Pub Date : 2023-09-01DOI: 10.1016/j.brachy.2023.06.118
Juan Wang, Jinxin Zhao, Yansong Liang, Huiming Yu
Purpose To investigate the relationship between dose parameters and tumor volume reduction ratio after 125I seed implantation for recurrent cervical squamous cell carcinoma, and to obtain the better parameters to predict the curative effect. Methods 26 cervical squamous cell carcinoma patients with 30 lesions were studied retrospectively in our clinic. All patients underwent dose verification immediately after operation, and obtained postoperative D90(the minimum peripheral dose accepted by 90% target volume). The patients were followed up regularly. According to the CT images during the actual follow-up, the tumor volume reduction ratio at the end of t months (Rt),the tumor volume reduction ratio 1 month after operation (R1), the first month actual absorbed dose (D1m), the first month efficacy corrected absorbed dose (D1e), the first month sensitivity corrected absorbed dose (D1s) and the t months actual absorbed dose (Dt) were calculated. Curve fitting was performed for postoperative D90 and R1, and curve fitting was performed for postoperative D90, D1m, D1e, D1s and Rt to find the correlation between each parameter and tumor volume reduction ratio. Results The mean values of D90,D1m,D1e,D1s,Rt,R1were (105.4±22.8) Gy,(30.9±7.4)Gy,(37.1±8.9)Gy,(37.8±11.6)Gy,(39.4±17)%,(20.4±12)%. Postoperative D90 and R1, postoperative D90, D1m, D1e, D1s andRt all have positive relationship. The equations are as follows y=6.856×10-7x3-2.66×10-4x2+0.031x-0.879(R2=0.139),y=1.573×10-6x3-4.47×10-4x2+0.045x-0.967(R2=0.027),y=7.11×10-5x3-0.07x2+0.193x-1.402(R2=0.043),y=3.546×10-5x3-0.003x2+0.108x-0.744(R2=0.126),y=1.022×10-5x3-0.001x2+0.048x-0.275(R2=0.243). Conclusion PostoperativeD90, D1m, D1e and D1s were positively correlated with postoperative tumor volume reduction ratio, which can be used to predict the efficacy of primary recurrent cervical squamous cell carcinoma patients with particle implantation. Compared with D90 and D1m, and D1e , D1s can be better predictors . To investigate the relationship between dose parameters and tumor volume reduction ratio after 125I seed implantation for recurrent cervical squamous cell carcinoma, and to obtain the better parameters to predict the curative effect. 26 cervical squamous cell carcinoma patients with 30 lesions were studied retrospectively in our clinic. All patients underwent dose verification immediately after operation, and obtained postoperative D90(the minimum peripheral dose accepted by 90% target volume). The patients were followed up regularly. According to the CT images during the actual follow-up, the tumor volume reduction ratio at the end of t months (Rt),the tumor volume reduction ratio 1 month after operation (R1), the first month actual absorbed dose (D1m), the first month efficacy corrected absorbed dose (D1e), the first month sensitivity corrected absorbed dose (D1s) and the t months actual absorbed dose (Dt) were calculated. Curve fitting was performed for postoperative D90 and R1, and curve fitti
{"title":"PO17","authors":"Juan Wang, Jinxin Zhao, Yansong Liang, Huiming Yu","doi":"10.1016/j.brachy.2023.06.118","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.118","url":null,"abstract":"Purpose To investigate the relationship between dose parameters and tumor volume reduction ratio after 125I seed implantation for recurrent cervical squamous cell carcinoma, and to obtain the better parameters to predict the curative effect. Methods 26 cervical squamous cell carcinoma patients with 30 lesions were studied retrospectively in our clinic. All patients underwent dose verification immediately after operation, and obtained postoperative D90(the minimum peripheral dose accepted by 90% target volume). The patients were followed up regularly. According to the CT images during the actual follow-up, the tumor volume reduction ratio at the end of t months (Rt),the tumor volume reduction ratio 1 month after operation (R1), the first month actual absorbed dose (D1m), the first month efficacy corrected absorbed dose (D1e), the first month sensitivity corrected absorbed dose (D1s) and the t months actual absorbed dose (Dt) were calculated. Curve fitting was performed for postoperative D90 and R1, and curve fitting was performed for postoperative D90, D1m, D1e, D1s and Rt to find the correlation between each parameter and tumor volume reduction ratio. Results The mean values of D90,D1m,D1e,D1s,Rt,R1were (105.4±22.8) Gy,(30.9±7.4)Gy,(37.1±8.9)Gy,(37.8±11.6)Gy,(39.4±17)%,(20.4±12)%. Postoperative D90 and R1, postoperative D90, D1m, D1e, D1s andRt all have positive relationship. The equations are as follows y=6.856×10-7x3-2.66×10-4x2+0.031x-0.879(R2=0.139),y=1.573×10-6x3-4.47×10-4x2+0.045x-0.967(R2=0.027),y=7.11×10-5x3-0.07x2+0.193x-1.402(R2=0.043),y=3.546×10-5x3-0.003x2+0.108x-0.744(R2=0.126),y=1.022×10-5x3-0.001x2+0.048x-0.275(R2=0.243). Conclusion PostoperativeD90, D1m, D1e and D1s were positively correlated with postoperative tumor volume reduction ratio, which can be used to predict the efficacy of primary recurrent cervical squamous cell carcinoma patients with particle implantation. Compared with D90 and D1m, and D1e , D1s can be better predictors . To investigate the relationship between dose parameters and tumor volume reduction ratio after 125I seed implantation for recurrent cervical squamous cell carcinoma, and to obtain the better parameters to predict the curative effect. 26 cervical squamous cell carcinoma patients with 30 lesions were studied retrospectively in our clinic. All patients underwent dose verification immediately after operation, and obtained postoperative D90(the minimum peripheral dose accepted by 90% target volume). The patients were followed up regularly. According to the CT images during the actual follow-up, the tumor volume reduction ratio at the end of t months (Rt),the tumor volume reduction ratio 1 month after operation (R1), the first month actual absorbed dose (D1m), the first month efficacy corrected absorbed dose (D1e), the first month sensitivity corrected absorbed dose (D1s) and the t months actual absorbed dose (Dt) were calculated. Curve fitting was performed for postoperative D90 and R1, and curve fitti","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"69 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":"135434410","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}
Pub Date : 2023-09-01DOI: 10.1016/j.brachy.2023.06.158
Philippe Chatigny, Cédric Bélanger, Éric Poulin, Luc Beaulieu
Purpose In the past years, a key improvement in the generation of treatment plans in high-dose-rate (HDR) brachytherapy comes from the development of multicriteria optimization (MCO) algorithms that generate thousands of pareto optimal plans within seconds. This brings a shift, from the objective of generating an acceptable plan to choosing the best plans out of thousands. Not only does the chosen plan depend on the planner, it also takes about 5-10 minutes to choose the preferred plan. The purpose of the present work is to speed up this process and to find a common ground for different specialists regarding the plan quality. Materials and Methods An AI algorithm based on the ResNet deep neural network architecture is developed to choose the best plan(s) from the generated plans. The algorithm classifies the plans, from the 3D dose distribution and anatomical structures, in 3 different classes, (1) violating hard (minimum) criteria, (2) respecting hard criteria and (3) respecting soft criteria, with every class being more stringent than the last one (increase in plan quality). The three classes are based on dosimetric criteria used at our institution for 15 Gy in a single fraction. For the classification, the more confident the model is that a plan belongs to class 3, the better is the plan. To mimic the behaviour of experts, visual-like criteria are implemented for the bladder, rectum and urethra. Visual criteria are defined as 100% and 125% isodose distance from the organ at risk. During training, the algorithm learns the link between the inputs (3D dose and anatomy) and outputs (visual-like and DVH's criteria). 850 previously treated prostate's cancer patients are used for the training and another set of 20 patients previously evaluated by two experts (clinical medical physicist) as part of an inter-observer MCO study are used for validation. For the training, 100 plans are generated for each patient using MCO and 27 000 plans are chosen at random to have the same quantity in each class. A NVIDIA GeForce RTX 3090 is used for training. Results The model takes 20 s to classify 2000 plans in order of preference (vs 5-10 mins for experts to rank 4 preferred plans). Currently, the training time is not optimized and it takes less than 2 days to train on the 27 000 plans with 75 epochs. For the 20 validation patients, 39.9 ± 20.2%, 46.4 ± 15.3% and 14.5 ± 21.9% of the plan are in class 1, 2 and 3 respectively. Table 1 shows the results obtained on 20 cases, each with 2000 plans; the mean and deviation are calculated based on the plan chosen by the model and by the experts. The table includes the best ranked and worst ranked plan of class 3. Looking at the best plan according to the model and comparing it with the plan chosen by the two experts show that the behaviour is similar. Out of the 40 chosen plans by the two experts, on 3 occasions our model ranked the same plan as the best plan. Looking more in depth, we find that the median ranking of the p
{"title":"PO57","authors":"Philippe Chatigny, Cédric Bélanger, Éric Poulin, Luc Beaulieu","doi":"10.1016/j.brachy.2023.06.158","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.158","url":null,"abstract":"Purpose In the past years, a key improvement in the generation of treatment plans in high-dose-rate (HDR) brachytherapy comes from the development of multicriteria optimization (MCO) algorithms that generate thousands of pareto optimal plans within seconds. This brings a shift, from the objective of generating an acceptable plan to choosing the best plans out of thousands. Not only does the chosen plan depend on the planner, it also takes about 5-10 minutes to choose the preferred plan. The purpose of the present work is to speed up this process and to find a common ground for different specialists regarding the plan quality. Materials and Methods An AI algorithm based on the ResNet deep neural network architecture is developed to choose the best plan(s) from the generated plans. The algorithm classifies the plans, from the 3D dose distribution and anatomical structures, in 3 different classes, (1) violating hard (minimum) criteria, (2) respecting hard criteria and (3) respecting soft criteria, with every class being more stringent than the last one (increase in plan quality). The three classes are based on dosimetric criteria used at our institution for 15 Gy in a single fraction. For the classification, the more confident the model is that a plan belongs to class 3, the better is the plan. To mimic the behaviour of experts, visual-like criteria are implemented for the bladder, rectum and urethra. Visual criteria are defined as 100% and 125% isodose distance from the organ at risk. During training, the algorithm learns the link between the inputs (3D dose and anatomy) and outputs (visual-like and DVH's criteria). 850 previously treated prostate's cancer patients are used for the training and another set of 20 patients previously evaluated by two experts (clinical medical physicist) as part of an inter-observer MCO study are used for validation. For the training, 100 plans are generated for each patient using MCO and 27 000 plans are chosen at random to have the same quantity in each class. A NVIDIA GeForce RTX 3090 is used for training. Results The model takes 20 s to classify 2000 plans in order of preference (vs 5-10 mins for experts to rank 4 preferred plans). Currently, the training time is not optimized and it takes less than 2 days to train on the 27 000 plans with 75 epochs. For the 20 validation patients, 39.9 ± 20.2%, 46.4 ± 15.3% and 14.5 ± 21.9% of the plan are in class 1, 2 and 3 respectively. Table 1 shows the results obtained on 20 cases, each with 2000 plans; the mean and deviation are calculated based on the plan chosen by the model and by the experts. The table includes the best ranked and worst ranked plan of class 3. Looking at the best plan according to the model and comparing it with the plan chosen by the two experts show that the behaviour is similar. Out of the 40 chosen plans by the two experts, on 3 occasions our model ranked the same plan as the best plan. Looking more in depth, we find that the median ranking of the p","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":"135434422","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}
Pub Date : 2023-09-01DOI: 10.1016/j.brachy.2023.06.216
Miren Gaztañaga, Virginia Álvarez, Javier De Areba, Saadia Tremolada, Pino Alcántara, Elena Cerezo, Juan Antonio Corona, Anxela Doval, Fernando Puebla, Noelia Sanmamed, Manuel Gonzalo Vázquez
Purpose Perioperative accelerated partial breast irradiation with multicatheter interstitial brachytherapy is an alternative to the postoperative option that offers advantages in terms of specificity and comfort for patients as it avoids a second procedure. Since the simulation CT scan is performed 48 hours after the intervention, immediate tissue changes as air gaps can occasionally be observed. To our knowledge, there is no literature published on this regard, so the aim of this study was to assess the impact of significant air gaps when planning and treating multicatheter perioperative breast cancer brachytherapy. Methods and Materials Two consecutive cases with air gaps > 6 cc were included. For each case, a planning CT scan was performed 48 hours after the surgical procedure (tumorectomy + catheter insertion). Treatment planning was performed according to the department protocol and administered in an ultra-fractionated scheme: 3 fractions of 745 cGy every 12 hours. A second CT scan was performed right after the last treatment fraction, before the catheter removal. The air gaps have been contoured in both pre and post-treatment CTs and their volumes have been compared. The scans have been fused and the dosimetric differences have been evaluated. A total of 13 catheters have been analyzed in both scans. Results A volume reduction (-10% and -30% for each case) has been observed in the post-treatment air gap. Of the 13 catheters compared in the CT scans fusion, the catheter position displacement inside CTV was ≤ 1.5 mm in 12 of them (median displacement 1 mm), with one catheter displaced 2.7 mm in the post-treatment CT. Mean CTVD90 and V100 variation in the pre and post-treatment scans were -1.5 and -1.7% respectively. Dose variations in surrounding organs were: Skin Dmax -10 and -3%, Ribs Dmax +15 and +15% and Ipsilateral Lung Dmax +12 and +13%. Dosimetric disparities did not exceed tolerance and coverage limits in any case. Conclusions With two cases analyzed, the volumetric reduction of the air gaps does not seem to affect the geometry of the implants, with most of the catheters remaining stable in their initial position. Discrete changes in the coverage parameters and doses to OARs fulfill the pre-established constraints. The confirmation of these results as well as the clinical relevance of these changes has to be examined in future studies including more patients. Perioperative accelerated partial breast irradiation with multicatheter interstitial brachytherapy is an alternative to the postoperative option that offers advantages in terms of specificity and comfort for patients as it avoids a second procedure. Since the simulation CT scan is performed 48 hours after the intervention, immediate tissue changes as air gaps can occasionally be observed. To our knowledge, there is no literature published on this regard, so the aim of this study was to assess the impact of significant air gaps when planning and treating multicatheter perioperati
{"title":"PO115","authors":"Miren Gaztañaga, Virginia Álvarez, Javier De Areba, Saadia Tremolada, Pino Alcántara, Elena Cerezo, Juan Antonio Corona, Anxela Doval, Fernando Puebla, Noelia Sanmamed, Manuel Gonzalo Vázquez","doi":"10.1016/j.brachy.2023.06.216","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.216","url":null,"abstract":"Purpose Perioperative accelerated partial breast irradiation with multicatheter interstitial brachytherapy is an alternative to the postoperative option that offers advantages in terms of specificity and comfort for patients as it avoids a second procedure. Since the simulation CT scan is performed 48 hours after the intervention, immediate tissue changes as air gaps can occasionally be observed. To our knowledge, there is no literature published on this regard, so the aim of this study was to assess the impact of significant air gaps when planning and treating multicatheter perioperative breast cancer brachytherapy. Methods and Materials Two consecutive cases with air gaps > 6 cc were included. For each case, a planning CT scan was performed 48 hours after the surgical procedure (tumorectomy + catheter insertion). Treatment planning was performed according to the department protocol and administered in an ultra-fractionated scheme: 3 fractions of 745 cGy every 12 hours. A second CT scan was performed right after the last treatment fraction, before the catheter removal. The air gaps have been contoured in both pre and post-treatment CTs and their volumes have been compared. The scans have been fused and the dosimetric differences have been evaluated. A total of 13 catheters have been analyzed in both scans. Results A volume reduction (-10% and -30% for each case) has been observed in the post-treatment air gap. Of the 13 catheters compared in the CT scans fusion, the catheter position displacement inside CTV was ≤ 1.5 mm in 12 of them (median displacement 1 mm), with one catheter displaced 2.7 mm in the post-treatment CT. Mean CTVD90 and V100 variation in the pre and post-treatment scans were -1.5 and -1.7% respectively. Dose variations in surrounding organs were: Skin Dmax -10 and -3%, Ribs Dmax +15 and +15% and Ipsilateral Lung Dmax +12 and +13%. Dosimetric disparities did not exceed tolerance and coverage limits in any case. Conclusions With two cases analyzed, the volumetric reduction of the air gaps does not seem to affect the geometry of the implants, with most of the catheters remaining stable in their initial position. Discrete changes in the coverage parameters and doses to OARs fulfill the pre-established constraints. The confirmation of these results as well as the clinical relevance of these changes has to be examined in future studies including more patients. Perioperative accelerated partial breast irradiation with multicatheter interstitial brachytherapy is an alternative to the postoperative option that offers advantages in terms of specificity and comfort for patients as it avoids a second procedure. Since the simulation CT scan is performed 48 hours after the intervention, immediate tissue changes as air gaps can occasionally be observed. To our knowledge, there is no literature published on this regard, so the aim of this study was to assess the impact of significant air gaps when planning and treating multicatheter perioperati","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"106 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":"135434426","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}
Pub Date : 2023-09-01DOI: 10.1016/j.brachy.2023.06.151
Michael Jason Gutman, Tianming Wu, Christina Son, Hania Al-Hallaq, Yasmin Hasan
Purpose Triple tandem brachytherapy (TTB) provides superior coverage of the uterus and minimizes dose to OARs compared to single or dual tandem therapy, per prior dosimetric analysis of 3 representative cases (1). We report the technical feasibility and dosimetry of TTB in a cohort of patients with medically inoperable endometrial cancer (EC). Materials and Methods An IRB approved retrospective review was performed of all medically inoperable EC patients treated definitively with TTB ± external beam radiotherapy (EBRT) between 2014-2021 at a single institution (n=30). Patients underwent off-line MRI which was fused for planning (n=24, 80%) and all underwent intraoperative transabdominal ultrasound for dilation and device placement. Patients had FIGO stage 1a-4b disease; patients with ≥ stage 2 disease received TTB +/- ovoids. Kaplan-Meier estimates were generated to estimate local failure-free survival (LFFS). The equivalent dose in 2-Gy fractions (EQD2) constraints for dose to 2cc (D2cc) of the bladder, rectum, and bowel were <90Gy, <75Gy, and <65Gy, respectively, per ABS guidelines. The cumulative D90% (minimum dose to 90% of volume) in EQD2 was calculated for GTV and CTV and the organs at risk (OAR) for each patient. Statistics reported are median values and ranges. The dwell time contribution from each tandem was collected. Results Of 30 patients, 93.3% received EBRT and TTB. Mean age at time of diagnosis was 65.3 years (range: 40.5-88.7 years). The median BMI was 48.1 (range: 27.8-69). The median prescribed doses were 45 Gy (range: 21-50.4 Gy) for EBRT and 22.25 Gy in 5 fractions (range: 16.5-49.1 Gy) for brachytherapy. The median cumulative EQD2 to the GTV was 78.6 Gy (range: 67.8- 86.6) and to the CTV was 67.6 Gy (range: 48- 79.8), of which the TTB contributed a median EQD2 of 33.8 Gy and 23.3 Gy to the GTV and CTV, respectively. The central tandem was not placed for 4 patients (13.3%) due to concern for posterior cervix and/or posterior uterine wall perforation. In the entire cohort, the central tandem contributed at least 10% and 15% of the dwell time in 77% (n=23) and 60% (n=18) of patients, respectively (Figure 1). In one third of patients, the central tandem contributed ≥30% of the dwell time. The lateral tandems contributed the majority (82%, range: 32-100%) of total dwells. Median follow up was 32.1 months (1.7-93.6 months). Kaplan-Meier-estimated 1-/5-yr LFFS was 96.2%/84.1%. The cumulative D2cc: 71.0Gy (range: 25.2-91.2Gy) to the bladder, 53.6Gy (range: 25.2-76.2Gy) to the rectum, and 58.1Gy (range: 14.1-72Gy) to the small bowel. No procedure-related perforation, bleeding or acute complication occurred intra- or post-operatively. Conclusions TTB + EBRT for inoperable EC patients was safe and acceptable target coverage was achieved in most cases. While posterior/central tandem insertion may not be feasible for all patients in our experience, this limitation was not prohibitive to adequate dose distribution and local control. Furthe
{"title":"PO50","authors":"Michael Jason Gutman, Tianming Wu, Christina Son, Hania Al-Hallaq, Yasmin Hasan","doi":"10.1016/j.brachy.2023.06.151","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.151","url":null,"abstract":"Purpose Triple tandem brachytherapy (TTB) provides superior coverage of the uterus and minimizes dose to OARs compared to single or dual tandem therapy, per prior dosimetric analysis of 3 representative cases (1). We report the technical feasibility and dosimetry of TTB in a cohort of patients with medically inoperable endometrial cancer (EC). Materials and Methods An IRB approved retrospective review was performed of all medically inoperable EC patients treated definitively with TTB ± external beam radiotherapy (EBRT) between 2014-2021 at a single institution (n=30). Patients underwent off-line MRI which was fused for planning (n=24, 80%) and all underwent intraoperative transabdominal ultrasound for dilation and device placement. Patients had FIGO stage 1a-4b disease; patients with ≥ stage 2 disease received TTB +/- ovoids. Kaplan-Meier estimates were generated to estimate local failure-free survival (LFFS). The equivalent dose in 2-Gy fractions (EQD2) constraints for dose to 2cc (D2cc) of the bladder, rectum, and bowel were <90Gy, <75Gy, and <65Gy, respectively, per ABS guidelines. The cumulative D90% (minimum dose to 90% of volume) in EQD2 was calculated for GTV and CTV and the organs at risk (OAR) for each patient. Statistics reported are median values and ranges. The dwell time contribution from each tandem was collected. Results Of 30 patients, 93.3% received EBRT and TTB. Mean age at time of diagnosis was 65.3 years (range: 40.5-88.7 years). The median BMI was 48.1 (range: 27.8-69). The median prescribed doses were 45 Gy (range: 21-50.4 Gy) for EBRT and 22.25 Gy in 5 fractions (range: 16.5-49.1 Gy) for brachytherapy. The median cumulative EQD2 to the GTV was 78.6 Gy (range: 67.8- 86.6) and to the CTV was 67.6 Gy (range: 48- 79.8), of which the TTB contributed a median EQD2 of 33.8 Gy and 23.3 Gy to the GTV and CTV, respectively. The central tandem was not placed for 4 patients (13.3%) due to concern for posterior cervix and/or posterior uterine wall perforation. In the entire cohort, the central tandem contributed at least 10% and 15% of the dwell time in 77% (n=23) and 60% (n=18) of patients, respectively (Figure 1). In one third of patients, the central tandem contributed ≥30% of the dwell time. The lateral tandems contributed the majority (82%, range: 32-100%) of total dwells. Median follow up was 32.1 months (1.7-93.6 months). Kaplan-Meier-estimated 1-/5-yr LFFS was 96.2%/84.1%. The cumulative D2cc: 71.0Gy (range: 25.2-91.2Gy) to the bladder, 53.6Gy (range: 25.2-76.2Gy) to the rectum, and 58.1Gy (range: 14.1-72Gy) to the small bowel. No procedure-related perforation, bleeding or acute complication occurred intra- or post-operatively. Conclusions TTB + EBRT for inoperable EC patients was safe and acceptable target coverage was achieved in most cases. While posterior/central tandem insertion may not be feasible for all patients in our experience, this limitation was not prohibitive to adequate dose distribution and local control. Furthe","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":"135434430","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}
Pub Date : 2023-09-01DOI: 10.1016/j.brachy.2023.06.172
Hong Zhang, Catherine Liu
Purpose High-Dose-Rate Brachytherapy (HDR-BT) is an effective yet under-utilized treatment option for localized prostate cancer. Many studies have shown excellent long-term biochemical-failure-free survival outcomes with limited toxicity from HDR-BT as monotherapy for low- or intermediate-risk prostate cancer. However, due to higher start-up costs, less reimbursement, and inadequacy in residency training, far fewer radiation facilities are offering BT than external beam radiation (EBRT). Here, we performed a single-center, retrospective cohort study to evaluate the travel burdens put on patients who received BT as monotherapy at our high-volume center and if they had chosen external beam radiation close to home for localized prostate cancer. Materials and Methods From 1/1/2019 to 12/31/2022, 69 men were treated with HDR-BT as monotherapy at our brachytherapy center, receiving 27 Gy in 2 fractions, one week apart. Sixty-eight men had low- or intermediate-risk prostate cancer (Table). The travel burden for HDR-BT as monotherapy was estimated by collecting the distance between each patient's home address to our BT center (BT-D). The distance between each patient's home address and the nearest EBRT facility (EBRT-D) was also collected. The total travel burden for EBRT was then calculated, assuming a standard regiment of 28 fractions was used. Results Of the 69 patients who received BT for prostate cancer, the average age was 67.9 years, the overwhelming majority were white (96%), and all had insurance. The median and average EBRT-D were 5.5 and 8.3 miles, respectively. The median and average BT-D were 21 and 37.4 miles, respectively. However, due to the fewer visits required for BT (2 versus 28 trips), the total BT travel burden (median 84 miles, average 150.0 miles) was significantly less than for these patients if they had chosen EBRT instead (median 308 miles, average 462.5 miles) (p<0.01). On average, by choosing BT instead of EBRT, these patients reduced their travel burden by 312.5 miles. Conclusions We observed a significantly decreased overall travel burden for HDR-BT as monotherapy compared with EBRT in our cohort of patients with localized prostate cancer, despite a longer travel distance to our BT center than a nearby EBRT facility. Our study supports that HDR-BT as monotherapy remains a practical and preferred option for patients with localized prostate cancer, not only for its proven safety and efficacy but also decreased overall travel burden compared with definitive EBRT therapy. High-Dose-Rate Brachytherapy (HDR-BT) is an effective yet under-utilized treatment option for localized prostate cancer. Many studies have shown excellent long-term biochemical-failure-free survival outcomes with limited toxicity from HDR-BT as monotherapy for low- or intermediate-risk prostate cancer. However, due to higher start-up costs, less reimbursement, and inadequacy in residency training, far fewer radiation facilities are offering BT than external be
{"title":"PO71","authors":"Hong Zhang, Catherine Liu","doi":"10.1016/j.brachy.2023.06.172","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.172","url":null,"abstract":"Purpose High-Dose-Rate Brachytherapy (HDR-BT) is an effective yet under-utilized treatment option for localized prostate cancer. Many studies have shown excellent long-term biochemical-failure-free survival outcomes with limited toxicity from HDR-BT as monotherapy for low- or intermediate-risk prostate cancer. However, due to higher start-up costs, less reimbursement, and inadequacy in residency training, far fewer radiation facilities are offering BT than external beam radiation (EBRT). Here, we performed a single-center, retrospective cohort study to evaluate the travel burdens put on patients who received BT as monotherapy at our high-volume center and if they had chosen external beam radiation close to home for localized prostate cancer. Materials and Methods From 1/1/2019 to 12/31/2022, 69 men were treated with HDR-BT as monotherapy at our brachytherapy center, receiving 27 Gy in 2 fractions, one week apart. Sixty-eight men had low- or intermediate-risk prostate cancer (Table). The travel burden for HDR-BT as monotherapy was estimated by collecting the distance between each patient's home address to our BT center (BT-D). The distance between each patient's home address and the nearest EBRT facility (EBRT-D) was also collected. The total travel burden for EBRT was then calculated, assuming a standard regiment of 28 fractions was used. Results Of the 69 patients who received BT for prostate cancer, the average age was 67.9 years, the overwhelming majority were white (96%), and all had insurance. The median and average EBRT-D were 5.5 and 8.3 miles, respectively. The median and average BT-D were 21 and 37.4 miles, respectively. However, due to the fewer visits required for BT (2 versus 28 trips), the total BT travel burden (median 84 miles, average 150.0 miles) was significantly less than for these patients if they had chosen EBRT instead (median 308 miles, average 462.5 miles) (p<0.01). On average, by choosing BT instead of EBRT, these patients reduced their travel burden by 312.5 miles. Conclusions We observed a significantly decreased overall travel burden for HDR-BT as monotherapy compared with EBRT in our cohort of patients with localized prostate cancer, despite a longer travel distance to our BT center than a nearby EBRT facility. Our study supports that HDR-BT as monotherapy remains a practical and preferred option for patients with localized prostate cancer, not only for its proven safety and efficacy but also decreased overall travel burden compared with definitive EBRT therapy. High-Dose-Rate Brachytherapy (HDR-BT) is an effective yet under-utilized treatment option for localized prostate cancer. Many studies have shown excellent long-term biochemical-failure-free survival outcomes with limited toxicity from HDR-BT as monotherapy for low- or intermediate-risk prostate cancer. However, due to higher start-up costs, less reimbursement, and inadequacy in residency training, far fewer radiation facilities are offering BT than external be","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"107 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":"135434441","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}
Pub Date : 2023-09-01DOI: 10.1016/j.brachy.2023.06.136
Suman Gautam, Alexander F. I Osman, Dylan Richerson, Binod Manandhar, Sharmin Alam, William Y. Song
Purpose The purpose of this work is to develop a voxel-wise dose prediction system using convolutional neural network (CNN) for cervical cancer high-dose-rate (HDR) intracavitary brachytherapy treatment planning with tandem-and-ovoid (T&O) or tandem-and-ring (T&R) applicators. Materials and Methods A 3D U-NET CNN was implemented to generate voxel-wise dose predictions based on high-risk clinical target volume (HRCTV) and organs at risk (OAR) contour information. A multi-institutional cohort of 77 retrospective clinical HDR brachytherapy plans treated to a prescription dose in the range of 4.8-7.0 Gy/fx was used in this study. Those plans were randomly divided into 60%/20%/20% as training, validating, and testing cohorts. Data augmentation techniques like flip diagonally, flip left and right, flipping up and down, and rotating 90 degrees were implemented in the training and validation cohort data to increase the number of plans to 252. The model was trained using the mean-squared loss function, Adam optimization algorithm, a learning rate of 0.001, 250 epochs, and a batch size of 8. The model performance was evaluated on the testing dataset by analyzing the outcomes in terms of maximum dose values and derived dose-volume-histogram (DVH) indices from 3D dose distributions and comparing the generated dose distributions against the ground-truth dose distributions using dose statistics and clinically meaningful dosimetric indices. Results The proposed 3D U-Net model showed competitive accuracy in predicting 3D dose distributions that closely resemble the ground truth dose distributions. The average value of mean absolute error was 0.108±3.617 Gy for HRCTV, 0.074±1.315 Gy for bladder, 0.093±0.981 Gy for rectum, and 0.035±2.789 Gy for sigmoid. The median absolute error was 0.126 Gy for HRCTV, 0.041 Gy for the bladder, 0.0013 Gy for rectum, and 0.019 Gy for sigmoid. Our results showed that the predicted mean D2cc OAR doses in the bladder, rectum, sigmoid were 3.51±1.25, 3.11±1.23 and 4.02±2.23 Gy in comparison to 4.21±1.23, 4.20±1.02, 4.80±1.59 Gy in clinical plans respectively. The predicted D90 of the HRCTV was 6.72±0.99 Gy in comparison with 6.83±1.72 Gy in clinical plans. The predicted maximum dose to bladder, sigmoid, and rectum were 7.51±1.10, 3.81±1.27, 3.61±1.16 Gy in comparison to 7.33±1.03, 4.66±2.06, 4.33±1.75 Gy in clinical plans, respectively, indicating a good potential to predict useful dosimetric indices and facilitate an improvement in brachytherapy treatment workflow. The proposed model needs less than 5 seconds to predict a full 3D dose distribution of 64 × 64 × 64 voxels for any new patient plan, thus making it sufficient for near real-time applications and aid in decision-making in clinic. Conclusions The 3D U-Net model we have implemented demonstrates competitive capability in predicting accurate dose distributions and DVH indices with consistent quality. The proposed model can be used to predict 3D dose distributions for near real-
{"title":"PO35","authors":"Suman Gautam, Alexander F. I Osman, Dylan Richerson, Binod Manandhar, Sharmin Alam, William Y. Song","doi":"10.1016/j.brachy.2023.06.136","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.136","url":null,"abstract":"Purpose The purpose of this work is to develop a voxel-wise dose prediction system using convolutional neural network (CNN) for cervical cancer high-dose-rate (HDR) intracavitary brachytherapy treatment planning with tandem-and-ovoid (T&O) or tandem-and-ring (T&R) applicators. Materials and Methods A 3D U-NET CNN was implemented to generate voxel-wise dose predictions based on high-risk clinical target volume (HRCTV) and organs at risk (OAR) contour information. A multi-institutional cohort of 77 retrospective clinical HDR brachytherapy plans treated to a prescription dose in the range of 4.8-7.0 Gy/fx was used in this study. Those plans were randomly divided into 60%/20%/20% as training, validating, and testing cohorts. Data augmentation techniques like flip diagonally, flip left and right, flipping up and down, and rotating 90 degrees were implemented in the training and validation cohort data to increase the number of plans to 252. The model was trained using the mean-squared loss function, Adam optimization algorithm, a learning rate of 0.001, 250 epochs, and a batch size of 8. The model performance was evaluated on the testing dataset by analyzing the outcomes in terms of maximum dose values and derived dose-volume-histogram (DVH) indices from 3D dose distributions and comparing the generated dose distributions against the ground-truth dose distributions using dose statistics and clinically meaningful dosimetric indices. Results The proposed 3D U-Net model showed competitive accuracy in predicting 3D dose distributions that closely resemble the ground truth dose distributions. The average value of mean absolute error was 0.108±3.617 Gy for HRCTV, 0.074±1.315 Gy for bladder, 0.093±0.981 Gy for rectum, and 0.035±2.789 Gy for sigmoid. The median absolute error was 0.126 Gy for HRCTV, 0.041 Gy for the bladder, 0.0013 Gy for rectum, and 0.019 Gy for sigmoid. Our results showed that the predicted mean D2cc OAR doses in the bladder, rectum, sigmoid were 3.51±1.25, 3.11±1.23 and 4.02±2.23 Gy in comparison to 4.21±1.23, 4.20±1.02, 4.80±1.59 Gy in clinical plans respectively. The predicted D90 of the HRCTV was 6.72±0.99 Gy in comparison with 6.83±1.72 Gy in clinical plans. The predicted maximum dose to bladder, sigmoid, and rectum were 7.51±1.10, 3.81±1.27, 3.61±1.16 Gy in comparison to 7.33±1.03, 4.66±2.06, 4.33±1.75 Gy in clinical plans, respectively, indicating a good potential to predict useful dosimetric indices and facilitate an improvement in brachytherapy treatment workflow. The proposed model needs less than 5 seconds to predict a full 3D dose distribution of 64 × 64 × 64 voxels for any new patient plan, thus making it sufficient for near real-time applications and aid in decision-making in clinic. Conclusions The 3D U-Net model we have implemented demonstrates competitive capability in predicting accurate dose distributions and DVH indices with consistent quality. The proposed model can be used to predict 3D dose distributions for near real-","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"135 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":"135434533","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：