Pub Date : 2023-09-01DOI: 10.1016/j.brachy.2023.06.198
Abigail Dare, Zachary Horne
Purpose To compare dosimetric values for interstitial HDR brachytherapy cases using both manual and inverse planning techniques and refine optimization results for clinical use. Materials and Methods Ten plans for prior interstitial brachytherapy were selected for analysis representing a variety of treatments: Elekta's Venezia applicator with needles (4), Best Medical's Syed/Neblett gynecological template (3), and Best Medical's prostate template (3). Each plan, previously manually optimized (MO), was optimized in Oncentra (Elekta) using both IPSA and HIPO inverse planning algorithms. For the first plan of each type, optimization parameters were iteratively adjusted from comparison to the MO treated plan. The parameters were then saved as a template to apply to future plans of the same type. Dosimetric quantities were recorded for each optimization type for comparison. For the optimized cases, the metrics collected were clinically relevant values representing target coverage and OAR constraints. Results For target coverage (HRCTV D90%), IPSA produced lower coverage on average for Venezia (-15.5%) and Syed (-0.2%) cases when compared to the MO plan and higher for prostate (4.3%). HIPO resulted in higher coverage for Venezia (1.3%) and prostate (1.5%) and lower for Syed (-0.7%). OAR doses were assessed normalized to HRCTV D90% equal to prescription dose. IPSA had lower OAR metrics on average for Syed (-8.3%) and prostate (-3.2%) and higher for Venezia (0.1%). HIPO gave lower OAR metrics for Venezia (-1.9%) and Syed (-4.2%) and higher for prostate (2.2%). Conclusions Overall, HIPO was more consistent in comparable or improved results to the clinically treated MO plan. Treatment planning time for clinical interstitial cases has reduced, and we have adopted a hybrid optimization approach starting with HIPO inverse optimization and then performing manual changes as needed. Future work includes refining optimization parameters to be globally applicable for each treatment type and warrant less manual optimization. To compare dosimetric values for interstitial HDR brachytherapy cases using both manual and inverse planning techniques and refine optimization results for clinical use. Ten plans for prior interstitial brachytherapy were selected for analysis representing a variety of treatments: Elekta's Venezia applicator with needles (4), Best Medical's Syed/Neblett gynecological template (3), and Best Medical's prostate template (3). Each plan, previously manually optimized (MO), was optimized in Oncentra (Elekta) using both IPSA and HIPO inverse planning algorithms. For the first plan of each type, optimization parameters were iteratively adjusted from comparison to the MO treated plan. The parameters were then saved as a template to apply to future plans of the same type. Dosimetric quantities were recorded for each optimization type for comparison. For the optimized cases, the metrics collected were clinically relevant values representing target coverag
{"title":"PO97","authors":"Abigail Dare, Zachary Horne","doi":"10.1016/j.brachy.2023.06.198","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.198","url":null,"abstract":"Purpose To compare dosimetric values for interstitial HDR brachytherapy cases using both manual and inverse planning techniques and refine optimization results for clinical use. Materials and Methods Ten plans for prior interstitial brachytherapy were selected for analysis representing a variety of treatments: Elekta's Venezia applicator with needles (4), Best Medical's Syed/Neblett gynecological template (3), and Best Medical's prostate template (3). Each plan, previously manually optimized (MO), was optimized in Oncentra (Elekta) using both IPSA and HIPO inverse planning algorithms. For the first plan of each type, optimization parameters were iteratively adjusted from comparison to the MO treated plan. The parameters were then saved as a template to apply to future plans of the same type. Dosimetric quantities were recorded for each optimization type for comparison. For the optimized cases, the metrics collected were clinically relevant values representing target coverage and OAR constraints. Results For target coverage (HRCTV D90%), IPSA produced lower coverage on average for Venezia (-15.5%) and Syed (-0.2%) cases when compared to the MO plan and higher for prostate (4.3%). HIPO resulted in higher coverage for Venezia (1.3%) and prostate (1.5%) and lower for Syed (-0.7%). OAR doses were assessed normalized to HRCTV D90% equal to prescription dose. IPSA had lower OAR metrics on average for Syed (-8.3%) and prostate (-3.2%) and higher for Venezia (0.1%). HIPO gave lower OAR metrics for Venezia (-1.9%) and Syed (-4.2%) and higher for prostate (2.2%). Conclusions Overall, HIPO was more consistent in comparable or improved results to the clinically treated MO plan. Treatment planning time for clinical interstitial cases has reduced, and we have adopted a hybrid optimization approach starting with HIPO inverse optimization and then performing manual changes as needed. Future work includes refining optimization parameters to be globally applicable for each treatment type and warrant less manual optimization. To compare dosimetric values for interstitial HDR brachytherapy cases using both manual and inverse planning techniques and refine optimization results for clinical use. Ten plans for prior interstitial brachytherapy were selected for analysis representing a variety of treatments: Elekta's Venezia applicator with needles (4), Best Medical's Syed/Neblett gynecological template (3), and Best Medical's prostate template (3). Each plan, previously manually optimized (MO), was optimized in Oncentra (Elekta) using both IPSA and HIPO inverse planning algorithms. For the first plan of each type, optimization parameters were iteratively adjusted from comparison to the MO treated plan. The parameters were then saved as a template to apply to future plans of the same type. Dosimetric quantities were recorded for each optimization type for comparison. For the optimized cases, the metrics collected were clinically relevant values representing target coverag","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"46 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":"135434534","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.2023.06.207
Irina Vasilievna Horot
Ways of the treatment of non-melanomas skin cancer are still under discussion. Recurrences after different modalities usage are still high. It applies to surgery, external irradiation and brachytherapy. Using brachytherapy, we can achieve very high local doses. Moreover, they can be higher, the lower the volume of irradiation. In this sense, brachytherapy has its own characteristics that greatly distinguish it from other approaches, but there are still many unresolved questions in brachytherapy itself. For example, irradiating the tumor with an application method or with injection applicators into the tumor, how to normalize the dose, adhering to the prescribed restrictions. Purpose The aim of the work was to compare the results of three brachytherapy methods in non melanoma skin cancer. Patients and Methods We work at Microselectron, 30 channels. Planning of the isodose distribution is based on CT scans. 370 patients have been treated since 2012. Essential is the question of how many applicators to use and how to distribute them spatially. We use all available methods - iron needles and flexible applicators for interstitial brachytherapy, as well as application methods with individual masks and individual applicator placement. We use boluses to equalize the dose and the arrangement of applicators in several rows. A change in the location of the applicators changes something in the dose distribution that can be used to improve the distribution. That is, for example, to increase the dose value at the center of the tumor and increase the dose-fall gradient at the edges. When we use the applicator method with an individual mask our doses amounted to 36 Gy, 6 Gy, 6 fractions 5 times per week. The normalization of the dose depends on the tumor size, location and some other parameters. In the case of rigid needles insertion we prescribe 8 Gy twice per week, 4 fractions, total dose is equal to 32 Gy. In the case of intratissue irradiation with flexible applicators the total dose is equal to 42.5 Gy, 5.2 Gy, 8 fractions 5 times per week. Interstitial method is used as a rule in the case of volumetric tumors. Results Using iron needles has several advantages - extraction of needles takes place immediately after the delivery of dose in every fraction. The swelling disappears during one hour after extraction, and wound healing after irradiation happens faster. It is especially significant in treating eyelids. However, all three methods are comparable in results when the dose is properly normalized. Conclusion We came to the conclusion that the choice of the method of irradiation, as well as the normalization of the dose in brachytherapy for non-melanoma skin cancer, depends mainly on the characteristics of the tumor and its location. Ways of the treatment of non-melanomas skin cancer are still under discussion. Recurrences after different modalities usage are still high. It applies to surgery, external irradiation and brachytherapy. Using brachytherapy, we
{"title":"PO106","authors":"Irina Vasilievna Horot","doi":"10.1016/j.brachy.2023.06.207","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.207","url":null,"abstract":"Ways of the treatment of non-melanomas skin cancer are still under discussion. Recurrences after different modalities usage are still high. It applies to surgery, external irradiation and brachytherapy. Using brachytherapy, we can achieve very high local doses. Moreover, they can be higher, the lower the volume of irradiation. In this sense, brachytherapy has its own characteristics that greatly distinguish it from other approaches, but there are still many unresolved questions in brachytherapy itself. For example, irradiating the tumor with an application method or with injection applicators into the tumor, how to normalize the dose, adhering to the prescribed restrictions. Purpose The aim of the work was to compare the results of three brachytherapy methods in non melanoma skin cancer. Patients and Methods We work at Microselectron, 30 channels. Planning of the isodose distribution is based on CT scans. 370 patients have been treated since 2012. Essential is the question of how many applicators to use and how to distribute them spatially. We use all available methods - iron needles and flexible applicators for interstitial brachytherapy, as well as application methods with individual masks and individual applicator placement. We use boluses to equalize the dose and the arrangement of applicators in several rows. A change in the location of the applicators changes something in the dose distribution that can be used to improve the distribution. That is, for example, to increase the dose value at the center of the tumor and increase the dose-fall gradient at the edges. When we use the applicator method with an individual mask our doses amounted to 36 Gy, 6 Gy, 6 fractions 5 times per week. The normalization of the dose depends on the tumor size, location and some other parameters. In the case of rigid needles insertion we prescribe 8 Gy twice per week, 4 fractions, total dose is equal to 32 Gy. In the case of intratissue irradiation with flexible applicators the total dose is equal to 42.5 Gy, 5.2 Gy, 8 fractions 5 times per week. Interstitial method is used as a rule in the case of volumetric tumors. Results Using iron needles has several advantages - extraction of needles takes place immediately after the delivery of dose in every fraction. The swelling disappears during one hour after extraction, and wound healing after irradiation happens faster. It is especially significant in treating eyelids. However, all three methods are comparable in results when the dose is properly normalized. Conclusion We came to the conclusion that the choice of the method of irradiation, as well as the normalization of the dose in brachytherapy for non-melanoma skin cancer, depends mainly on the characteristics of the tumor and its location. Ways of the treatment of non-melanomas skin cancer are still under discussion. Recurrences after different modalities usage are still high. It applies to surgery, external irradiation and brachytherapy. Using brachytherapy, we ","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":"135434209","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.2023.06.212
Juan Wang, Yansong Liang, Zezhou Liu, Hongtao Zhang
There is no one-size-fits-all treatment decision for non-melanoma skin cancer (NMSC) in elderly patients, especially patients over 80 years old with multiple comorbidities. As a minimally invasive technology, iodine-125 seeds interstitial brachytherapy (BT) has been applied to solid tumors of the whole body, because it can offer a better dose distribution, which considered to be an effective, simple and safe alternative for local treatment of cancer. We aimed to explore its safety and efficacy for age 80 or older patient with early primary high-risk NMSC. As a retrospective and monocentric report, we collected 80+ year-old patients with early primary high-risk non-melanoma skin cancer treated by personalized iodine-125 seeds interstitial brachytherapy (PISI-BT) between December 2003 and May 2020. Survival status, efficacy, adverse effects (AEs), cosmetic result, cost were recorded (data cut-off, November 20st 2021). Results Only 9 patients met the criteria, median age was 86 (81-90), 5 of 9 were Eastern Cooperative Oncology Group (ECOG) 1, and each of them suffered from at least one comorbidity. After a median follow-up of 29.3 months (3-99), only 2 patients alive, 6 patients showed complete response (CR), 3 showed partial response(PR), and stable disease(SD), progressive disease(PD) were 0, respectively. No recurrences, disease persistence and AEs were detected during the follow-up and the death causes was irrelevant to NMSC. The cosmetic result of Excellent and Good were 2 and 4, 3 cannot be evaluated. The cost (included in the scope of medical insurance reimbursement) was acceptable. Conclusions PISI-BT could be an alternative in 80+ year-old patients with early primary high-risk NMSC. There is no one-size-fits-all treatment decision for non-melanoma skin cancer (NMSC) in elderly patients, especially patients over 80 years old with multiple comorbidities. As a minimally invasive technology, iodine-125 seeds interstitial brachytherapy (BT) has been applied to solid tumors of the whole body, because it can offer a better dose distribution, which considered to be an effective, simple and safe alternative for local treatment of cancer. We aimed to explore its safety and efficacy for age 80 or older patient with early primary high-risk NMSC. As a retrospective and monocentric report, we collected 80+ year-old patients with early primary high-risk non-melanoma skin cancer treated by personalized iodine-125 seeds interstitial brachytherapy (PISI-BT) between December 2003 and May 2020. Survival status, efficacy, adverse effects (AEs), cosmetic result, cost were recorded (data cut-off, November 20st 2021). Only 9 patients met the criteria, median age was 86 (81-90), 5 of 9 were Eastern Cooperative Oncology Group (ECOG) 1, and each of them suffered from at least one comorbidity. After a median follow-up of 29.3 months (3-99), only 2 patients alive, 6 patients showed complete response (CR), 3 showed partial response(PR), and stable disease(SD), progressi
{"title":"PO111","authors":"Juan Wang, Yansong Liang, Zezhou Liu, Hongtao Zhang","doi":"10.1016/j.brachy.2023.06.212","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.212","url":null,"abstract":"There is no one-size-fits-all treatment decision for non-melanoma skin cancer (NMSC) in elderly patients, especially patients over 80 years old with multiple comorbidities. As a minimally invasive technology, iodine-125 seeds interstitial brachytherapy (BT) has been applied to solid tumors of the whole body, because it can offer a better dose distribution, which considered to be an effective, simple and safe alternative for local treatment of cancer. We aimed to explore its safety and efficacy for age 80 or older patient with early primary high-risk NMSC. As a retrospective and monocentric report, we collected 80+ year-old patients with early primary high-risk non-melanoma skin cancer treated by personalized iodine-125 seeds interstitial brachytherapy (PISI-BT) between December 2003 and May 2020. Survival status, efficacy, adverse effects (AEs), cosmetic result, cost were recorded (data cut-off, November 20st 2021). Results Only 9 patients met the criteria, median age was 86 (81-90), 5 of 9 were Eastern Cooperative Oncology Group (ECOG) 1, and each of them suffered from at least one comorbidity. After a median follow-up of 29.3 months (3-99), only 2 patients alive, 6 patients showed complete response (CR), 3 showed partial response(PR), and stable disease(SD), progressive disease(PD) were 0, respectively. No recurrences, disease persistence and AEs were detected during the follow-up and the death causes was irrelevant to NMSC. The cosmetic result of Excellent and Good were 2 and 4, 3 cannot be evaluated. The cost (included in the scope of medical insurance reimbursement) was acceptable. Conclusions PISI-BT could be an alternative in 80+ year-old patients with early primary high-risk NMSC. There is no one-size-fits-all treatment decision for non-melanoma skin cancer (NMSC) in elderly patients, especially patients over 80 years old with multiple comorbidities. As a minimally invasive technology, iodine-125 seeds interstitial brachytherapy (BT) has been applied to solid tumors of the whole body, because it can offer a better dose distribution, which considered to be an effective, simple and safe alternative for local treatment of cancer. We aimed to explore its safety and efficacy for age 80 or older patient with early primary high-risk NMSC. As a retrospective and monocentric report, we collected 80+ year-old patients with early primary high-risk non-melanoma skin cancer treated by personalized iodine-125 seeds interstitial brachytherapy (PISI-BT) between December 2003 and May 2020. Survival status, efficacy, adverse effects (AEs), cosmetic result, cost were recorded (data cut-off, November 20st 2021). Only 9 patients met the criteria, median age was 86 (81-90), 5 of 9 were Eastern Cooperative Oncology Group (ECOG) 1, and each of them suffered from at least one comorbidity. After a median follow-up of 29.3 months (3-99), only 2 patients alive, 6 patients showed complete response (CR), 3 showed partial response(PR), and stable disease(SD), progressi","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":"135434224","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.2023.06.174
Wiwatchai Sittiwong, Pittaya Dankulchai
Purpose To identify a predictive factor associated with local recurrence in prostate cancer patients receiving HDR brachytherapy. Materials and Methods Localized, non-metastatic prostate cancer patients who were treated with brachytherapy with or without external beam radiation (EBRT) between January 2015 to December 2021 were retrospectively reviewed. HDR monotherapy was prescribed at 19 Gy to prostate while HDR brachytherapy was prescribed at 15 Gy to prostate after EBRT of 45-50 Gy to whole pelvis. Factors to identify a predictor of local recurrence included prostate volume, dominant intraprostatic lesion (DIL) volume, PSA density and DIL-concentrated PSA (DILcPSA). DILcPSA is defined as the PSA density within the area of DIL volume which can be calculated by PSA density multiplied by DIL volume. Baseline patient characteristics and tumor characteristics were reported. Univariate and multivariate analysis were performed to identify factors associated local recurrence by using Cox's regression analysis. Results 32 patients with the median follow up time of 59.2 months were included. The median age of patients was 70 years. Most patients were categorized as unfavorable to very high risk (19 patients, 59.4%); however, most common grade group was grade group 2 (14 patients, 43.7%). Most patients received androgen deprivation therapy (ADT) either by medication or surgical castration (25 patients, 78.1%). The proportion of patients underwent HDR brachytherapy as monotherapy (18 patients, 56.2%) was similar to as a boost (14 patients, 43.8%). For tumor characteristics, most of DILs were located at peripheral zone (28 patients, 87.5%). Median DIL volume and prostate volume were 1.13 ml (95%CI 0.78 to 1.48), and 39.4 ml (95%CI 31.38 to 47.42), respectively. Median PSA density and DILcPSA were 0.30 (95%CI 0.12 to 0.48) and 0.33 (95%CI 0.15 to 0.51), respectively. There were 9 patients developed local recurrence. The rate of 5-year local recurrence-free survival was 68.5%. Among factors selected to predict local recurrence, DILcPSA was found to be significantly associated with local recurrence for both univariate and multivariate Cox's regression analysis with HR of 2.10 (95%CI 1.12 to 27.67) p=0.035 and 2.06 (95%CI 1.09 to 27.41) p 0.039, respectively. Prostate volume, DIL volume and PSA density were found no significant correlation with local recurrence. Conclusions DILcPSA could be a potential predictive factor to predict local recurrence in prostate cancer patients receiving HDR brachytherapy. To identify a predictive factor associated with local recurrence in prostate cancer patients receiving HDR brachytherapy. Localized, non-metastatic prostate cancer patients who were treated with brachytherapy with or without external beam radiation (EBRT) between January 2015 to December 2021 were retrospectively reviewed. HDR monotherapy was prescribed at 19 Gy to prostate while HDR brachytherapy was prescribed at 15 Gy to prostate after EBRT of 45-50 Gy to wh
{"title":"PO73","authors":"Wiwatchai Sittiwong, Pittaya Dankulchai","doi":"10.1016/j.brachy.2023.06.174","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.174","url":null,"abstract":"Purpose To identify a predictive factor associated with local recurrence in prostate cancer patients receiving HDR brachytherapy. Materials and Methods Localized, non-metastatic prostate cancer patients who were treated with brachytherapy with or without external beam radiation (EBRT) between January 2015 to December 2021 were retrospectively reviewed. HDR monotherapy was prescribed at 19 Gy to prostate while HDR brachytherapy was prescribed at 15 Gy to prostate after EBRT of 45-50 Gy to whole pelvis. Factors to identify a predictor of local recurrence included prostate volume, dominant intraprostatic lesion (DIL) volume, PSA density and DIL-concentrated PSA (DILcPSA). DILcPSA is defined as the PSA density within the area of DIL volume which can be calculated by PSA density multiplied by DIL volume. Baseline patient characteristics and tumor characteristics were reported. Univariate and multivariate analysis were performed to identify factors associated local recurrence by using Cox's regression analysis. Results 32 patients with the median follow up time of 59.2 months were included. The median age of patients was 70 years. Most patients were categorized as unfavorable to very high risk (19 patients, 59.4%); however, most common grade group was grade group 2 (14 patients, 43.7%). Most patients received androgen deprivation therapy (ADT) either by medication or surgical castration (25 patients, 78.1%). The proportion of patients underwent HDR brachytherapy as monotherapy (18 patients, 56.2%) was similar to as a boost (14 patients, 43.8%). For tumor characteristics, most of DILs were located at peripheral zone (28 patients, 87.5%). Median DIL volume and prostate volume were 1.13 ml (95%CI 0.78 to 1.48), and 39.4 ml (95%CI 31.38 to 47.42), respectively. Median PSA density and DILcPSA were 0.30 (95%CI 0.12 to 0.48) and 0.33 (95%CI 0.15 to 0.51), respectively. There were 9 patients developed local recurrence. The rate of 5-year local recurrence-free survival was 68.5%. Among factors selected to predict local recurrence, DILcPSA was found to be significantly associated with local recurrence for both univariate and multivariate Cox's regression analysis with HR of 2.10 (95%CI 1.12 to 27.67) p=0.035 and 2.06 (95%CI 1.09 to 27.41) p 0.039, respectively. Prostate volume, DIL volume and PSA density were found no significant correlation with local recurrence. Conclusions DILcPSA could be a potential predictive factor to predict local recurrence in prostate cancer patients receiving HDR brachytherapy. To identify a predictive factor associated with local recurrence in prostate cancer patients receiving HDR brachytherapy. Localized, non-metastatic prostate cancer patients who were treated with brachytherapy with or without external beam radiation (EBRT) between January 2015 to December 2021 were retrospectively reviewed. HDR monotherapy was prescribed at 19 Gy to prostate while HDR brachytherapy was prescribed at 15 Gy to prostate after EBRT of 45-50 Gy to wh","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"25 2 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":"135434362","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.2023.06.127
Pooja Venkatesh, Juhi Purswani, Nicholas Colangelo, Sofia Perez Otero, Nicole Hindman, Stella Lymberis
Purpose Radiation toxicity to female erectile tissue, specifically the bulboclitoral apparatus, has not been previously investigated. This retrospective cohort study aims to demonstrate the feasibility of contouring the bulboclitoris (BC) and evaluate dose received by the BC in patients who underwent interstitial gynecologic brachytherapy for tumors involving the lower vagina and periurethral region. Materials and Methods Patients were treated with HDR brachytherapy between the years 2017 and 2022. All patients underwent IMRT external beam radiotherapy (EBRT) to the pelvis and bilateral inguinal region (45 Gy in 25 fractions) followed by High Dose Rate Ir-192 interstitial brachytherapy using the CT/MR M.A.C. Interstitial Gyn Template in 5 fractions for a total dose of 25 Gy (range, 22.5 - 27.5 Gy). The bulboclitoris (BC) was contoured retrospectively by a radiation oncologist and a pelvic radiologist using T2 MRI sequences fused to the pre-treatment and brachytherapy CT simulation. Superiorly, the BC was defined as inferior to the pubic symphysis and attached to the suspensory ligament of the clitoris. Laterally, the crura extend on either side of the corpus. Inferiorly, the vestibular bulbs flank the urethra and vagina on either side and do not extend posteriorly beyond the vagina. A representative contour of the bulboclitoral apparatus is depicted in Figure 1. Dosimetric data for the BC were calculated using EQD2 assuming an alpha-beta ratio of 3 Gy. Median follow up, local control, and vaginal morbidity using CTCAE version 4.0 for vaginal stenosis and pain scoring of the BC was evaluated. Results Patients had a median age of 65 years (range, 49-73). Three of the five patients had a diagnosis of squamous cell carcinoma of the vagina, one patient had recurrent cervical cancer in the vagina, and one patient had endometrioid adenocarcinoma involving the vagina. All tumors were located in the lower vagina, near the BC and urethra. The high-risk clinical target volume (HR-CTV), bladder, rectum, and urethra were contoured on patient imaging during initial treatment planning. Mean D90 of the HR-CTV was 79.82 Gy (range, 72.2-89.9 Gy), mean D2cc to the bladder was 66.54 Gy (range, 50.0-87.2 Gy), mean D2cc to the rectum was 60.9 Gy (range, 46.9-72.9), and mean D0.1cc to the urethra was 79.28 Gy (range, 53.9-93 Gy). At a median follow up of 19.6 months, all patients had a complete local response. One patient had systemic progression and died of metastatic disease. The mean pre-treatment volume of the bulboclitoris was 16.6 cc (range, 11.9 - 20.9 cc) and at brachytherapy was 12.66 cc (range, 7.3 - 22.1 cc). The mean IMRT dose to the BC was 45.87 Gy (range, 44.79 - 46.66 Gy) and mean HDR dose was 14.02 Gy (range, 11.23 - 18.88 Gy). Assuming an alpha-beta ratio of 3 Gy, mean bulboclitoral D90 EQD2 was 62.93 Gy (range of 58.72 to 67.22 Gy). In the acute period, all patients reported severe pain in the clitoral glans region and dysuria that completely resolved
{"title":"PO26","authors":"Pooja Venkatesh, Juhi Purswani, Nicholas Colangelo, Sofia Perez Otero, Nicole Hindman, Stella Lymberis","doi":"10.1016/j.brachy.2023.06.127","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.127","url":null,"abstract":"Purpose Radiation toxicity to female erectile tissue, specifically the bulboclitoral apparatus, has not been previously investigated. This retrospective cohort study aims to demonstrate the feasibility of contouring the bulboclitoris (BC) and evaluate dose received by the BC in patients who underwent interstitial gynecologic brachytherapy for tumors involving the lower vagina and periurethral region. Materials and Methods Patients were treated with HDR brachytherapy between the years 2017 and 2022. All patients underwent IMRT external beam radiotherapy (EBRT) to the pelvis and bilateral inguinal region (45 Gy in 25 fractions) followed by High Dose Rate Ir-192 interstitial brachytherapy using the CT/MR M.A.C. Interstitial Gyn Template in 5 fractions for a total dose of 25 Gy (range, 22.5 - 27.5 Gy). The bulboclitoris (BC) was contoured retrospectively by a radiation oncologist and a pelvic radiologist using T2 MRI sequences fused to the pre-treatment and brachytherapy CT simulation. Superiorly, the BC was defined as inferior to the pubic symphysis and attached to the suspensory ligament of the clitoris. Laterally, the crura extend on either side of the corpus. Inferiorly, the vestibular bulbs flank the urethra and vagina on either side and do not extend posteriorly beyond the vagina. A representative contour of the bulboclitoral apparatus is depicted in Figure 1. Dosimetric data for the BC were calculated using EQD2 assuming an alpha-beta ratio of 3 Gy. Median follow up, local control, and vaginal morbidity using CTCAE version 4.0 for vaginal stenosis and pain scoring of the BC was evaluated. Results Patients had a median age of 65 years (range, 49-73). Three of the five patients had a diagnosis of squamous cell carcinoma of the vagina, one patient had recurrent cervical cancer in the vagina, and one patient had endometrioid adenocarcinoma involving the vagina. All tumors were located in the lower vagina, near the BC and urethra. The high-risk clinical target volume (HR-CTV), bladder, rectum, and urethra were contoured on patient imaging during initial treatment planning. Mean D90 of the HR-CTV was 79.82 Gy (range, 72.2-89.9 Gy), mean D2cc to the bladder was 66.54 Gy (range, 50.0-87.2 Gy), mean D2cc to the rectum was 60.9 Gy (range, 46.9-72.9), and mean D0.1cc to the urethra was 79.28 Gy (range, 53.9-93 Gy). At a median follow up of 19.6 months, all patients had a complete local response. One patient had systemic progression and died of metastatic disease. The mean pre-treatment volume of the bulboclitoris was 16.6 cc (range, 11.9 - 20.9 cc) and at brachytherapy was 12.66 cc (range, 7.3 - 22.1 cc). The mean IMRT dose to the BC was 45.87 Gy (range, 44.79 - 46.66 Gy) and mean HDR dose was 14.02 Gy (range, 11.23 - 18.88 Gy). Assuming an alpha-beta ratio of 3 Gy, mean bulboclitoral D90 EQD2 was 62.93 Gy (range of 58.72 to 67.22 Gy). In the acute period, all patients reported severe pain in the clitoral glans region and dysuria that completely resolved","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"60 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":"135434382","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.2023.06.184
Christopher Jason Tien, Emily Draeger, Fada Guan, David J. Carlson, Zhe Jay Chen
Purpose In order to develop a robust universal model which can accurately predict tumor control probability (TCP), it is necessary to first explore the sensitivity of the model on its input radiobiological parameters. We propose a methodology to derive population-averaged values of TCP based on a computational “clinical trial” with an enrollment of virtual patients orders of magnitude larger than physically-achievable cohort sizes (∼1 million), each with precisely-known radiobiological parameter values. Materials and Methods Each virtual patient was randomly assigned α and α/β values following a randomized distribution based on a previous study by Wang et al, endorsed by AAPM TG137 and TG265: α to a log-normal distribution function with mean (µ) of 0.15 Gy-1 and standard deviation (σ) of 0.04 Gy-1; α/β to a Gaussian function with µ=3.1 Gy and σ= 0.5 Gy; the initial clonogenic population was a fixed value of 1.6 x 106 (low-risk patient cohort). Next, after establishing the cohort, the TCP was calculated for each patient using the linear-quadratic (LQ) model assuming Poisson statistics for a range of doses from 0 to 140 Gy. The fractional TCP value was compared against a random number generator value to ultimately determine the binary patient outcome (i.e. TCP or fail). This process was repeated for each patient in the trial and the final population-based TCP was calculated by the ratio of successes to the number of patients in the trial. A series of new trials was created with one million patients to test α and α/β dependence with intentional variations in α or α/β values for α values from 0.7 to 0.23 Gy-1 and α/β values from 1.5 to 5.0 Gy. Results A series of 11 TCP curves was generated. For each curve, one million patients were created and assigned values of α, α/β. For the reference cohort using both the Gaussian and log-normal functions, the TCP90% and TCP50% were 89.4 and 68.9 Gy. With only a fixed log-normal α function, TCP90% was 70.3, 84.3, 89.4, 93.1, 101 Gy and TCP50% was 56.4, 65.9, 69.6, 71.8, 77.7 Gy for α/β=1.5, 2.6, 3.1, 3.6, 5 Gy, respectively. With only a fixed Gaussian α/β function, TCP90% was 126.1, 92.3, 74.0, 62.3 53.5 and TCP50% was 114.3, 89.8, 67.4, 56.4, 48.3 Gy for α=0.07, 0.11, 0.15, 0.19, 0.23 Gy-1, respectively. As illustrated in the Figure, larger values of α or smaller α/β ratios shift the TCP curve to lower TCP90% and TCP50%. Additionally, choosing a distribution of α values centered on 0.15 Gy-1 rather than a fixed α=0.15 Gy-1 significantly flattens the slope of the TCP curve, while using a distribution of α/β values produced indistinguishable TCP curves. Conclusions By leveraging the Law of Large Numbers and raw computing power, we were able to create multiple heterogeneous cohorts each containing 1 million virtual patients to generate realistic TCP curves based on previously published distributions of plausible α and α/β values, such as those endorsed by AAPM TG137 and TG265. This virtual clinical trial was able
{"title":"PO83","authors":"Christopher Jason Tien, Emily Draeger, Fada Guan, David J. Carlson, Zhe Jay Chen","doi":"10.1016/j.brachy.2023.06.184","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.184","url":null,"abstract":"Purpose In order to develop a robust universal model which can accurately predict tumor control probability (TCP), it is necessary to first explore the sensitivity of the model on its input radiobiological parameters. We propose a methodology to derive population-averaged values of TCP based on a computational “clinical trial” with an enrollment of virtual patients orders of magnitude larger than physically-achievable cohort sizes (∼1 million), each with precisely-known radiobiological parameter values. Materials and Methods Each virtual patient was randomly assigned α and α/β values following a randomized distribution based on a previous study by Wang et al, endorsed by AAPM TG137 and TG265: α to a log-normal distribution function with mean (µ) of 0.15 Gy-1 and standard deviation (σ) of 0.04 Gy-1; α/β to a Gaussian function with µ=3.1 Gy and σ= 0.5 Gy; the initial clonogenic population was a fixed value of 1.6 x 106 (low-risk patient cohort). Next, after establishing the cohort, the TCP was calculated for each patient using the linear-quadratic (LQ) model assuming Poisson statistics for a range of doses from 0 to 140 Gy. The fractional TCP value was compared against a random number generator value to ultimately determine the binary patient outcome (i.e. TCP or fail). This process was repeated for each patient in the trial and the final population-based TCP was calculated by the ratio of successes to the number of patients in the trial. A series of new trials was created with one million patients to test α and α/β dependence with intentional variations in α or α/β values for α values from 0.7 to 0.23 Gy-1 and α/β values from 1.5 to 5.0 Gy. Results A series of 11 TCP curves was generated. For each curve, one million patients were created and assigned values of α, α/β. For the reference cohort using both the Gaussian and log-normal functions, the TCP90% and TCP50% were 89.4 and 68.9 Gy. With only a fixed log-normal α function, TCP90% was 70.3, 84.3, 89.4, 93.1, 101 Gy and TCP50% was 56.4, 65.9, 69.6, 71.8, 77.7 Gy for α/β=1.5, 2.6, 3.1, 3.6, 5 Gy, respectively. With only a fixed Gaussian α/β function, TCP90% was 126.1, 92.3, 74.0, 62.3 53.5 and TCP50% was 114.3, 89.8, 67.4, 56.4, 48.3 Gy for α=0.07, 0.11, 0.15, 0.19, 0.23 Gy-1, respectively. As illustrated in the Figure, larger values of α or smaller α/β ratios shift the TCP curve to lower TCP90% and TCP50%. Additionally, choosing a distribution of α values centered on 0.15 Gy-1 rather than a fixed α=0.15 Gy-1 significantly flattens the slope of the TCP curve, while using a distribution of α/β values produced indistinguishable TCP curves. Conclusions By leveraging the Law of Large Numbers and raw computing power, we were able to create multiple heterogeneous cohorts each containing 1 million virtual patients to generate realistic TCP curves based on previously published distributions of plausible α and α/β values, such as those endorsed by AAPM TG137 and TG265. This virtual clinical trial was able ","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"43 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":"135434413","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}
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