Brachytherapy最新文献

{"title":"BP08 Presentation Time: 5:03 PM","authors":"Adam Chichel PhD, Adam Kluska PhD, Artur J. Chyrek PhD, Wojciech M. Burchardt PhD","doi":"10.1016/j.brachy.2024.08.032","DOIUrl":"10.1016/j.brachy.2024.08.032","url":null,"abstract":"<div><h3>Purpose</h3><div>A prospective mono-institutional non-randomized open-label study (NTC05142202) is being carried out to establish the role of adjuvant multicatheter interstitial high-dose-rate brachytherapy (HDR-BT) in doubly accelerated and radiobiologically equivalent irradiation scheme of 5 × 5,4 Gy delivered in 3 days of treatment (High Five, HiFi-APBI) compared to the adopted long-term standard of APBI realized in 4-5 days (7-8 × 4-4,3 Gy) in selected women with low-risk invasive breast cancer or carcinoma in-situ. It is to report an interim analysis on the first 1- and 3-month early toxicity profiles and 1- and 3-month early cosmetic outcome results of a novel fractionation scheme adjuvant to breast-conserving surgery.</div></div><div><h3>Material and Methods</h3><div>Early low-risk breast cancer patients (pT<sub>is-2</sub>N<sub>0</sub>) were recruited between October 2021 and December 2023 (recruitment closed on 12/31/2024 according to protocol). Postoperative adjuvant treatment with interstitial HDR-BT was given for three days (5 fractions of 5,4 Gy; 6 hours apart; total dose 27,0 Gy) on an outpatient basis. Follow-up (FU) is continued one-month post-treatment, then three months up to 2 years, and six months up to 5 years. Early toxicity incidence (radiodermatitis, hematoma, breast infection, intraoperative breast damage, breast pain) is being assessed according to Common Terminology Criteria for Adverse Events v5.0 (CTCAE) up to 3 months FU. We also assess early 1- and 3-month Harvard scale-based cosmetic outcomes and record patients' feedback on a four-grade subjective breast appearance scale (excellent, good, satisfying, poor). Photographic documentation is being secured.</div></div><div><h3>Results</h3><div>One hundred forty-seven women aged 65 (51-85) were enrolled. At the time of analysis, all patients reached 1-month FU, and 132 (89,9%) reached 3-month FU. Early toxicities at one-month FU were: radiodermatitis G1 - 4 (2.7%); hematoma G1 - 21 (14.3%); breast pain G1 - 24 (16.3%), G2 - 2 (1.4%). Early toxicities at three-month FU were: radiodermatitis G1 - 2 (1.5%); hematoma G1 - 4 (3%); breast pain G1 - 18 (13.6%), G2 - 1 (0.8%). No breast infections occurred. Patients subjectively assessed their cosmetic outcome after one-month post-treatment as excellent at 57.8%, good at 36.1%, satisfying at 5.4%, and poor at 0.7%; after three months, excellent at 61.4%, good at 31.1%, satisfying at 7.1%, and poor at 0.0%. Clinicians assessed cosmesis on the Harvard scale after one month as grade I - 9.5%, II - 81.6%, III - 8.9%, IV - none; after three months as grade I - 21.2%, II - 74.2%, III - 4.6%, IV - none.</div></div><div><h3>Conclusions</h3><div>The incidence of early 1- and 3-month toxicity events is low and improves quickly. Hematomas heal quickly and spontaneously. Rare local and slight painful sensations are more persistent but do not disturb patients' daily activity. Patients assess their cosmesis much better subjectively th","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":"142527276","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":"GPP04 Presentation Time: 10:57 AM","authors":"Robin Straathof MSc , Sharline M. van Vliet-Pérez MSc , Linda S. Wauben PhD , Ben J. Heijmen Prof. PhD , Inger-Karine K. Kolkman-Deurloo PhD , Remi A. Nout Prof. PhD , Jenny Dankelman Prof. PhD , Nick J. van de Berg PhD","doi":"10.1016/j.brachy.2024.08.090","DOIUrl":"10.1016/j.brachy.2024.08.090","url":null,"abstract":"<div><h3>Purpose</h3><div>The clinical introduction of novel medical devices (MDs) requires conformity to the Medical Device Regulation (MDR) 2017/745 in Europe, or the Food and Drug Administration (FDA) in the USA. Compliance is also required for hardware or software developed or modified in-house for investigational purposes, custom treatment, or hospital-specific procedures. This entails a significant workload for hospitals. For investigational MDs this includes documentation of, among others, device description, design controls, manufacturing procedures, risk analyses, and evaluations of device safety and effectiveness. This work describes our efforts from a regulatory perspective in the context of in-house development and evaluation of a novel 3D-printed brachytherapy (BT) applicator.</div></div><div><h3>Materials and Methods</h3><div>Figure 1 shows an overview of the implemented regulatory workflow. The patient-tailored ARCHITECT applicator contains optimised needle channels and is intended for locally advanced cervical cancer (LACC) patients. To establish a programme of design requirements, a process tree was constructed (IEC 62366-1:2015), and function and risk analyses (ISO 14971:2019) were performed with stakeholders. Several design iterations were created, 3D-printed, and evaluated by users in a phantom. A manufacturer was selected based on their QMS certification (ISO 13485:2016) and experience with selective laser sintering of PA-12. For this material, a biological evaluation plan (ISO 10993-1:2020) was created to demonstrate biocompatibility. Several pre-clinical evaluations were performed: (1) dose attenuation (TG-43:2004), (2) applicator channel temperature during steam sterilisation at 134°C and 3.04 bar, (3) virtual dose planning for 22 patients previously treated with a clinically used commercial applicator, and (4) needle deflection with varying insertion angles in a phantom.</div></div><div><h3>Results</h3><div>The final concept embodiment design of the ARCHITECT applicator consists of two 3D-printed halves connecting to a commercially available tandem. Evaluations showed that: (1) PA-12 had a water-equivalent response with dose attenuation differences <1% between dose depth curves for PA-12 and water, (2) in-channel temperatures of 134°C were maintained for the required 3 minutes, (3) virtual dose planning for all patients resulted in clinically acceptable plans that had similar or improved dose conformity in comparison with the clinically used configuration, and (4) maximum deviations from straight line needle paths amounted to 0.7-4.7 mm at 40 mm depth, depending on the insertion angle.</div></div><div><h3>Conclusions</h3><div>Regulatory aspects associated with the introduction of novel brachytherapy devices to the clinic have only been scarcely documented. In this work we provide a case example for the ARCHITECT applicator. A series of pre-clinical validations were performed to demonstrate safety and performance of the","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":"142527285","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":"GPP03 Presentation Time: 10:48 AM","authors":"Clara Fallone PhD ,&nbsp;Ali Golestani PhD ,&nbsp;Deepak Bhayana MD ,&nbsp;Daniel Cho PhD","doi":"10.1016/j.brachy.2024.08.089","DOIUrl":"10.1016/j.brachy.2024.08.089","url":null,"abstract":"<div><h3>Purpose</h3><div>The gold standard Brachytherapy (BT) treatment for cervical cancer uses MRI guidance. Some employ MRI-only BT planning, eliminating registration errors between MRI and CT. Challenges in MRI-only BT include accurately reconstructing applicators and catheters due to geometric distortion. Distortions should be &lt; 2 mm for MRI-only BT planning. The EMBRACE II protocol recommends acquiring T2-weighted sequences for contouring and T1-weighted or proton-density weighted sequences for applicator reconstruction. Various sequences have been assessed for MRI-only BT. The commercially-available General Electric (GE) PROPELLER (Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction) sequence has not yet been evaluated for this use. This T2-weighted sequence yields high contrast resolution and reduces motion artifact. This work evaluates the use of the PROPELLER sequence in MRI-only BT planning. The use of another commercially available sequence: 3D LAVA-FLEX (liver acceleration volume acquisition) is also assessed. Utilizing 3D LAVA FLEX enables acquiring a high resolution, high signal, T1-weighted image in a relatively short time.</div></div><div><h3>Materials and Methods</h3><div>A cylindrical water-equivalent gel phantom was created, incorporating a Venezia (Elekta) applicator with one straight and one oblique needle. Three plastic spheres were glued on the phantom as external coordinate markers. The phantom was scanned using the PROPELLER and 3D-LAVA Flex pulse sequences with a 1.5 Tesla GE wide-bore MRI scanner and body coil. Oblique axial slices oriented in the tandem plane were acquired. The phantom was also scanned on a Philips Big Bore RT CT scanner. The slice thickness was 4 mm for PROPELLER, 2 mm for 3D-LAVA FLEX, and 1.5 mm for CT. In-plane resolution was 1 mm for the MRI images and 0.6 mm for CT images. Images were imported into the Oncentra treatment planning system (Elekta, version 4.6.2). Library modelling was used to reconstruct the Venezia applicator; catheters were manually reconstructed. Physical dimensions measured included the distance between the tandem, needles, and external markers. Measurements acquired from the MRI images were compared to those acquired from CT; distortions were calculated as the absolute difference and a maximum was computed.</div></div><div><h3>Results</h3><div>Maximum distortions of five total geometric measurements in phantom were 1.3 mm for PROPELLER and 0.7 mm for 3D LAVA-FLEX. Figure 1 reveals axial and reconstructed sagittal images using the investigated sequences and CT for the phantom.</div></div><div><h3>Conclusion</h3><div>Given that distortions are within 2 mm and image quality and contrast is suitable for reconstruction and contouring, PROPELLER and 3D LAVA-FLEX are appropriate pulse sequences for MR-only BT planning, and their corresponding advantages can thus be exploited.</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":"142527286","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":"GPP02 Presentation Time: 10:39 AM","authors":"Linda Rossi PhD,&nbsp;Rik Bijman PhD,&nbsp;Henrike Westerveld MD, PhD,&nbsp;Miranda Christianen MD,&nbsp;Lorne Luthart RTT,&nbsp;Michele Huge RTT,&nbsp;Inger-Karine Kolkman-Deurloo PhD,&nbsp;Jan-Willem Mens MD,&nbsp;Huda Abusaris MD,&nbsp;Raymond de Boer MD,&nbsp;Sebastiaan Breedveld PhD,&nbsp;Ben Heijmen (Prof),&nbsp;Remi Nout MD (Prof)","doi":"10.1016/j.brachy.2024.08.088","DOIUrl":"10.1016/j.brachy.2024.08.088","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Purpose&lt;/h3&gt;&lt;div&gt;Fully automated adaptive treatment planning for image-guided cervical cancer brachytherapy following EMBRACE II planning aims, using ‘BiCycle’, was recently been developed. Favorable results were achieved in retrospective research studies [Oud et al., Radiother Oncol 148:143, 2020; Bijman et al., Radiother Oncol 170(S390), 2022; Rossi et al. Radiother Oncol 182(S92), 2023]. In this study, BiCycle was implemented parallel to the clinical routine to prospectively evaluate its impact on plan quality and workload. Dosimetrical parameters and planning times were prospectively collected as well as subjective plan scoring by five of the six clinicians performing cervical cancer brachytherapy.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Materials and Methods&lt;/h3&gt;&lt;div&gt;Between June 2022 and January 2023, max. 2 patients per week were included, if compatible with clinical workload. Each patient was treated with an intracavitary applicator with interstitial needles, using a manually generated plan, without modifying clinical practice. Manual plan generation was performed by an RTT in Oncentra-Brachy (OCB) (Elekta) followed by a manual plan adjustment togehter with the treating physician (if desired), leading to a Man_Adj plan used for delivery. After treatment, an automated plan was generated using BiCycle aiming at the same CTVHR D90% as in the Man_Adj plan (Auto plan generation). The plan was then imported into OCB and evaluated, and optionally adjusted without access to the Man_Adj plan by the same treating physician who also evaluated and adjusted the manual plan, resulting in an Auto_Adj plan. Next, the treating physician compared Auto_Adj and Man_Adj plans using Visual Analogue Scales (VAS) for i) overall plan quality, ii) target structures doses only, iii) OARs doses only and iv) loading pattern only. For each VAS, the clinician first selected the favorable plan and then expressed the importance of superiority using a 0-100 scale. Both for manual planning and autoplanning, times needed to generate and adjust the plan were recorded.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;Data of 41 fraction plans were included, resulting in 37 evaluable plans due to 3 not evaluated in time, and 1 missing informed consent. Auto_Adj plans resulted in superior plan quality compared to Man_Adj in almost all aspects. While CTVHR D90% and GTVRES D98% improved by 0.3 and 1.7 Gy, respectively, CTVIR D98% decreased by 1.3 Gy, while always remaining within constraints (results expressed in total EBRT+BT EQD2Gy doses). Auto_Adj reduced bladder, rectum, sigmoid and bowel D2cc by on average by 3.7, 3.0, 1.0, 1.4 Gy, respectively. Treating physicians expressed an overall preference for Auto_Adj, which was preferred in 28, 17, 30 and 7 plans out of 37 for VAS overall, CTV, OARs and loading pattern respectively, while Man_Adj was preferred in 2, 1, 2 and 9 plans respectively. Planning+adjustment times significantly reduced with automated planning for all fractions (Figure 1), with a r","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":"142527287","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":"PP05 Presentation Time: 4:36 PM","authors":"Mark Rivard Ph.D. ,&nbsp;Larry DeWerd Ph.D. ,&nbsp;Mauro Carrara Ph.D. ,&nbsp;Tomislav Bokulic Ph.D. ,&nbsp;Malcolm McEwen Ph.D. ,&nbsp;Thorsten Sander Ph.D. ,&nbsp;Thorsten Schneider Ph.D. ,&nbsp;Paula Toroi Ph.D.","doi":"10.1016/j.brachy.2024.08.024","DOIUrl":"10.1016/j.brachy.2024.08.024","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Purpose&lt;/h3&gt;&lt;div&gt;This presentation shares highlights of the International Atomic Energy Agency (IAEA) Technical Report Series 492 Code of Practice on brachytherapy (BT) dosimetry.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Methods&lt;/h3&gt;&lt;div&gt;This IAEA Code of Practice is addressed to both secondary standards dosimetry laboratories (SSDLs) and hospitals, not addressed to primary standards dosimetry laboratories (PSDLs), and is based on the use of well-type re-entrant ionization chambers. It applies to all BT sources with intensities measurable by such detectors. The dosimetry formalism, common procedures for reference dosimetry and for calibration, reference-class instrument assessment, and commissioning of well-type chamber system are described. This Code of Practice is aimed to enable common procedures to perform dosimetry of radioactive sources used in BT, excluding beta-emitting eye plaques/applicators as well as stranded seeds and mesh-type sources. Targeted radionuclide therapy and miniature electronic brachytherapy (eBT) devices were also excluded. It provides a description of the most accurate and sensitive calibration systems available at PSDLs and recommends suitable detectors and procedures for source strength measurements at SSDLs and hospitals.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;This Code of Practice consists of ten sections and six appendices. Following the introduction in Section 1 that frames the background and scope, Section 2 provides a description of the radioactive sources currently available for BT. The dosimetric quantities reference air kerma rate, air kerma strength and absorbed dose to water are discussed in Section 3, along with the dose-rate constant and other parameters important to dosimetrically characterize BT sources. Section 4 provides a detailed description of well-type ionization chamber instrumentation and defines the requisites for reference-class instruments. It also includes a description of HDR remote afterloaders. Section 5 contextualizes the dosimetry framework that defines dissemination of primary dosimetry standards down to the hospital level. Section 6 provides an overview of the available primary standards useful for BT calibrations. Their dissemination through the adoption of a well-type chamber dosimetry system is furthermore described. Section 7 defines the dosimetry formalism employed for the determination of the dosimetry quantities used herein. The general procedure to properly perform BT dosimetry with the well-type chamber is given in Section 8, along with a description of methods to check for short and long term stability of the measurement system. Section 9 deals with estimating uncertainties typically involved with source strength measurement of LDR and HDR sources. The way measured reference quantities are useful in the clinical practice for assessing the dose to the patient is outlined in Section 10. The main BT source categories and treatment delivery methods are briefly approached. Appendices are prov","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":"142526710","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":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":"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":"MSOR04 Presentation Time: 8:15 AM","authors":"Mélodie Cyr Ph.D. Biological and Biomedical Engineering ,&nbsp;Behnaz Behmand Ph.D. ,&nbsp;Naim Chabaytah M.Sc. ,&nbsp;Joud Babik B.Sc. ,&nbsp;Mirta Dumancic Ph.D. ,&nbsp;Joanna Li M.Sc. ,&nbsp;Guillaume St-Jean D.M.V, Ph.D., DACVP ,&nbsp;Shirin A. Enger Ph.D.","doi":"10.1016/j.brachy.2024.08.067","DOIUrl":"10.1016/j.brachy.2024.08.067","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Purpose&lt;/h3&gt;&lt;div&gt;Diffusing alpha-emitter radiation therapy (Alpha-DaRT) is a brachytherapy modality using implantable seeds impregnated with ∼2µCi of &lt;sup&gt;224&lt;/sup&gt;Ra to treat solid tumors. Short-lived alpha-particle emitting atoms are released in the decay chain of &lt;sup&gt;224&lt;/sup&gt;Ra. From this decay, &lt;sup&gt;220&lt;/sup&gt;Rn and &lt;sup&gt;212&lt;/sup&gt;Pb atoms are of interest due to their ability to diffuse among the tumor cells undergoing alpha decay and transforming into alpha-emitting daughters. The diffusion will contribute to a high-dose region up to a few mm around the source, overcoming the short-range of alpha-particles in tissue. The diffusion lengths (L&lt;sub&gt;diff&lt;/sub&gt;) of these alpha-emitting atoms vary across different tumor types, leading to a non-uniform dose distribution. This study investigates the L&lt;sub&gt;diff&lt;/sub&gt; in an orthotopic intra-rectal animal model designed for colorectal adenocarcinoma.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Materials and Methods&lt;/h3&gt;&lt;div&gt;HT-29 colorectal adenocarcinoma cells were injected into the submucosal layer of the intestinal wall of 28 NSG mice. The tumors growth and position were monitored using a 7T MRI scanner, until reaching 5-7 mm in diameter, then separated into control (n=9), inert (n=9) and active groups. The active group was further divided into two, whether Alpha-DaRT source was injected in rectal muscle (n=4) or in the tumor (n=6). The placement of the sources was confirmed by MRI. After four days of exposure, the tumors, and organs at risk (OARs) (ie. kidneys, bladder, and liver) were collected and measured using gamma spectroscopy, measuring the activity from &lt;sup&gt;212&lt;/sup&gt;Pb. Autoradiographs were acquired from the tumors and OARs histological slides using a Typhoon 9500. Slides were stained with H&amp;E, CD-31 and cleaved-caspase 3 (CC-3) for tissue damage, vascularity, and apoptosis, respectively. The autoradiography responses were fit with a diffusion model and the photostimulated luminescence (PSL) was converted into measured activities. A pathologist measured each groups’ necrotic areas, and the CD-31 and CC-3 tumor sections were scored for positively stained cells between each group.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;The initial findings indicate a measured L&lt;sub&gt;diff&lt;/sub&gt; of 0.23±0.09 mm in muscle tissue versus 0.5-1.0 mm in tumor, reflecting the inter-variability of the tumor microenvironment among mice and the placement of radiation sources (Figure 1A). A &lt;sup&gt;212&lt;/sup&gt;Pb diffusion leakage probability (&lt;sup&gt;212&lt;/sup&gt;Pb&lt;sub&gt;leakage&lt;/sub&gt;) was noted due to its ability to bind to proteins and/or red blood cells, leading to the escape of &lt;sup&gt;212&lt;/sup&gt;Pb from the tumor to the OARs. The &lt;sup&gt;212&lt;/sup&gt;Pb&lt;sub&gt;leakage&lt;/sub&gt; measured between 54-93 % for the tumors. A linear relationship between &lt;sup&gt;212&lt;/sup&gt;Pb&lt;sub&gt;leakage&lt;/sub&gt; and the activity uptake in the kidneys was observed. The kidneys had the highest activity of the OARs, measuring between 0.255±0.0025 kBq and 0.85±0.0046 kBq. The autoradiographs sh","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":"142526896","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":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":"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":"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":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":"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}

{"title":"GSOR07 Presentation Time: 5:30 PM","authors":"Alexandra Timea Kirsch Mangu (Medical Doctor)","doi":"10.1016/j.brachy.2024.08.053","DOIUrl":"10.1016/j.brachy.2024.08.053","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Purpose&lt;/h3&gt;&lt;div&gt;There are no international guidelines for optimal needle insertion method during interstitial intracavitary brachytherapy (IS-ICBT) for cervical cancer. We aimed to investigate the clinical feasibility and added value of Three-dimensional computed tomography angiography (3D-CTA) reconstruction of the origin of the uterine artery and its clinical significance guidance to optimize needle insertion in IS-ICBT using the interstitial cylinder applicator and Aarhus ring and Vienna Ring and to evaluate acute complications after needle insertion.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Materials and Methods&lt;/h3&gt;&lt;div&gt;We enrolled 85 patients with locally advanced cervical cancer (stage II to IIIC2) which were evaluated for in IS-BT at the Oncology Institute Ion Chiricuță Cluj-Napoca, Romania Department of Radiation Oncology. We performed for every patient a 3D-CTA before the needle implantation, in order to visualise uterine artery and its ascending/descending branches . Using 3D-CTA and reconstructed images of adaptive iterative dose resolution 3D (AIDR 3D) with display field of view (D-FOV), which are suitable for arteries with large and small diameters, and created the fusion images. Created images allowed the visual observation of vessel branch and by this technique we could determine optimal needle locations and insertion lengths based on the vessels position in order to avoid needle penetration of the artery or the proximity organs. The needle-channel axis was used as a reference to determine needle insertion. After the needle insertion based on the 3D-CTA another CT was performed for the contouring of the needles. Postinsertion adverse events were recorded during inpatient stay and at 6-week followup.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;Median followup time was at least 3 months. All patients were initially treated with external beam radiation therapy, median dose of 45 Gy. A total of 170 insertions were performed. No patient presented massive hemorrage because due to the 3D-CTA we were able to know exactly where the uterine artery or the branches are positioned and we avoided the penetration.When we performed the planning CT, there were no radiological evidence of needle intrusion(s) into the pelvic organs and no gastrointestinal complications were found. In this study, only 5 patients with grade 1 thrombocytopenia had minor vaginal bleeding after needle removal which was autolimited. The insertion of the needles was made under general anesteshia. Our results indicated that dizziness, nausea, and vomiting happened to be a constant side effect in this patients because of the general anestesia, but the side effects were acceptable. According to our findings, the most frequent acute adverse impact experienced by patients upon awakening from anaesthesia was pain. Patients experienced varying degrees of discomfort during the brachytherapy procedure. This could lead patients to reposition and alter the position of the applicator and needles, poten","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":"142527137","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}