Brachytherapy最新文献

{"title":"PO78","authors":"Karel Arthur Hinnen, Iris Kuitems, Robbert Den Butter, Benjamin Arnods, Theo De Reijke, Zdenko Van Kesteren, Jette Bloemberg, Paul Breedveld, Bradley Pieters","doi":"10.1016/j.brachy.2023.06.179","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.179","url":null,"abstract":"","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135434522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Author Index of the Abstracts of the 2023 American Brachytherapy Society Annual Meeting","authors":"","doi":"10.1016/j.brachy.2023.09.003","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.09.003","url":null,"abstract":"","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135434597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PO84","authors":"Margaret Barker, Michael Campbell, Lisa Turner, A． Nisar M. Syed, Randy Wei, Peyman Kabolizadeh","doi":"10.1016/j.brachy.2023.06.185","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.185","url":null,"abstract":"Purpose Interstitial HDR brachytherapy involves precise, localized delivery to a high risk clinical target volume (HRCTV) with high dose gradients, sparing adjacent critical organs at risk (OAR). Due to the proximity of the rectum and bladder to the HRCTV, deviations in the applicator or catheter with respect to patient anatomy can change dose to those structures. Utilizing plastic interstitial catheters allows the patient to receive hyperthermia therapy during their course of interstitial treatment, however, the plastic catheters were observed to show significant deflection when the metal stylets are removed for treatment. The hyperthermia electrodes and the HDR source cable are both wires of approximately the same thickness. The purpose of this study is to assess the magnitude and deflection of the plastic catheters for gynecologic interstitial plans and determine whether using flexible wires for visualization on pre-treatment imaging is suitable for reconstructing the actual treatment received. Materials and Methods Eight patients with a total of 16 plans with re-treatment CT images where the metal stylets were utilized for plastic catheter (Best Medical) visualization were registered to a subsequent CT scan with the metal stylets removed. The originally planned (Brachyvision, Varian) 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, and target. Results Absolute 3D displacement for all patients was 3.5 mm ± 5.4 mm (n = 3217 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 0.75° ± 0.49° (n = 299 catheters for all treatment plans and patients, mean ± SD, p < 0.01). The plans were subsequently reconstructed on a pre-planning CT with flexible 20-gauge wires instead of metal stylets and are observed to correlate with the plans with no stylets with absolute 3D displacement and angular deflection of 1.1 ± 0.6 mm and 0.35 ± 0.3 respectively (n = 39 catheters, mean ± SD, p > 0.2). While the average target EQD2 D90 reduced by 5% ± 5%, four patients would have experienced a deviation from the prescription by >10%. There was an overall decrease in bladder D2cc and overall increase in rectal D2cc in the plans with the stylets removed. Conclusions Catheter reconstruction in interstitial gynecological treatments with CT imaging revealed significant changes in catheter positioning with respect to the target volume once the stylets are removed for treatment. Using flexible wires of similar thickness to the source cable allow for more accurate tracking during planning without distorting the final treatment plan. Interstitial HDR brachytherapy involves precise, localized delivery to a high risk clinical target volume (HRC","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135434601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PO37","authors":"Michael Salerno, Rachel Trevillian, Shibu Anamalayil, Megan Kassick, Seung Won Seol, Neil Taunk, Emily Hubley","doi":"10.1016/j.brachy.2023.06.138","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.138","url":null,"abstract":"Purpose Treating multiple fractions of cervical HDR BT with a single implant can reduce the overall package time of the procedure and reduces patient anesthesia and radiation oncology personnel resources due to reduced numbers of plans generated. Intracavitary (IC) and Intracavitary/Interstitial (IC/IS) applicators can shift between brachytherapy fractions, and bladder and bowel filling can cause interfraction variations of OAR dosimetry. Interfraction dosimetry variations of single implants have not been well-quantified and it is unclear whether an adaptive replan is required for each fraction. Methods and Materials 10 patients with locally advanced cervical cancer treated with HDR BT were included in this study: 5 consecutive IC (T&R applicator) and 5 consecutive hybrid IC/IS (T&R with interstitial needles). Each patient received 45Gy in 25 fractions of EBRT followed by 28Gy in 4 fractions of HDR MR-IGABT with Alatus Vaginal Balloon packing (Radiadyne, Latham, NY). BT was administered using a two-implant technique. After the first implant, fraction 1 was planned and delivered using CT and MRI. After overnight admission, a new CT was obtained prior to fraction 2 and rigidly registered to the fraction 1 CT using the applicator and cervix as landmarks. The bladder, rectum, and sigmoid colon were contoured and the treatment plan for fraction 1 was copied onto the fraction 2 CT. The same procedure was applied for fractions 3 and 4 with a new implant followed by a CT/MR-based plan generated for fraction 3, and an evaluation CT for fraction 4. The absolute interfraction change in EQD2 and cumulative EBRT+BT was calculated using an alpha/beta value of 3; all doses are reported in EQD2. Differences in interfraction variability between IC and IC/IS plans were investigated. Results The mean HRCTV volume was 17.8cc (8.1-27cc) for IC plans and 32.6cc (19.6-44.4cc) for IC/IS plans. All IC/IS plans had an average fraction of total dwell time of less than 20% in needles. The D2cc for bladder, rectum, and sigmoid were below the soft/hard EMBRACE II guidelines for all plans (80/90Gy, 65/75Gy, 65/75Gy, respectively). The mean single BT fraction D2cc to bladder, rectum, and sigmoid were 7.9Gy, 2.9Gy and 4.2Gy. The bladder D2cc displayed the greatest interfraction variability, with an average absolute interfraction difference of 1.8±1.3Gy, while rectum and sigmoid were 0.6±0.5Gy and 0.7±0.7Gy. Differences between IC and IC/IS plans were also compared. The mean single fraction D2cc to bladder was lower for IC/IS plans (7.2±1.0Gy) as compared to IC plans (8.7±0.4Gy). The mean single fraction D2cc to rectum and sigmoid were similar between the two methods (2.8±0.3Gy and 4.3±0.3Gy for IC/IS versus 2.9±0.3Gy and 4.1±0.3Gy for IC). The absolute interfraction D2cc difference was minimal with both applicators (Figure 1). The interfraction D2cc difference to bladder, rectum, and sigmoid was similar for IC/IS plans (1.8±1.1Gy, 0.6±0.5Gy and 0.7±0.8Gy) as compared to IC plans","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135434211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PO98","authors":"Gopishankar Natanasabapathi, Dayanand Sharma, Vellaiyan Subramani, Surendra Kumar Saini, Dhanabalan Rajasekaran","doi":"10.1016/j.brachy.2023.06.199","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.199","url":null,"abstract":"Purpose Development of brachytherapy template as a radiation treatment guidance device to localize deep seated tumors. Materials and Methods The template of specific size and dimension were designed using solid modeling computer-aided design (Solid Works, Dassault systemes). The design was further converted to 3D printing readable format (. stl format). All the parts of the design were printed in 3D printer (Phrozen Technology, Taiwan) using stereolithography technology (SLA). A resin material in liquid form was laid on the 3D printer platform for printing. Lifting speed of the printing plate was set at 40 mm/min. The retract speed was 150 mm/min. The exposure time was set at 3.5 s. The newly designed template with all accessories were scanned in an X-ray CT scanner for imaging compatibility purpose. Scanning parameters were as follows: Tube Voltage - 120 kV, slice thickness - 2.0 mm, Tube Current - 305 mA, pixel size - 0.6738 x 0.7638 mm2 and etc. Results The overall process took 3 hours to print the design with printing resolution of 50 microns. Various parts of the design were produced in a layer-by-layer fashion. By photochemical process, the chosen resin material cross-linked together to form polymers. In the imaging study the Hounsfield unit (HU) value of the resin material for template design was found to be 250 HU. The newly printed template had angled holes around 80 degrees to insert and maneuver interstitial needles. The template design was built in such a way that obturators, rectal probe and related accessories were easily positioned and immobilized in the template capable of tumor localization in real clinical situation. A rectal probe was built as well with the base template. Conclusions We are further developing a human pelvis phantom to test the efficacy of the new 3D printed template which we will show in our future studies. The ultimate goal of this study is to personalize patient treatment with an affordable and cost-effective solution. The newly designed template is capable of performing brachytherapy procedure. Further dosimetric validation study is required to explore the potential of the template for clinical use purpose. Development of brachytherapy template as a radiation treatment guidance device to localize deep seated tumors. The template of specific size and dimension were designed using solid modeling computer-aided design (Solid Works, Dassault systemes). The design was further converted to 3D printing readable format (. stl format). All the parts of the design were printed in 3D printer (Phrozen Technology, Taiwan) using stereolithography technology (SLA). A resin material in liquid form was laid on the 3D printer platform for printing. Lifting speed of the printing plate was set at 40 mm/min. The retract speed was 150 mm/min. The exposure time was set at 3.5 s. The newly designed template with all accessories were scanned in an X-ray CT scanner for imaging compatibility purpose. Scanning parameters were as follow","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135434372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PO10","authors":"Suneetha Mulinti, Mahaboob Basha Syed, Naga Satish Golla, Chandra Kumar Racharla, Sushil Beriwal","doi":"10.1016/j.brachy.2023.06.111","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.111","url":null,"abstract":"Purpose Clinicians at Aarhus University Hospital, Denmark developed the individualized 3D printed needle templates and Varian worked with Aarhus to develop this hybrid applicator with standard needle template. We started using this in our practice in 2022 and present our initial experience using this Aarhus ring and tandem MR compatible hybrid interstitial applicator with both straight and oblique needles in patients with locally advanced cervical carcinoma. Materials & Methods A total number of 22 patients from stage IB3 to IIIB were treated with MR based Image guided adaptive brachytherapy between March 2022 to January 2023, of which 17 patients were treated with Hybrid Interstitial brachytherapy with Aarhus applicator after completion of External Beam Radiotherapy. All patients were treated with External Beam radiation to a dose of 45 to 50 Gy in 25 fractions with SIB (55 Gy) to gross nodes along with concurrent weekly chemotherapy with Cisplatin @40 mg/m2. This was followed by brachytherapy to a total dose of 21 - 28 Gy in 3 to 4 fractions of IGABT with planning aims of HRCTV - D90 to receive > 85 to 90 Gy and keeping the EQD2 for 2cc Rectum, Sigmoid and Bladder to < 65 - 70 Gy, 70 - 75 Gy and 80 -85 Gy respectively. Each patient had 2 insertions of brachytherapy with 1 to 2 fractions with each insertion, done under short General anesthesia using real time trans abdominal USG guidance. Results A total number of 62 fractions have been performed with a median number of 4 (range 1-5 needles per patient. 8 patients required oblique needles. The average time from insertion to the first fraction treatment was 4 hours. Six hours gap was given between the two fractions done on same day. No acute Grade 3 complications have been recorded including bleeding or organ perforation. The Median EQD2 D90 of HRCTV was 91.77 Gy [80.1 to 101.9 Gy] and Median GTVp dose D98 was 110.12 Gy [81.1 to 123.5 Gy]. Median EQD2 for 2cc Bladder was 77.75 Gy [65.48 to 80.73Gy], Rectum was 56.36 [40.76 to 66.39Gy], Sigmoid colon - 61.18 Gy [52.24 to 72.88Gy], Small bowel - 58.4 [51.98 to 63.42Gy] 12 out of 17 patients completed first follow up at 3 months, out of which 11 patients showed complete response at cervix. Conclusion Our initial results show excellent dosimetry and no significant procedure related complications with MRI based IGABT in our clinic using hybrid applicator. Clinicians at Aarhus University Hospital, Denmark developed the individualized 3D printed needle templates and Varian worked with Aarhus to develop this hybrid applicator with standard needle template. We started using this in our practice in 2022 and present our initial experience using this Aarhus ring and tandem MR compatible hybrid interstitial applicator with both straight and oblique needles in patients with locally advanced cervical carcinoma. A total number of 22 patients from stage IB3 to IIIB were treated with MR based Image guided adaptive brachytherapy between March 2022 to January 2023, ","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135434374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PO36","authors":"Memory Fadziso Bvochora-Nsingo, Rohini Bhatia, Elliphine Gwangwava, Masud Rana Khan, Thabiso Itshabeng, Surbhi Grover","doi":"10.1016/j.brachy.2023.06.137","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.137","url":null,"abstract":"Purpose Cancer of the cervix is the most common malignancy treated at Gaborone Private Hospital, the only facility with radiotherapy in Botswana. Patients are treated with both curative and palliative intent. Curative patients are offered concurrent chemoradiotherapy followed by high dose rate brachytherapy. Palliative patients receive external beam radiation, commonly using AP-PA fields. Doses range from 8Gy Single fraction to 30Gy in ten fractions over two weeks. We report a patient receiving hemostatic high dose rate brachytherapy using intrauterine tandem insertion only. Materials and Methods In April 2022, a 43-year-old patient, HIV positive and virally suppressed, was referred to us with a four day history of severe vaginal bleeding. She had had a biopsy two months prior to presentation proving invasive squamous cell carcinoma of the cervix. She was staged as 4A with frozen pelvis and was on the waiting list for palliative radiation. However, the linear accelerator was down, and we were awaiting the engineer from neighboring South Africa. The patient had already been transfused a total of ten units of packed cells, three having been transfused the day prior to presentation. Her renal function was normal, and hemoglobin was 9g/dl. The patient presented in a stable condition with ECOG PS of two. After a quick history and physical examination, the patient gave signed consent for haemostatic brachytherapy. Vital signs were normal with blood pressure 100/60 mmHg, pulse 88 beats per minute and no fever. She was pre medicated with Cyclokapron 1 gram IV, Oxynorm 10 mg po, Paracetamol 1g IV and sedated with bromazepam 3mg po stat. A large bore cannula was inserted and a drip with IV Ringers lactate was inserted for slow infusion. Under sterile conditions, speculum showed a bulky cervical mass more than 8cm. Gentle probing with uterine sound identified the os. An 8cm tandem was inserted into the uterus (blind insertion no ultrasound guidance) and packing was done to stabilize the tandem. A CT scan was performed, and the images were transferred to the Nucleotron High Dose Rate Unit. A target volume was outlined on CT images. Since there was extensive rectal/ sigmoid and bladder invasion no OARs were contoured. (Fig 1). A plan was generated delivering 5.7 Gy to most of the GTV (EQD2 8Gy). The instruments were removed, and vaginal packing was done to stay overnight. Results The treatment was well tolerated and on completion of the treatment vaginal bleeding had stopped. Time from consultation to completion of treatment (i.e. haemostasis) was less than 90 minutes. Removal of vaginal pack the next morning showed no fresh bleeding. The patient reported vaginal spotting on day 3 when passing stool. Telephonic consultation after two weeks and one month confirmed no vaginal bleeding. The patient was referred back for consideration of colostomy so she could be assessed for further treatment. Conclusion In this patient we demonstrated that brachytherapy is an e","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135434387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PO75","authors":"Fred J. Schnell, Steven Schnell, Mark Quinn","doi":"10.1016/j.brachy.2023.06.176","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.176","url":null,"abstract":"Purpose The purpose of this study is to determine the efficacy of high dose-rate brachytherapy as a single modality treatment in patients with low and intermediate risk prostate cancer in a community setting. Materials and Methods Data was collected from 114 patients who were consecutively treated and received high dose-rate brachytherapy monotherapy for low and intermediate risk prostate cancer from 01/18/2017 to 12/14/2021. Patients had a median age at the start of treatment of 69, with a mean of 68.09 and range of 46 to 95 years. The clinical stage for all patients was T1c, with seventy-four (64.91%) patients having a Gleason score of 3+3=6, thirty-seven (32.46%) having a Gleason score of 3+4=7, and three (2.63%) having a Gleason score of 4+3=7. No patients exhibited perineural invasion and only five (4.39%) had 50% or more cores positive. The pretreatment PSA levels of all patients were between 2.2 and 17.5 ng/mL, with a median and mean of 5.8 and 6.7 ng/mL, respectively. Patients were administered either 3,800 cGy in two, three, or four fractions or 3,600 cGy in four fractions using HDR Iridium-192 as the radiation source. 104 patients (91.23%) received a dose of 3,800 cGy in four equal fractions, one patient (0.88%) in three equal fractions, and four patients (3.51%) in two equal fractions. Five patients (4.39%) received a dose of 3,600 cGy in four fractions. Patients receiving four fractions were given two fractions per day, two weeks apart, while patients receiving two fractions were given one fraction per day, two weeks apart. Following treatment, patients had scheduled follow-ups every three to six months after treatment to determine PSA levels. Results Post-treatment PSA levels were recorded for 108 patients, and this data was used to calculate a cure rate using the Phoenix definition of biochemical failure: a rise in PSA level 2.0 ng/mL above nadir. The definition used for a benign bounce is a rise in PSA level followed by a subsequent decrease in PSA level by greater than or equal to 0.5 ng/mL. PSA nadirs were recorded an average of 544.52 days after the end of treatment. There was a range of 85 to 1099 days and a median of 538.5 days. The average post-treatment PSA nadir was 0.83 ng/mL with a median of 0.50 ng/mL and range of less than 0.01 ng/mL to 4.51 ng/mL. Twenty-one (19.44%) of patients achieved a nadir value between 0.5 and 1.0 ng/mL, and fifty-one (47.22%) achieved a nadir value of below 0.5 ng/mL. Two patients experienced biochemical failure according to the Phoenix definition, as their PSA level rose 2.0 ng/mL above nadir with no subsequent decrease, resulting in a 98.15% success rate. Conclusions High dose-rate brachytherapy as a single modality treatment is successful in a community setting in treating low and intermediate risk prostate patients. The purpose of this study is to determine the efficacy of high dose-rate brachytherapy as a single modality treatment in patients with low and intermediate risk prostate cancer ","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135434416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PO79","authors":"Joel Beaudry, Gil'ad N. Cohen, Marisa Kollmeier, Daniel Gorovets, Michael Zelefsky, Antonio L. Damato","doi":"10.1016/j.brachy.2023.06.180","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.180","url":null,"abstract":"Purpose Promising results have been demonstrated using single fraction external beam for treatment of prostate cancer. Due to inherent differences of delivery between external beam and brachytherapy, the feasibility of replicating the external beam dosimetry in brachytherapy is investigated. Materials and Methods A retrospective study was performed using datasets of 120 HDR prostate patients from 6 different physicians in a single institution. The original plans were prescribed to 15Gy (with EBRT to follow). No changes were made to catheter placement, dwell positions, or contours. An in-house software, a linear optimizer with bounded and unbounded constraints, was used to elevate the dose to the entire gland to 24 Gy with no manual manipulation of the optimized plan/dwell times. The resulting plans were compared with published results of single fraction external beam plans to a dose of 24Gy, using the same dosimetric constraints [1]. Prostate D50%, Dmean, D95%, D2%, V24Gy, and V21.6Gy were reported, as well as OAR constraints D1cc for the rectum and urethra. Results Brachytherapy vs external beam prostate median metrics were 31.4 vs 24.5 Gy for Dmean; 22.1 vs 22.1 Gy for D95%; 79.8 vs 84.8% for V24Gy; 96.2 vs 96.2% for V21.6Gy. D1cc median metrics were 10.6 vs 18.5Gy for urethra and 18.2 vs 18.8Gy for rectum. Conclusion Dose escalation to the prostate was feasible and achieved similar results to external beam single fraction radiotherapy in terms of target coverage and OAR constraints. Due to the inherent differences of radiation delivery, the dose distributions differ primarily in hotspots and non-homogeneity that could lead to clinical differences. Delivery uncertainty is believed to be lower in brachytherapy, resulting in shrinking of margins and more accurate placement and delivery of hotspots, if desired. The retrospective study was based upon fixed prior implant geometries, therefore further work to investigate the placement of needles to further optimize dose conformality is ongoing. [1] Greco C et al. Safety and Efficacy of Virtual Prostatectomy With Single-Dose Radiotherapy in Patients With Intermediate-Risk Prostate Cancer: Results From the PROSINT Phase 2 Randomized Clinical Trial. JAMA Oncol. 2021 May 1;7(5):700-708. Promising results have been demonstrated using single fraction external beam for treatment of prostate cancer. Due to inherent differences of delivery between external beam and brachytherapy, the feasibility of replicating the external beam dosimetry in brachytherapy is investigated. A retrospective study was performed using datasets of 120 HDR prostate patients from 6 different physicians in a single institution. The original plans were prescribed to 15Gy (with EBRT to follow). No changes were made to catheter placement, dwell positions, or contours. An in-house software, a linear optimizer with bounded and unbounded constraints, was used to elevate the dose to the entire gland to 24 Gy with no manual manipulation of the","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135434423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PO107","authors":"Zhe Ji, Yang Ni, Chuang He, Xuequan Huang, Xin Ye, Junjie Wang","doi":"10.1016/j.brachy.2023.06.208","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.208","url":null,"abstract":"Purpose To compare the efficacy and safety of radioactive I-125 seed ablation brachytherapy (RSABT) and microwave ablation therapy (MWAT) in the treatment of inoperable early non-small cell lung cancer. Materials and Methods The data of patients with early non-small cell lung cancer who received CT guided RSABT and MWAT in our collaborative group from December 2010 to November 2020 were included. The main outcome measure was progression free survival, and the secondary outcome measures were overall survival rate and adverse events. Kaplan-Meier methods were used to analyze progression free survival and overall survival. Logistic and Cox regression were used for univariate and multivariate analysis, respectively. Results The median follow-up time of patients in RSABT and MWAT groups were 47.4 months and 60 months, respectively. Progression free survival (PFS) in the RSABT group was better than that in the MWAT group. The 1-year, 3-year and 5-year PFS of RSABT and MWAT group were 87.3%, 72.6%, 65.8% and 89.5%, 69.3% and 43.7% respectively (P = 0.011); the overall survival (OS) of RSABT group was slightly better than MWAT group. The 1-year, 3-year and 5-year OS of the two groups were 97.2%, 78.1%, 66.1% and 99%, 75.8% and 55% respectively (P = 0.112). Treatment technology was also an independent factor affecting PFS (HR 0.48, 95%CI 0.28-0.83, P=0.008) in multivariate Cox analysis. And gender and T stage were independent factors affecting PFS and OS (P < 0.05). There are no fatal operation related complications. Pneumothorax was the most common complication. The incidence of MWAT group was slightly higher than that of RSABT group, which were 50% and 39% respectively (P = 0.313). The incidence of pleural effusion in MWAT group was higher than that in RSABT group (44% and 14%, respectively, P < 0.001). The incidence of needle bleeding in RSABT group was higher than that in MWAT group (32% and 5%, respectively, P < 0.001). Conclusions The outcomes of RSABT in the treatment of early NSCLC is no less than MWAT, and the incidence of operation complications is also equivalent to MWAT, but further exploration is needed. To compare the efficacy and safety of radioactive I-125 seed ablation brachytherapy (RSABT) and microwave ablation therapy (MWAT) in the treatment of inoperable early non-small cell lung cancer. The data of patients with early non-small cell lung cancer who received CT guided RSABT and MWAT in our collaborative group from December 2010 to November 2020 were included. The main outcome measure was progression free survival, and the secondary outcome measures were overall survival rate and adverse events. Kaplan-Meier methods were used to analyze progression free survival and overall survival. Logistic and Cox regression were used for univariate and multivariate analysis, respectively. The median follow-up time of patients in RSABT and MWAT groups were 47.4 months and 60 months, respectively. Progression free survival (PFS) in the RSABT group wa","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135434434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}