsp;Marisa Kollmeier MD,&nbsp;Antonio L. Damato PhD","doi":"10.1016/j.brachy.2024.08.023","DOIUrl":"10.1016/j.brachy.2024.08.023","url":null,"abstract":"<div><h3>Purpose</h3><div>In the current procedure of high-dose-rate prostate brachytherapy, physicians insert catheters guided by ultrasound in the operating room. Subsequently, CT/MR/ultrasound images are acquired, and manual delineation of target/organs-at-risk is performed for treatment plan optimization. Catheter placement relies on physician experience, lacking feedback on plan quality during the implantation. Sub-optimal catheter implantation may lead to suboptimal plans or additional catheter adjustments requiring additional anesthesia time. In this study, we explored a novel automatic, real-time catheter tracking and target/organ segmentation method, which can be used with the current plan optimization program to potentially provide an instant plan quality feedback permitting physicians to optimize needle placement, and expediting the subsequent planning process.</div></div><div><h3>Materials and Methods</h3><div>A deep learning neural network was developed to take the last 5 frames of the real-time videos from ultrasound and provide the coordinates of all the catheters it detected, as well as the contours of prostate, rectum and urethra, on the last frame. After the ultrasound probe scanned the entire prostate region, the catheter coordinates on each frame were then fitted to corresponding 3D lines in order to produce the line functions of each catheter in 3D space, as well as the segmented contours of each frame were stacked together. A total of 518 patients who underwent prostate HDR brachytherapy as boost treatment in our clinic were retrospectively investigated, each of which had ultrasound images acquired, contoured and digitized for treatment planning after catheter placement. Among them, 482 patients were used for the training cohort and 36 patients were used for the testing cohort. The median number of catheters per patient was 14.</div></div><div><h3>Results</h3><div>Among the 477 catheters in the testing patients, the proposed method successfully detected 472 catheters, with an accuracy of 99.0%. The average displacement between the detected catheters and the ground truth catheters on 2D ultrasound images is 0.63±0.55 mm. The mean Dice score for prostate segmentation is 0.90±0.08. The maximum distance of rectum between ground truth and segmentation is 2.80±1.71 mm on average among all patients. The mean center distance of urethra between ground truth and segmentation is 0.76±0.56 mm. The mean time of processing each frame is 15.54±1.31 ms.</div></div><div><h3>Conclusion</h3><div>The accuracy and efficiency of the proposed method in tracking catheters and segmenting target and organs have been demonstrated with retrospective ultrasound data. It is seen that the proposed artificial intelligence-based method can facilitate a real-time, US-based automatic treatment planning program for prostate HDR brachytherapy.</div></div>","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527075","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":"PHSOR12 Presentation Time: 9:55 AM","authors":"Lindsey H. Bloom MS ,&nbsp;Julie Raffi PhD ,&nbsp;Rajesh Venkataramen PhD ,&nbsp;Yongbok Kim PhD ,&nbsp;Paul Segars PhD ,&nbsp;Diandra Ayala-Peacock MD ,&nbsp;Oana Craciunescu PhD","doi":"10.1016/j.brachy.2024.08.086","DOIUrl":"10.1016/j.brachy.2024.08.086","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Purpose&lt;/h3&gt;&lt;div&gt;Utilizing a female pelvic phantom and following TG-132 methodologies, we developed a novel digital phantom to validate the MR/TRUS contour-based elastic registration algorithm embedded in the commercial needle-tracking software developed by Eigen Health. The reliability of this registration algorithm is crucial for commissioning a pre-existing prostate needle-tracking biopsy system as a gynecological HDR brachytherapy tool.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Methods&lt;/h3&gt;&lt;div&gt;A previously optimized female pelvic phantom was embedded with six vitamin D fiducial markers. Four markers were placed on the exterior uterine surface (2 lateral, 1 anterior, 1 superior), and two were placed on the uterine interior (1 central, 1 anterior surface). A T2w MR image set of the phantom was acquired and segmented in 3DSlicer, an open-source image analysis software, to define the uterus and fiducials, which were then exported as STL files. Manual deformations were applied in Rhinoceros, a 3D CAD software, and proprietary scripts converted the deformed contours into raw binary images. A custom MATLAB code converted these images into DICOM format for import into Eigen's ProFuseCAD software which was used to segment the deformed uterus and define the fiducials as regions of interest (ROIs). The uterus contour and fiducial ROIs were then imported into Eigen's needle-tracking system. Using a BK Medical linear side-fire TRUS probe, a 150-degree lateral-to-lateral sweep of the non-deformed phantom was acquired. The uterus was segmented on the resulting 3D TRUS volume. Registration between the MRI and TRUS volumes was performed by first rigidly registering the two volumes in the sagittal and transverse planes based on 2 paired points on the uterus. A surface based elastic registration algorithm was then applied to complete the registration process. Target Registration Error (TRE) was estimated between the automatically marked centroid of each fiducial ROI and the manually marked fiducial centers from visual inspection in the acquired TRUS volume. This process was repeated for six different manual deformations applied to the digital phantom uterus to evaluate the system's registration quality. A control case without deformations was also examined.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;All six of the embedded fiducials were successfully visualized on MR and included in the digital phantom. The limited US FOV restricted visibility of the anterior fiducial, making its coordinates unreliable. For the five visible fiducials, the average ΔX, ΔY, ΔZ between the automatically generated point and the manually defined centroid point was 2.29±1.53, 0.94±1.02, 3.65±1.40mm, respectively. The overall average vector displacement of the location was 4.68 ± 1.49 mm.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Conclusion&lt;/h3&gt;&lt;div&gt;Our study demonstrates a novel method to validate the deformable registration algorithm used by the Eigen system. Distance results in each plane for all visible fiducials were wi","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526756","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":"PPP03 Presentation Time: 10:48 AM","authors":"Lucas C. Mendez MD, MSc ,&nbsp;Matt Mulligan BSc ,&nbsp;Douglas A. Hoover PhD ,&nbsp;Samih Mohamed MD ,&nbsp;Maria Thereza Starling MD ,&nbsp;Aneesh Dhar MD ,&nbsp;Rohann Correa MD, PhD ,&nbsp;Vikram Velker MD ,&nbsp;Joelle Helou MD ,&nbsp;Glenn Bauman MD ,&nbsp;Aaron Fenster PhD ,&nbsp;Gary Brahm MD ,&nbsp;David D'Souza MD ,&nbsp;Jason Vickress PhD","doi":"10.1016/j.brachy.2024.08.095","DOIUrl":"10.1016/j.brachy.2024.08.095","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Purpose&lt;/h3&gt;&lt;div&gt;Erectile disfunction (ED) is a common long-term side effect of any prostate cancer treatment. Radiation-related ED is thought to be a vascular process, related to venous occlusion caused by radiation. Low dose-rate (LDR) brachytherapy (BT) is a well-established treatment modality that has an undisputable dose conformality and a theoretical advantage in reducing dose to erectile-related structures when compared to EBRT options. Nevertheless, the role of vessel-sparing LDR-BT technique has not been previously described.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Materials and Methods&lt;/h3&gt;&lt;div&gt;PRIAPUS (NCT 04718987) is a prospective, single-arm clinical trial evaluating feasibility and dosimetry associated with a novel LDR BT technique that aims to spare ED-related structures, including the prostatic neurovascular bundles (NVB) contralateral to the index lesion and the penile bulb (Figure 1). The trial planned to accrue 15 patients with intermediate-risk prostate cancer staged with MRI, with clinically significant disease (CSD) contained to one lobe of the prostate. Primary objective was for 70% of patients to achieve acceptable dose to the target structure while sufficiently sparing ED-related structures. Dosimetry was evaluated on a one-month post-implant CT-scan. In order of priority, the trial's dosimetric goals are: target D90% ≥ 140 Gy, urethra D30% &lt; 130%, contralateral NVB median dose ≤ 50 Gy, and penile bulb D10% ≤ 50 Gy. The LDR BT workflow involved a pre-procedural prostate mpMRI for NVB definition, intra-operative use of a deformable image registration algorithm to translate NVB contours from pre-implant MRI to the live ultrasound images, and intraoperative planning using loose 125-Iodine radioactive seeds with a prescription dose of 145 Gy.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;Fifteen patients have been consented: one withdrew consent before receiving treatment, one awaits treatment, and 13 have been successfully treated with post-implant dosimetry available for analysis. In the one-month post-procedure scan, the mean target D90% was 153 Gy (SD ± 10 Gy). All patients but one had a target D90% &gt; 140 Gy. The mean urethra D30% was 129% (SD ±10%). The mean contralateral NVB D50% was 60 Gy (SD ± 13 Gy), with 10 of 13 implants failing to meet the pre-specified goal. For comparison, the ipsilateral NVB which was not spared received a mean D50% of 131 Gy (SD ± 33 Gy). The mean penile bulb D10% was 32 Gy (SD ± 13 Gy). Only two patients had a post-implant dosimetry that met all pre-specified criteria, and so this trial's primary dosimetric endpoint will not be met after the last patient receives treatment.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Conclusions&lt;/h3&gt;&lt;div&gt;The pre-specified dosimetric goals were found stringent and seldom achievable and future trials with this technique will require relaxation of the contralateral NVB constraint. While the primary dosimetric endpoint was not met, a substantial dose sparing to the contralateral NVB was achieved whi","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526978","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}