Brachytherapy最新文献

{"title":"PO108","authors":"Ke Xu","doi":"10.1016/j.brachy.2023.06.209","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.209","url":null,"abstract":"","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"24 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":"135434425","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":"PO08","authors":"Jill Bennett, Cédric Bélanger, Philippe Chatigny, Luc Beaulieu, Alexandra Rink","doi":"10.1016/j.brachy.2023.06.109","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.109","url":null,"abstract":"Purpose Brachytherapy (BT) is an essential pillar in the treatment of cervical cancer. One method of gynecological (GYN) BT uses a transperineal catheter-guiding template in combination with an intrauterine (IU) tandem. Typically, catheter locations are decided using pre-BT imaging, and radiation treatment plans are then determined based on imaging taken after catheter insertion. Due to changes in patient anatomy once the IU tandem is inserted, this approach can lead to suboptimal tumor coverage, and often unused catheters, which contribute to increased implantation time, unnecessary tissue injury, and increased risk of bleeds. Images taken after insertion of the Template and APPlicator (post-TAPP) used in conjunction with a simple geometric catheter placement optimization algorithm may result in fewer unused catheters with better or equivalent dosimetry. In previous studies on prostate BT, the use of a Centroidal Voronoi Tessellation (CVT) algorithm for catheter optimization led to equivalent or superior treatment plans using fewer IS catheters compared to clinical cases. This work aims to verify these findings for cervical cancer BT. Materials and Methods Cases of locally advanced cervical cancer treated from 2016 to 2020 using IS BT with a Syed Neblett template were selected (N=12). Post-insertion imaging with target, organ-at-risk (OAR), and clinical catheter delineations were retrieved from the first BT fraction for each patient. CVT was used to simulate post-TAPP optimized catheters for each case by uniformly distributing catheters throughout a 2D projection of the target volume. The number of catheters in the CVT arrangement was equal to the number of catheters in the clinical implant, or the number of available template positions in the CVT planning region (defined as the high risk clinical target volume [HR-CTV] minus OARs projected onto the template plane), whichever number was lower. Treatment plans were then manually generated by a single expert for both the CVT and clinical catheter arrangements. Plan acceptability was evaluated via compliance with the EMBRACE-II dose-volume histogram limits in equieffective dose in 2 Gy per fraction (EQD2). Measures of dose inhomogeneity (%V150HR-CTV and %V200HR-CTV) were also recorded. Results The mean time for catheter optimization using CVT was 11.49 s. In all cases but 1, the CVT arrangements led to improved or EMBRACE-II compliant treatment plans with as many or fewer inserted catheters compared to the clinical cases (Figure 1). An increase in mean D90HR-CTV, D98HR-CTV, and D98IR-CTV was observed in the CVT group compared to the clinical group, as well as a statistically significant 2.2 Gy increase in mean D98GTVres (p < 0.05). A 2.2% increase in mean %V150HR-CTV was observed in the CVT group (p < 0.05). The mean number of unused catheters decreased from 4 in the clinical plans to 0 in the CVT plans (p < 0.001), and the acceptability rate increased from 50% with clinical catheters to 66.67% wit","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":"135434429","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":"PO54","authors":"Joel Poder, Philip Turner, Yaw Chin, Nadine Beydoun, Ese Enari, Andrew Howie","doi":"10.1016/j.brachy.2023.06.155","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.155","url":null,"abstract":"Purpose Low dose rate (LDR) brachytherapy has been proven to be an effective modality for monotherapy treatment of low-intermediate risk prostate cancer. The most commonly used treatment workflow follows a pre-planning approach utilising trans-rectal ultrasound (TRUS) images acquired under sedation, or nomogram planning based on manual measurements of prostate volume and dimensions. This study presents an alternative approach in which diagnostic magnetic resonance images (MRI) are used for the purpose of treatment planning, eliminating the necessity of an additional operating theatre procedure for the purposes of treatment planning, whilst tailoring the plan specifically to the patient's anatomy. Materials and Methods A retrospective study (n=10) was performed comparing the MRI and TRUS pre-planned approaches. The MRI pre-planned approach was retrospectively simulated by creating an LDR brachytherapy plan on diagnostic MR images using the Varian Variseed (v9.0.03) brachytherapy treatment planning system according to local protocols. This plan was then copied onto previously obtained TRUS planning images for the same patient. TRUS and MRI pre-plans were compared by evaluating plan quality metrics such as: the volume of the prostate receiving 100% (V100%), 150% (V150%), and 200% (V200%), dose to 90% of the prostate volume (D90%), as well as the rectum V100%, and urethra V125%. The prescription dose used in each plan was 145 Gy. The number of needles and number of seeds used in each approach was also compared. Statistical significance was tested for via the paired two sides t-test (p < 0.05). A prospective comparison study of operating theatre time usage is ongoing. Results Retrospective comparison of the planning approaches showed no statistically significant differences in plan quality metrics, apart from for the rectum V100%. The TRUS and MRI pre-planned approaches achieved an average rectum V100% of 0.14 cc and 0.33 cc (p = 0.008), respectively. Both approaches easily met the clinical constraint of rectum V100% < 1 cc, and thus the difference between the techniques was not clinically significant. All other plan quality metrics met departmentally defined clinical planning constraints for both the TRUS and MRI planned technique. Preliminary results comparing operating theatre time usage has shown significant time savings using the MRI-pre planning technique. Conclusions The MRI pre-planned approach for LDR prostate brachytherapy has been shown to achieve dosimetrically equivalent plans to TRUS based pre-plans, using less operating theatre resources. This technique is a safe and effective form of LDR prostate brachytherapy treatment planning for eligible patients. Low dose rate (LDR) brachytherapy has been proven to be an effective modality for monotherapy treatment of low-intermediate risk prostate cancer. The most commonly used treatment workflow follows a pre-planning approach utilising trans-rectal ultrasound (TRUS) images acquired under sedati","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"42 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":"135434512","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":"PO45","authors":"Shubhangi Shah, Xiaoyan Deng, Emma Fields, Dipankar Bandyopadhyay, Bridget Quinn","doi":"10.1016/j.brachy.2023.06.146","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.146","url":null,"abstract":"Purpose Endometrial cancer (EC) is the most common gynecologic malignancy and the fourth most common cancer in women [1]. Treatment is composed of a total hysterectomy, possibly followed by adjuvant chemotherapy or radiation therapy (RT) based on risk factors and staging [2]. Consistent follow up after treatment is integral to assessing for both toxicities and recurrence. Encouraging adjuvant vaginal dilator use has been shown to prevent vaginal stenosis, a common side effect of both surgery and RT [2]. However, about 9% of the female population in the USA face significant geographical barriers to receiving gynecologic cancer treatment [3]. Furthermore, previous studies showed being over 50 miles from a high-volume hospital was associated with increased risk of non-adherence care and increased mortality [4]. Increased time from endometrial biopsy to surgery is one documented factor that increased risk of poor outcomes [5]. This retrospective study evaluates if geographical location is associated with access to endometrial cancer care and post-radiation vaginal stenosis. Materials and Methods Patients enrolled in the study underwent surgery +/- RT for Stage I-IIIC endometrial cancer. Vaginal dilator use was recommended to all patients receiving RT. Vaginal length at follow up visits was measured with a vaginal sound. Data from patient charts was used to determine patient demographics, location, and follow up care. Results Forty-two patients had sufficient data for analysis. Average distance from the treatment hospital was 40.9 miles, 54% of patients lived in an urban county. Average number of days from an endometrial biopsy to surgical treatment was 43 days. Living >80 miles from the hospital was associated with an 80% increase in the days between an endometrial biopsy and surgery, compared to those living within 20 miles (p<0.01). Average months of follow up after surgery was 31. There was no impact of an increased distance from the hospital affecting months of follow-up care, vaginal stenosis, or dilator adherence. Conclusions This study provides evidence that living extreme distances from a high-volume cancer center is associated with delayed access to care. Furthermore, there's no direct impact of geography on post-RT vaginal dilation or adherence to care. Our findings suggest reduced discrimination in EC care despite geographical barriers. Further studies to evaluate impact of geography on mortality rates are needed. References: 1. BRAUN MM, OVERBEEK-WAGER EA, GRUMBO RJ. Diagnosis and Management of Endometrial Cancer. Am Fam Physician. 2016;93(6):468-474. Accessed January 30, 2023. https://www.aafp.org/pubs/afp/issues/2016/0315/p468.html2. Quinn, BA, et al. Change in Vaginal Length and Sexual Function in Women Who Undergo Surgery ± Radiation Therapy for Endometrial Cancer . Brachytherapy, 2023. In press.3. Shalowitz DI, Vinograd AM, Giuntoli RL. Geographic access to gynecologic cancer care in the United States. Gynecol Oncol. 2015;138(1):115-","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"9 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":"135434515","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":"PO09","authors":"Sergej Sergeich Romanenko","doi":"10.1016/j.brachy.2023.06.110","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.110","url":null,"abstract":"According to our experience, intracavitary brachytherapy of metastasis into vagina is not effective, especially in the case of volumetric tumor. As a rule we use intratissue brachytherapy with an intracavitary applicator of maximal diameter. Patient and Methods In 2020 Ca of transverse colon was diagnosed in a patient 58 years old, female. Ultrasonography, CT, MRI investigations and biopsy confirmed mts in both ovarian, pathological retroperitoneal, mesenteric and intracranial lymph nodes, left lobe of liver. First line of treatment included surgery, chemotherapy and hormone therapy. Operations: median laparotomy, right-sided hemicolectomy, atypical resection of the left lobe of liver. Chemotherapy (14 courses) - 8 courses with oxaliplatin and capecitabine and 6 courses with irinotecan. Mts into vagina were revealed a month after completing the treatment. 39,6 Gy (2.2 Gy*18 fractions) to pelvis with concomitant intracavitary brachytherapy 7Gy*4, total dose 28 Gy with normalization 5 mm from mucosa was delivered. In three months volumetric lesion in vagina right wall was confirmed at CT scans and visually. Intratissue brachytherapy with rigid needles was decided to use. Dose distribution and needle location is shown at the Figure. Needle insertion was done by freehand under anesthesia. Doses amounted to 30 Gy (1 time per week, 10 Gy fraction). Treatment was carried out at Microselectron 30 channels on the base of CT scans. Radiation reactions (burning and profuse discharge) lasted one month approximately. Results In 3 months CT with contrast did not show the presence of pathological foci in the body. And visually vagina had no signs of a tumor. Conclusion It was shown that intratissue brachytherapy is effective in the treatment of tumors affecting vagina. According to our experience, intracavitary brachytherapy of metastasis into vagina is not effective, especially in the case of volumetric tumor. As a rule we use intratissue brachytherapy with an intracavitary applicator of maximal diameter. In 2020 Ca of transverse colon was diagnosed in a patient 58 years old, female. Ultrasonography, CT, MRI investigations and biopsy confirmed mts in both ovarian, pathological retroperitoneal, mesenteric and intracranial lymph nodes, left lobe of liver. First line of treatment included surgery, chemotherapy and hormone therapy. Operations: median laparotomy, right-sided hemicolectomy, atypical resection of the left lobe of liver. Chemotherapy (14 courses) - 8 courses with oxaliplatin and capecitabine and 6 courses with irinotecan. Mts into vagina were revealed a month after completing the treatment. 39,6 Gy (2.2 Gy*18 fractions) to pelvis with concomitant intracavitary brachytherapy 7Gy*4, total dose 28 Gy with normalization 5 mm from mucosa was delivered. In three months volumetric lesion in vagina right wall was confirmed at CT scans and visually. Intratissue brachytherapy with rigid needles was decided to use. Dose distribution and needle location is shown ","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"184 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":"135434520","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":"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}