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PO41 PO41
Pub Date : 2023-09-01 DOI: 10.1016/j.brachy.2023.06.142
Palanikumar Gunasekar, Susan Mathews, Francis V. James, Aswin Kumar, John Joseph, Sharika V. Menon, K.M. Jagathnath Krishna
Purpose Cervical cancer is the second most common cancer among Indian women. Radical chemo-radiotherapy is the standard of care for the majority of patients in India since most patients get diagnosed late and have locally advanced disease. Traditional Manchester system based brachytherapy planning and dose delivery continues to be widely practiced. Cervical cancer with disease extension beyond upper vagina presents a unique problem for brachytherapy dose delivery. Ovoid in tandem in the vagina is considered ‘Non-standard application’ in the traditional Manchester system where a lower dose to ‘Point A’ is accepted respecting the tolerances. Even in the era of image based brachytherapy, the number and position of the source channels limit the extent of dose optimization possible within the various normal tissue tolerances. The Rotterdam applicator, with both Ovoids and vaginal cylinder, offers the possibility of improved dose delivery in this group of patients. The potential dosimetric advantage was tested in this study. Methods Consecutive cervical cancer patients with vaginal disease beyond mid vagina at presentation were selected for Rotterdam Application. All patients had MR imaging in addition to standard CT planning. High Risk target volume (HRCTV) and organs at risk (OAR) were contoured on MR images as per the GEC-ESTRO guidelines and dose optimized plans were generated on Oncentra planning system V4.6. Residual disease in the vagina was part of the HRCTV and the length of vagina to be treated (tandem vaginal loading) was decided by the extent of initial disease involvement. The prescription dose was 8 Gy and dose constraints to OARs were (≤6 Gy/fx) to rectal D2cc and (≤7.5 Gy/fx) to the bladder D2cc (Subir Nag HDR BT dosimetry data). Two sets of treatment plans were generated for each application 1) with central tandem loading only (IUT PLAN) and 2) Rotterdam plan where ovoids were loaded in addition to central tandem. The HRCTV D90, D2cc Bladder, D2cc Rectum were documented and compared between the two plans. Data was analyzed statistically using paired t-test (normally distributed) or Wilcoxon signed rank test (Non-normal). A p-value < 0.05 is considered to be statistically significant. Results Between 1st January 2021 and 30th June 2022, 24 patients were eligible for Rotterdam application. However, applicator placement was not feasible in 6 patients (25%) with severe upper vaginal narrowing. MR image based plans were generated for 31 applications. The mean age of the patients included in the study was 59 years. Stage wise distribution was as follows IIB-3, IIIB-4, IIIC1-4, IIIC2-2, & IVA-5. At the time of brachytherapy, 10 patients had minimal residual disease involving cervix and upper vagina. None of the patients had residual disease involving lower vagina. The mean HRCTV volume was 30cc (range- 14.29 cc- 51.92cc). The prescription goal of 8Gy or greater was achieved in 18 Rotterdam applications while with standard loading, 12 applicat
子宫颈癌是印度妇女中第二大常见癌症。根治性化疗放疗是印度大多数患者的标准治疗方法,因为大多数患者诊断较晚,局部疾病进展较晚。传统的基于曼彻斯特系统的近距离治疗计划和剂量递送继续被广泛实践。宫颈癌的疾病延伸到上阴道提出了一个独特的问题,近距离治疗剂量的交付。在传统的曼彻斯特系统中,卵形在阴道内串联被认为是“非标准应用”,在尊重耐受性的情况下,对“a点”的较低剂量是可以接受的。即使在基于图像的近距离放射治疗时代,源通道的数量和位置限制了在各种正常组织耐受范围内可能的剂量优化程度。Rotterdam应用器,同时具有卵状体和阴道筒,为这组患者提供了改善剂量递送的可能性。本研究测试了潜在的剂量学优势。方法选择连续就诊时阴道病变超过阴道中部的宫颈癌患者进行鹿特丹试验。除了标准的CT计划外,所有患者都进行了MR成像。高危靶体积(HRCTV)和危险器官(OAR)按照GEC-ESTRO指南在MR图像上绘制轮廓,并在Oncentra计划系统V4.6上生成剂量优化计划。阴道内残留的疾病是HRCTV的一部分,待治疗的阴道长度(串联阴道负荷)由最初疾病累及的程度决定。处方剂量为8 Gy, OARs对直肠D2cc的剂量限制为(≤6 Gy/fx),对膀胱D2cc的剂量限制为(≤7.5 Gy/fx) (Subir Nag HDR BT剂量学数据)。每个应用产生两套治疗方案:1)仅中心串联加载(IUT计划)和2)在中心串联外同时加载卵泡的鹿特丹计划。记录两种方案的HRCTV D90、膀胱D2cc、直肠D2cc并进行比较。数据采用配对t检验(正态分布)或Wilcoxon符号秩检验(非正态分布)进行统计学分析。p值< 0.05被认为具有统计学意义。在2021年1月1日至2022年6月30日期间,24名患者符合鹿特丹申请条件。然而,有6例(25%)上阴道严重狭窄的患者不能放置涂抹器。为31个应用程序生成了基于MR图像的平面图。研究中患者的平均年龄为59岁。分期分布如下:IIB-3、IIIB-4、IIIC1-4、IIIC2-2、IVA-5。在近距离治疗时,10例患者有轻微残留病变累及宫颈和上阴道。所有患者均无下阴道残留病变。HRCTV平均容积为30cc(范围- 14.29 cc- 51.92cc)。在18个鹿特丹应用程序中达到了8Gy或更大的处方目标,而在标准负载下,12个应用程序达到了目标。HRCTV D90在7个鹿特丹和8个标准应用中>7Gy,在6个鹿特丹和8个标准应用中>6Gy。在标准方案下,7次鹿特丹和8次标准应用的剂量为7Gy, 6次鹿特丹和8次标准应用的剂量>6Gy。在标准方案下,3次应用剂量<6Gy。对于30cc的HRCTV,鹿特丹方案的最低HRCTV D90为6.3 Gy。两组的平均D90 HRCTV (7.1Gy vs. 7.7Gy)差异有统计学意义(p < 0.001)。平均D2cc膀胱被发现与鹿特丹涂抹器明显更好,然而,平均D2cc直肠在两种方案之间没有统计学上的显著差异。鹿特丹涂抹器提供了更大的优化可能性,从而提高HRCTV剂量与标准宫内和串联应用宫颈癌患者的阴道累及。然而,由于解剖学限制,鹿特丹涂抹器放置在一部分患者(约25%)中是不可行的。
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引用次数: 0
PO118 PO118
Pub Date : 2023-09-01 DOI: 10.1016/j.brachy.2023.06.219
Moti Raj Paudel, Elizabeth A. Barnes, Mohammad Kazem, Amandeep S. Taggar
Purpose There has been increased use of surface mould brachytherapy (SMBT) for treating superficial skin lesions located over curved surface and at locations where a sharp dose fall-off is required. We describe our clinical workflow, dosimetry and initial clinical outcome of treating extramammary Paget's disease (EMPD) using SMBT with 3D printed custom applicator. Materials and Methods CT images acquired with and without a thin metal wire were used for delineating target extent to aid contouring gross disease and designing 1cm thick applicator, respectively, in MIM treatment planning system (MIM Software Inc., Cleveland, OH, USA). CTV was delineated on CT images aided by clinical exam and a uniform lateral margin of 7mm was applied to define target. The standard triangle language (STL) files for the applicator and target were generated and further processed in Autodesk Inventor 2021, Autodesk MeshMixer 2017, and Autodesk MeshEnabler 2021 (Autodesk, Inc. San Rafael, California, USA) to design the applicator. Customized catheter positioning regarding spacing and depth from the skin surface (5-7mm, depending upon the patient anatomy) were designed to cover the target volume and minimize dose to organs at risk (OAR). Applicators were then 3D printed using the Accura ClearVue, a USP class VI transparent resin. Plastic catheters were inserted in the applicator and QA test completed to ensure a safe radiation source delivery before using them to acquire planning CT images. Treatment plans were generated with a uniform prescription (Rx) of 42.5Gy in 10 daily fractions prescribed at the target surface with the aim of Target D90%>35Gy and maximum surface dose (defined by D0.3cc) <130% of Rx. We present initial experience, local control, toxicity and cosmesis results for first five EMPD patients treated with our customized SMBT workflow. Results Median patient age was 77yrs (range 66-94), and 3 were female 2 male. All patients presented with characteristic expanding erythematous plaques with typical histopathology and supportive immunohistochemical and clinical findings for EMPD. Median follow-up was 13.3 months (range 1.5-33.4). Mean Target D90 was 34.5 Gy (range 31.7-36), mean Target D0.1cc 53.1 Gy (range 46.2-58.4), mean Target D0.3cc 51.3 Gy (range 45.3-56.4), and mean Target D0.5cc 50.3 Gy (range 44.9-55.4). Treatment was well tolerated, with complete response in 5/5 patients and marginal relapse in 1 patient (Figure 1) which was outside of the treatment field at 13.6 months post-treatment. Acute dermatitis grade 3 was noted in 4 patients with resolution at mean of 49.2 days (range 44-54) and late toxicity hypopigmentation (grade 1; 3 patients) and telangiectasia (grade 1; 1 patient) was noted in a subset of patients treated. Conclusions SMBT was successfully planned and delivered for EMPD using 3D printed custom applicators. Excellent target coverage was achieved while minimizing dose to OAR, and toxicity and cosmesis rates were good to excellent. The
目的:表面霉菌近距离治疗(SMBT)越来越多地用于治疗位于曲面上的浅表皮肤病变和需要急剧剂量下降的位置。我们描述了我们的临床工作流程,剂量学和使用3D打印定制涂抹器SMBT治疗乳腺外佩吉特病(EMPD)的初步临床结果。材料和方法在MIM治疗计划系统(MIM Software Inc., Cleveland, OH, USA)中,分别使用带和不带细金属丝的CT图像来划定目标范围,以帮助勾画大体疾病,并设计1cm厚的涂药器。在临床检查的辅助下,在CT图像上圈定CTV,并以7mm的均匀侧缘确定靶区。应用程序和目标的标准三角语言(STL)文件在Autodesk Inventor 2021、Autodesk MeshMixer 2017和Autodesk MeshEnabler 2021 (Autodesk, Inc.)中生成并进一步处理。San Rafael, California, USA)设计施药器。根据距离皮肤表面的间隔和深度(5-7mm,取决于患者的解剖结构)定制导管定位,以覆盖目标体积并将危及器官(OAR)的剂量降至最低。然后使用Accura ClearVue (USP级VI透明树脂)3D打印涂抹器。在使用塑料导管获取规划CT图像之前,在涂抹器中插入塑料导管并完成QA测试以确保辐射源的安全输送。制定治疗方案的统一处方(Rx)为42.5Gy,分10个日分在靶表面开处方,目标D90%>35Gy,最大表面剂量(D0.3cc定义)35Gy,最大表面剂量(D0.3cc定义)< Rx的130%。我们为前5名接受我们定制的SMBT工作流程治疗的EMPD患者提供初始经验、局部控制、毒性和美容结果。患者中位年龄为77岁(66-94岁),其中女性3例,男性2例。所有患者均表现为特征性的扩张性红斑斑块,具有典型的组织病理学和支持性免疫组织化学和EMPD的临床表现。中位随访时间为13.3个月(1.5-33.4个月)。平均目标D90为34.5 Gy(范围31.7-36),平均目标D0.1cc 53.1 Gy(范围46.2-58.4),平均目标D0.3cc 51.3 Gy(范围45.3-56.4),平均目标D0.5cc 50.3 Gy(范围44.9-55.4)。治疗耐受性良好,5/5患者完全缓解,1例患者在治疗后13.6个月出现治疗范围外的边缘复发(图1)。4例患者出现急性皮炎3级,平均缓解时间为49.2天(范围44-54天),晚期毒性色素减退(1级;3例患者)和毛细血管扩张(1级;1例患者)在接受治疗的患者中被注意到。SMBT使用3D打印定制涂抹器成功规划并交付给EMPD。在对OAR的最小剂量下,达到了极好的靶覆盖率,毒性和美容率从好到优。
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引用次数: 0
PO24 PO24
Pub Date : 2023-09-01 DOI: 10.1016/j.brachy.2023.06.125
Marc Morcos, James McCulloch, Gabi Quintana, Marco Martinez, Mayra Gonzalez-Ng, Yonatan Weiss
Purpose To evaluate the dosimetric impact of bladder fill change between the time of simulation and treatment delivery. Materials and Methods This dosimetric study was completed with 10 individual high-dose-rate brachytherapy implants for cervical cancer patients (7 Gy/fx). Eight implants were performed with the Venezia and two with the Geneva (Elekta Brachy, Veenendaal, The Netherlands). An average of 8.0±1.8 interstitial needles were used. Each implant was imaged at two time point (T0 & T1): once the implant was completed (CT, T0) and approximately an hour later (MR, T1). For this study, optimized treatment plans were generated using the T0 scan. Organs at risk were also contoured on the T1 scan and the unmodified original plan was then applied to the new anatomy (re-digitized, but same dwell times) to assess the impact of anatomical changes to the dosimetrics. EQD2 D2cc for all OARs was calculated assuming an alpha-beta ratio of 3 Gy and a prescription dose of 7 Gy per fraction. Results The mean ± SD bladder fill volume at time, T0, was 222±113 cm3. The bladder fill increased between -100 and +225 cm3 at T1. Changes in EQD2 D2cc to the bladder, rectum, sigmoid and bowel between T0 and T1 are plotted in Figure 2. The impact on EQD2 D2cc changes due to increases in bladder fill volume correlates highly for sigmoid (-0.75), and weakly for bladder (+0.31) and bowel (-0.20). For the rectum, EQD2 D2cc changes are negligibly correlated with respect to bladder fill changes. Conclusions Increases in bladder volume tend to decrease GI (rectum, sigmoid, bowel) OAR doses while increasing dose to the bladder. Ensuring the bladder fill does not decrease at the time of treatment is paramount for protecting GI OARs which have much lower dose limits. Increases in bladder volume should be weighed against the remaining dose tolerance budget for the bladder. Future work will involve acquire more data which may enable the development of quantitative model for predicting patient-specific dosimetric changes based on bladder fill changes. To evaluate the dosimetric impact of bladder fill change between the time of simulation and treatment delivery. This dosimetric study was completed with 10 individual high-dose-rate brachytherapy implants for cervical cancer patients (7 Gy/fx). Eight implants were performed with the Venezia and two with the Geneva (Elekta Brachy, Veenendaal, The Netherlands). An average of 8.0±1.8 interstitial needles were used. Each implant was imaged at two time point (T0 & T1): once the implant was completed (CT, T0) and approximately an hour later (MR, T1). For this study, optimized treatment plans were generated using the T0 scan. Organs at risk were also contoured on the T1 scan and the unmodified original plan was then applied to the new anatomy (re-digitized, but same dwell times) to assess the impact of anatomical changes to the dosimetrics. EQD2 D2cc for all OARs was calculated assuming an alpha-beta ratio of 3 Gy and a prescription dose o
目的评价模拟治疗时间与给药时间膀胱填充变化对剂量学的影响。材料和方法本剂量学研究采用10例宫颈癌患者个体高剂量率近距离放射治疗植入物(7 Gy/fx)完成。使用Venezia进行8次植入,使用Geneva (Elekta Brachy, Veenendaal,荷兰)进行2次植入。平均使用8.0±1.8根间质针。每个种植体在两个时间点(T0和T1)成像:种植体完成后(CT, T0)和大约一小时后(MR, T1)。在本研究中,使用T0扫描生成优化的治疗方案。在T1扫描中也勾画出危险器官的轮廓,然后将未经修改的原始计划应用于新的解剖结构(重新数字化,但停留时间相同),以评估解剖变化对剂量学的影响。假设α - β比为3 Gy,处方剂量为每组分7 Gy,计算所有桨的EQD2 D2cc。结果T0时膀胱填充体积平均值±SD为222±113 cm3。T1时膀胱充盈在-100至+225 cm3之间增加。T0和T1期间膀胱、直肠、乙状结肠和肠道EQD2 D2cc的变化如图2所示。乙状结肠填充量增加对EQD2 D2cc变化的影响与乙状结肠高度相关(-0.75),与膀胱(+0.31)和肠道(-0.20)相关性较弱。对于直肠,EQD2 D2cc变化与膀胱充盈变化的相关性可以忽略不计。结论膀胱体积增大,可降低胃肠道(直肠、乙状结肠、肠道)OAR剂量,增加膀胱剂量。确保膀胱填充物在治疗时不会减少,对于保护GI OARs至关重要,因为GI OARs的剂量限制要低得多。膀胱容量的增加应与膀胱的剩余剂量耐受预算相权衡。未来的工作将包括获取更多的数据,这可能使定量模型的发展能够预测基于膀胱填充变化的患者特异性剂量学变化。目的:评价模拟时间与治疗时间之间膀胱充盈变化对剂量学的影响。这项剂量学研究是通过10例宫颈癌患者个体高剂量率近距离放射治疗植入物(7 Gy/fx)完成的。使用Venezia进行8次植入,使用Geneva (Elekta Brachy, Veenendaal,荷兰)进行2次植入。平均使用8.0±1.8根间质针。每个种植体在两个时间点(T0和T1)成像:种植体完成后(CT, T0)和大约一小时后(MR, T1)。在本研究中,使用T0扫描生成优化的治疗方案。在T1扫描中也勾画出危险器官的轮廓,然后将未经修改的原始计划应用于新的解剖结构(重新数字化,但停留时间相同),以评估解剖变化对剂量学的影响。假设α - β比为3 Gy,处方剂量为每组分7 Gy,计算所有桨的EQD2 D2cc。T0时膀胱填充体积平均值±SD为222±113 cm3。T1时膀胱充盈在-100至+225 cm3之间增加。T0和T1期间膀胱、直肠、乙状结肠和肠道EQD2 D2cc的变化如图2所示。乙状结肠填充量增加对EQD2 D2cc变化的影响与乙状结肠高度相关(-0.75),与膀胱(+0.31)和肠道(-0.20)相关性较弱。对于直肠,EQD2 D2cc变化与膀胱充盈变化的相关性可以忽略不计。膀胱体积的增加往往会减少胃肠道(直肠、乙状结肠、肠道)桨叶剂量,而增加膀胱剂量。确保膀胱填充物在治疗时不会减少,对于保护GI OARs至关重要,因为GI OARs的剂量限制要低得多。膀胱容量的增加应与膀胱的剩余剂量耐受预算相权衡。未来的工作将包括获取更多的数据,这可能使定量模型的发展能够预测基于膀胱填充变化的患者特异性剂量学变化。
{"title":"PO24","authors":"Marc Morcos, James McCulloch, Gabi Quintana, Marco Martinez, Mayra Gonzalez-Ng, Yonatan Weiss","doi":"10.1016/j.brachy.2023.06.125","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.125","url":null,"abstract":"Purpose To evaluate the dosimetric impact of bladder fill change between the time of simulation and treatment delivery. Materials and Methods This dosimetric study was completed with 10 individual high-dose-rate brachytherapy implants for cervical cancer patients (7 Gy/fx). Eight implants were performed with the Venezia and two with the Geneva (Elekta Brachy, Veenendaal, The Netherlands). An average of 8.0±1.8 interstitial needles were used. Each implant was imaged at two time point (T0 & T1): once the implant was completed (CT, T0) and approximately an hour later (MR, T1). For this study, optimized treatment plans were generated using the T0 scan. Organs at risk were also contoured on the T1 scan and the unmodified original plan was then applied to the new anatomy (re-digitized, but same dwell times) to assess the impact of anatomical changes to the dosimetrics. EQD2 D2cc for all OARs was calculated assuming an alpha-beta ratio of 3 Gy and a prescription dose of 7 Gy per fraction. Results The mean ± SD bladder fill volume at time, T0, was 222±113 cm3. The bladder fill increased between -100 and +225 cm3 at T1. Changes in EQD2 D2cc to the bladder, rectum, sigmoid and bowel between T0 and T1 are plotted in Figure 2. The impact on EQD2 D2cc changes due to increases in bladder fill volume correlates highly for sigmoid (-0.75), and weakly for bladder (+0.31) and bowel (-0.20). For the rectum, EQD2 D2cc changes are negligibly correlated with respect to bladder fill changes. Conclusions Increases in bladder volume tend to decrease GI (rectum, sigmoid, bowel) OAR doses while increasing dose to the bladder. Ensuring the bladder fill does not decrease at the time of treatment is paramount for protecting GI OARs which have much lower dose limits. Increases in bladder volume should be weighed against the remaining dose tolerance budget for the bladder. Future work will involve acquire more data which may enable the development of quantitative model for predicting patient-specific dosimetric changes based on bladder fill changes. To evaluate the dosimetric impact of bladder fill change between the time of simulation and treatment delivery. This dosimetric study was completed with 10 individual high-dose-rate brachytherapy implants for cervical cancer patients (7 Gy/fx). Eight implants were performed with the Venezia and two with the Geneva (Elekta Brachy, Veenendaal, The Netherlands). An average of 8.0±1.8 interstitial needles were used. Each implant was imaged at two time point (T0 & T1): once the implant was completed (CT, T0) and approximately an hour later (MR, T1). For this study, optimized treatment plans were generated using the T0 scan. Organs at risk were also contoured on the T1 scan and the unmodified original plan was then applied to the new anatomy (re-digitized, but same dwell times) to assess the impact of anatomical changes to the dosimetrics. EQD2 D2cc for all OARs was calculated assuming an alpha-beta ratio of 3 Gy and a prescription dose o","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"30 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":"135434219","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}
引用次数: 0
PO49 PO49
Pub Date : 2023-09-01 DOI: 10.1016/j.brachy.2023.06.150
Jessica Cruttenden, Christopher W. Weil, Lindsay M. Burt, Gita Suneja, David K. Gaffney, Cristina M. DeCesaris
Purpose To investigate practice patterns in adjuvant radiation (RT) delivery for patients with FIGO stage II endometrioid endometrial adenocarcinoma treated between 2004-2019. Materials and Methods The National Cancer Database (NCDB) was queried to review patients diagnosed between 2004-2019 with FIGO stage II endometrioid endometrial adenocarcinoma who underwent total hysterectomy and bilateral salpingo-oophorectomy (TH/BSO) and surgical staging. Multivariate regression analysis (MVA) was used to identify prognostic variables for adjuvant RT and RT omission. Results A total of 18,798 patients met inclusion criteria. Median follow-up was 6 years. Median age was 60 years. Twelve percent of patients received chemotherapy (CHT), and 68% received adjuvant RT. Of the study population, 19% received external beam radiation (EBRT) alone, 25% received vaginal brachytherapy (VBT) alone, and 24% received EBRT+VBT. Of those who received CHT, 35% received CHT alone whereas 25% also received EBRT alone, 22% received VBT alone, and 18% received EBRT+VBT. Use of adjuvant RT, including EBRT, VBT, and EBRT+VBT, increased over time, and EBRT+VBT was the most common treatment in 2019 (34% vs 23% in 2004; see Figure 1). On MVA, treatment at a community hospital (OR 1.8, p<0.001) or in the Midwest (OR 1.2, p=0.02), receipt of single agent chemotherapy (OR 6.9, p<0.001), LVSI+ (OR 1.4, p<0.001), and positive surgical margins (OR 1.8, p<0.001) were associated with increased likelihood of receiving any EBRT. No factors were significantly associated with an increased likelihood of receiving any VBT. Age >60 years old (OR 0.86, p=0.02), treatment at a community hospital (OR 0.41, p<0.001), distance from a treatment center >50 miles (OR 0.72, p<0.001), and grade 2 (OR 0.86, p=0.02) or 3 (OR 0.80, p=0.01) disease were associated with decreased likelihood of receiving VBT. Regionally, patients treated in the Midwest (OR 0.84, p=0.02), South (OR 0.54, p<0.001), or West (OR 0.52, p<0.001) were less likely to have received VBT compared to those in the Northeast. Black race (OR 1.2, p=0.03), treatment at a community hospital (OR 1.4, p=0.04), treatment in the South (OR 2.2, p<0.001) or West (OR 2.1, p<0.001), distance from a treatment center >50 miles (OR 1.5, p<0.001), and grade 2 (OR 1.2, p<0.001) or 3 (OR 1.3, p=0.01) disease were associated with an increased likelihood of RT omission. In contrast, receipt of single agent chemotherapy (OR 0.14, p<0.01), >50% myometrial invasion (OR 0.58, p<0.001), and positive surgical margins (OR 0.66, p=0.03) were associated with a decreased likelihood of RT omission. Conclusions Treatment guidelines for FIGO stage II endometrioid endometrial carcinoma support a variety of adjuvant treatment options with little data to direct selection of adjuvant therapy after surgery. Use of adjuvant RT has increased over the years, particularly the use of both EBRT+VBT. Patient-related factors such as race, region, and distance from treatment center were
目的探讨2004-2019年FIGO II期子宫内膜样子宫内膜腺癌患者辅助放疗(RT)的实践模式。材料与方法通过查询国家癌症数据库(NCDB),回顾2004-2019年诊断为FIGO II期子宫内膜样子宫内膜腺癌并接受全子宫切除术和双侧输卵管-卵巢切除术(TH/BSO)和手术分期的患者。多变量回归分析(MVA)用于确定辅助RT和遗漏RT的预后变量。结果18798例患者符合纳入标准。中位随访时间为6年。中位年龄为60岁。12%的患者接受了化疗(CHT), 68%的患者接受了辅助放疗。在研究人群中,19%的患者单独接受了外束放疗(EBRT), 25%的患者单独接受了阴道近距离放疗(VBT), 24%的患者接受了EBRT+VBT。在接受CHT治疗的患者中,35%单独接受CHT治疗,25%同时接受EBRT治疗,22%单独接受VBT治疗,18%接受EBRT+VBT治疗。辅助放疗(包括EBRT、VBT和EBRT+VBT)的使用随着时间的推移而增加,EBRT+VBT是2019年最常见的治疗方法(34%比2004年的23%;见图1)。在MVA,社区医院治疗(或1.8,p60岁(或0.86,p = 0.02),在一个社区医院治疗(p50英里或0.41(或0.72 p50英里(或1.5,p50%子宫肌层的入侵(或0.58,p60岁(或0.86,p = 0.02),在一个社区医院治疗(p50英里或0.41(或0.72 p50英里(或1.5,p50%子宫肌层的入侵(或0.58,p < 0.001),和积极的外科利润率(或0.66,p = 0.03)与RT遗漏的可能性降低。FIGO II期子宫内膜样子宫内膜癌的治疗指南支持多种辅助治疗方案,但很少有数据可以指导术后辅助治疗的选择。近年来,辅助放疗的使用有所增加,尤其是EBRT+VBT的使用。患者相关因素(如种族、地区和距离治疗中心的距离)与遗漏RT相关,而肿瘤相关危险因素(如手术切缘阳性、LVSI和肌层浸润)与使用EBRT相关。辅助放疗的使用因地区而异,尤其是VBT的使用。辅助治疗的最佳选择仍不确定;然而,识别这些模式可以帮助指导研究更明确地指导辅助治疗指南,并可能有助于识别辅助放疗实践中的差距或偏差。
{"title":"PO49","authors":"Jessica Cruttenden, Christopher W. Weil, Lindsay M. Burt, Gita Suneja, David K. Gaffney, Cristina M. DeCesaris","doi":"10.1016/j.brachy.2023.06.150","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.150","url":null,"abstract":"Purpose To investigate practice patterns in adjuvant radiation (RT) delivery for patients with FIGO stage II endometrioid endometrial adenocarcinoma treated between 2004-2019. Materials and Methods The National Cancer Database (NCDB) was queried to review patients diagnosed between 2004-2019 with FIGO stage II endometrioid endometrial adenocarcinoma who underwent total hysterectomy and bilateral salpingo-oophorectomy (TH/BSO) and surgical staging. Multivariate regression analysis (MVA) was used to identify prognostic variables for adjuvant RT and RT omission. Results A total of 18,798 patients met inclusion criteria. Median follow-up was 6 years. Median age was 60 years. Twelve percent of patients received chemotherapy (CHT), and 68% received adjuvant RT. Of the study population, 19% received external beam radiation (EBRT) alone, 25% received vaginal brachytherapy (VBT) alone, and 24% received EBRT+VBT. Of those who received CHT, 35% received CHT alone whereas 25% also received EBRT alone, 22% received VBT alone, and 18% received EBRT+VBT. Use of adjuvant RT, including EBRT, VBT, and EBRT+VBT, increased over time, and EBRT+VBT was the most common treatment in 2019 (34% vs 23% in 2004; see Figure 1). On MVA, treatment at a community hospital (OR 1.8, p<0.001) or in the Midwest (OR 1.2, p=0.02), receipt of single agent chemotherapy (OR 6.9, p<0.001), LVSI+ (OR 1.4, p<0.001), and positive surgical margins (OR 1.8, p<0.001) were associated with increased likelihood of receiving any EBRT. No factors were significantly associated with an increased likelihood of receiving any VBT. Age >60 years old (OR 0.86, p=0.02), treatment at a community hospital (OR 0.41, p<0.001), distance from a treatment center >50 miles (OR 0.72, p<0.001), and grade 2 (OR 0.86, p=0.02) or 3 (OR 0.80, p=0.01) disease were associated with decreased likelihood of receiving VBT. Regionally, patients treated in the Midwest (OR 0.84, p=0.02), South (OR 0.54, p<0.001), or West (OR 0.52, p<0.001) were less likely to have received VBT compared to those in the Northeast. Black race (OR 1.2, p=0.03), treatment at a community hospital (OR 1.4, p=0.04), treatment in the South (OR 2.2, p<0.001) or West (OR 2.1, p<0.001), distance from a treatment center >50 miles (OR 1.5, p<0.001), and grade 2 (OR 1.2, p<0.001) or 3 (OR 1.3, p=0.01) disease were associated with an increased likelihood of RT omission. In contrast, receipt of single agent chemotherapy (OR 0.14, p<0.01), >50% myometrial invasion (OR 0.58, p<0.001), and positive surgical margins (OR 0.66, p=0.03) were associated with a decreased likelihood of RT omission. Conclusions Treatment guidelines for FIGO stage II endometrioid endometrial carcinoma support a variety of adjuvant treatment options with little data to direct selection of adjuvant therapy after surgery. Use of adjuvant RT has increased over the years, particularly the use of both EBRT+VBT. Patient-related factors such as race, region, and distance from treatment center were ","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"105 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":"135434359","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}
引用次数: 0
PO100 PO100
Pub Date : 2023-09-01 DOI: 10.1016/j.brachy.2023.06.201
Juan Wang, Hongtao Zhang, Yansong Liang, Jianmin Li
Purpose To study the radiation dose rate and effective dose in ambient environment due to 1I seed implantation in the treatment of the patients suffering abdominal and pelvic tumors, so as to provide reference for occupational protection of different groups. Materials and Methods Within 24hours after operation , the radiation dose rate to 42 patients with abdominal and pelvic tumor with 125I seed implantation was monitored by using pocket dosimeter. The relationships between the total activity in the implanted particles and the measured dose rate, as well as hetween the implanted depth and the dose rate under the standard activity, were obtained by curve fitting. According to the formula, the relationship between the dose rate and the warning time was calculated. Results The dose rates at 30 cm , 50 cm and00 cm of vertical particle implantation site were (6.92+2. 87) , (4. 10+1. 62) and (1.30+0. 48) u.Sv/h. respectively (X'= 73. 71, P<0. 05). The dose rates on the left and right sides were (0. 378+0. 156) and (0.384+0. 153) Sv/h at 30 cm, (0. 170+0. 089) and (0.17+0. 086) uSv/h at 50 cm, (0. 039 +0. 014) and (0. 043+0.017) Sv/h at 100 cm, respectively (X'= 76. 19, 76. 33, P<0. 05). There was a linear relationship between the dose rate at the vertical particle implantation site and the total activity in the implanted particles, and between the dose rate and the implantation depth under the standard activity. The relationship between the warning time and the dose rate to adults in the same bed, co-workers , minors in the same bed and pregnant women were as follows: t (d) = -106. 616+83. 779lnD (t) , t (d) = 26. 556+85. 933lnD (t), t (d) = 3.088 + 85. 017InD (t). Conclusions After's I seed implantation, the radiation dose in the ambient environment is low, ensuring the radiation safety; and the measured dose rate decreases with the decrease in the total activity in the implanted particle and the increase in the implantation depth; at the same time, the warning time for different groups is calculated according to the measured dose rate or the total activity in the implanted particle and the depth of the implanted particle, so as to carry out individualized protection. To study the radiation dose rate and effective dose in ambient environment due to 1I seed implantation in the treatment of the patients suffering abdominal and pelvic tumors, so as to provide reference for occupational protection of different groups. Within 24hours after operation , the radiation dose rate to 42 patients with abdominal and pelvic tumor with 125I seed implantation was monitored by using pocket dosimeter. The relationships between the total activity in the implanted particles and the measured dose rate, as well as hetween the implanted depth and the dose rate under the standard activity, were obtained by curve fitting. According to the formula, the relationship between the dose rate and the warning time was calculated. The dose rates at 30 cm , 50 cm and00 cm of vertical
目的研究1I粒子植入治疗腹盆腔肿瘤患者的放射剂量率和环境有效剂量,为不同人群的职业防护提供参考。材料与方法应用袖珍剂量计监测42例经125I粒子植入的腹部及盆腔肿瘤术后24h内的放射剂量率。通过曲线拟合得到注入粒子的总活度与测量剂量率之间的关系,以及标准活度下注入深度与剂量率之间的关系。根据公式,计算了剂量率与预警时间的关系。结果30 cm、50 cm和00 cm垂直粒子植入部位的剂量率分别为(6.92+2)。87), (4);10 + 1。62)和(1.30+0)。48) u.Sv / h。(X'= 73)。71, P < 0。05). 左右两侧的剂量率分别为(0。378 + 0。(0.384+0。30cm时,Sv/h (0.53);170 + 0。089)和(0.17+0)。086) uSv/h在50厘米,(0。039 + 0。014)和(0。043+0.017) Sv/h (X′= 76。19日,76年。33, P < 0。05). 垂直粒子注入部位的剂量率与注入粒子的总活度、标准活度下的剂量率与注入深度呈线性关系。对同床成人、同床同事、同床未成年人和孕妇的剂量率预警时间与剂量率的关系为:t (d) = -106。616 + 83。779lnD (t), t (d) = 26。556 + 85。933lnD (t), t (d) = 3.088 + 85。结论s - I粒子植入后,周围环境辐射剂量较低,保证了辐射安全;所测剂量率随注入粒子总活性的降低和注入深度的增加而减小;同时,根据所测剂量率或植入粒子的总活度及植入粒子的深度,计算不同组的预警时间,进行个体化防护。研究1I粒子植入治疗腹盆腔肿瘤患者的环境辐射剂量率和有效剂量,为不同人群的职业防护提供参考。应用袖珍剂量仪监测42例经125I粒子植入的腹盆腔肿瘤术后24h内的放射剂量率。通过曲线拟合得到注入粒子的总活度与测量剂量率之间的关系,以及标准活度下注入深度与剂量率之间的关系。根据公式,计算了剂量率与预警时间的关系。垂直粒子植入部位30 cm、50 cm和00 cm处的剂量率为(6.92+2)。87), (4);10 + 1。62)和(1.30+0)。48) u.Sv / h。(X'= 73)。71, P < 0。05). 左右两侧的剂量率分别为(0。378 + 0。(0.384+0。30cm时,Sv/h (0.53);170 + 0。089)和(0.17+0)。086) uSv/h在50厘米,(0。039 + 0。014)和(0。043+0.017) Sv/h (X′= 76。19日,76年。33, P < 0。05). 垂直粒子注入部位的剂量率与注入粒子的总活度、标准活度下的剂量率与注入深度呈线性关系。对同床成人、同床同事、同床未成年人和孕妇的剂量率预警时间与剂量率的关系为:t (d) = -106。616 + 83。779lnD (t), t (d) = 26。556 + 85。933lnD (t), t (d) = 3.088 + 85。017InD (t). s I粒子植入后,周围环境辐射剂量低,保证辐射安全;所测剂量率随注入粒子总活性的降低和注入深度的增加而减小;同时,根据所测剂量率或植入粒子的总活度及植入粒子的深度,计算不同组的预警时间,进行个体化防护。
{"title":"PO100","authors":"Juan Wang, Hongtao Zhang, Yansong Liang, Jianmin Li","doi":"10.1016/j.brachy.2023.06.201","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.201","url":null,"abstract":"Purpose To study the radiation dose rate and effective dose in ambient environment due to 1I seed implantation in the treatment of the patients suffering abdominal and pelvic tumors, so as to provide reference for occupational protection of different groups. Materials and Methods Within 24hours after operation , the radiation dose rate to 42 patients with abdominal and pelvic tumor with 125I seed implantation was monitored by using pocket dosimeter. The relationships between the total activity in the implanted particles and the measured dose rate, as well as hetween the implanted depth and the dose rate under the standard activity, were obtained by curve fitting. According to the formula, the relationship between the dose rate and the warning time was calculated. Results The dose rates at 30 cm , 50 cm and00 cm of vertical particle implantation site were (6.92+2. 87) , (4. 10+1. 62) and (1.30+0. 48) u.Sv/h. respectively (X'= 73. 71, P<0. 05). The dose rates on the left and right sides were (0. 378+0. 156) and (0.384+0. 153) Sv/h at 30 cm, (0. 170+0. 089) and (0.17+0. 086) uSv/h at 50 cm, (0. 039 +0. 014) and (0. 043+0.017) Sv/h at 100 cm, respectively (X'= 76. 19, 76. 33, P<0. 05). There was a linear relationship between the dose rate at the vertical particle implantation site and the total activity in the implanted particles, and between the dose rate and the implantation depth under the standard activity. The relationship between the warning time and the dose rate to adults in the same bed, co-workers , minors in the same bed and pregnant women were as follows: t (d) = -106. 616+83. 779lnD (t) , t (d) = 26. 556+85. 933lnD (t), t (d) = 3.088 + 85. 017InD (t). Conclusions After's I seed implantation, the radiation dose in the ambient environment is low, ensuring the radiation safety; and the measured dose rate decreases with the decrease in the total activity in the implanted particle and the increase in the implantation depth; at the same time, the warning time for different groups is calculated according to the measured dose rate or the total activity in the implanted particle and the depth of the implanted particle, so as to carry out individualized protection. To study the radiation dose rate and effective dose in ambient environment due to 1I seed implantation in the treatment of the patients suffering abdominal and pelvic tumors, so as to provide reference for occupational protection of different groups. Within 24hours after operation , the radiation dose rate to 42 patients with abdominal and pelvic tumor with 125I seed implantation was monitored by using pocket dosimeter. The relationships between the total activity in the implanted particles and the measured dose rate, as well as hetween the implanted depth and the dose rate under the standard activity, were obtained by curve fitting. According to the formula, the relationship between the dose rate and the warning time was calculated. The dose rates at 30 cm , 50 cm and00 cm of vertical ","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":"135434370","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}
引用次数: 0
PO125 PO125
Pub Date : 2023-09-01 DOI: 10.1016/j.brachy.2023.06.225
Matthew Jalbert, John J. Munro, David C. Medich
Purpose Tungsten-181 is a middle energy radioisotope with an average energy of Eavg=64.3keV and a half-life of T1/2=140d that holds promise as a new HDR brachytherapy source. This is because, except for its two highest energy photons which have energies of 136 keV (yield: 0.0311%) and 156 keV (yield: 0.0083%), this source is dominated by photons which lie between 56 keV to 67 keV. Such photons easily are absorbed by high Z materials but scatter readily in water. This study will investigate the treatment needs and intensity modulation capabilities of W-181 and compare these results to those of Iridium-192 and Ytterbium-169. Materials and Methods Simulations were conducted using the Monte Carlo N-Particle Transport Code (MCNP6.2) to calculate the Dose Rate Constant, Radial Dose Function, photon self-absorption, and treatment activity of a 3.5mm long and 0.6mm diameter pellet encapsulated in stainless steel. We finally evaluated the intensity modulation capabilities of this pellet and compared it to Ir-192 and Yb-169. Results Our W-181 pellet had a Dose Rate Constant of 1.01 ± 0.01cGy∙h-1∙U-1 and a Radial Dose Function, which was fit to a 5th polynomial function to obtain the following coefficients: a0=9.01E-1 a1=8.60E-2 a2=2.96E-2 a3=-1.05E-2 a4=1.00E-3 a5=-3.00E-5. With respect to shielding and intensity modulation, 0.3mm of gold shielding reduced W-181’s absorbed dose by 86%, Yb-169′s dose by 62%, and Ir-192’s dose by 15%. While this isotope therefore can be an excellent candidate for IMBT, we also found that it is limited by a high photon self-absorption due to tungsten's very high density (19.3g/cm3) and atomic number (74). Specifically, we found that a W-181 pellet would provide an absorbed dose rate per unit activity of 1.84 ± 0.01cGy∙Ci-1min-1 to a treatment area 1cm from the source as opposed to Ir-192 and Yb-169’s 31.0 ± 0.37 cGy∙Ci-1∙min-1 and 8.18 ± 0.11 cGy∙Ci-1∙min-1, respectively. A W-181 therapeutic source therefore would require a higher treatment activity than a Yb-169 or Ir-192 source. Conclusions The capabilities of W-181 for intensity modulation outperforms that of Ir-192 and even Yb-169. Given these results, W-181 shows promise as a brachytherapy source, especially in multi-pellet configurations. Tungsten-181 is a middle energy radioisotope with an average energy of Eavg=64.3keV and a half-life of T1/2=140d that holds promise as a new HDR brachytherapy source. This is because, except for its two highest energy photons which have energies of 136 keV (yield: 0.0311%) and 156 keV (yield: 0.0083%), this source is dominated by photons which lie between 56 keV to 67 keV. Such photons easily are absorbed by high Z materials but scatter readily in water. This study will investigate the treatment needs and intensity modulation capabilities of W-181 and compare these results to those of Iridium-192 and Ytterbium-169. Simulations were conducted using the Monte Carlo N-Particle Transport Code (MCNP6.2) to calculate the Dose Rate Constant,
钨-181是一种平均能量为Eavg=64.3keV,半衰期为T1/2=140d的中能放射性同位素,有望成为一种新的HDR近距离放射治疗源。这是因为,除了两个能量最高的光子,分别为136 keV(产率:0.0311%)和156 keV(产率:0.0083%),这个源主要由56 keV到67 keV之间的光子组成。这种光子很容易被高Z材料吸收,但很容易在水中散射。本研究将探讨W-181的处理需求和强度调制能力,并将这些结果与铱-192和镱-169进行比较。材料与方法采用蒙特卡罗n粒子输运程序(MCNP6.2)模拟计算了长3.5mm、直径0.6mm的不锈钢微球的剂量率常数、径向剂量函数、光子自吸收和处理活度。我们最后评估了该颗粒的强度调制能力,并将其与Ir-192和Yb-169进行了比较。结果W-181颗粒的剂量率常数为1.01±0.01 gy∙h-1∙U-1,径向剂量函数拟合为5次多项式函数,可得系数:a0=9.01E-1 a1=8.60E-2 a2=2.96E-2 a3=-1.05E-2 a4=1.00E-3 a5=-3.00E-5。在屏蔽和强度调制方面,0.3mm的金屏蔽使W-181的吸收剂量降低86%,使Yb-169的吸收剂量降低62%,使Ir-192的吸收剂量降低15%。虽然这种同位素因此可以成为IMBT的优秀候选者,但我们也发现由于钨的非常高的密度(19.3g/cm3)和原子序数(74),它受到高光子自吸收的限制。具体而言,我们发现W-181微球对距离源1cm的治疗区域提供的单位活性吸收剂量率为1.84±0.01 gy∙Ci-1min-1,而Ir-192和Yb-169分别为31.0±0.37 cGy∙Ci-1∙min-1和8.18±0.11 cGy∙Ci-1∙min-1。因此,W-181治疗源需要比Yb-169或Ir-192源更高的治疗活性。结论W-181的强度调制能力优于Ir-192,甚至优于Yb-169。鉴于这些结果,W-181显示出作为近距离治疗源的希望,特别是在多颗粒配置中。钨-181是一种中等能放射性同位素,平均能量为Eavg=64.3keV,半衰期为T1/2=140d,有望成为一种新的HDR近距离放射治疗源。这是因为,除了两个能量最高的光子,分别为136 keV(产率:0.0311%)和156 keV(产率:0.0083%),这个源主要由56 keV到67 keV之间的光子组成。这种光子很容易被高Z材料吸收,但很容易在水中散射。本研究将探讨W-181的处理需求和强度调制能力,并将这些结果与铱-192和镱-169进行比较。采用蒙特卡罗n粒子输运程序(MCNP6.2)模拟了长3.5mm、直径0.6mm的不锈钢微球的剂量率常数、径向剂量函数、光子自吸收和处理活度。我们最后评估了该颗粒的强度调制能力,并将其与Ir-192和Yb-169进行了比较。我们的W-181颗粒的剂量率常数为1.01±0.01 gy∙h-1∙U-1,其径向剂量函数拟合为5次多项式函数,得到系数:a0=9.01E-1 a1=8.60E-2 a2=2.96E-2 a3=-1.05E-2 a4=1.00E-3 a5=-3.00E-5。在屏蔽和强度调制方面,0.3mm的金屏蔽使W-181的吸收剂量降低86%,使Yb-169的吸收剂量降低62%,使Ir-192的吸收剂量降低15%。虽然这种同位素因此可以成为IMBT的优秀候选者,但我们也发现由于钨的非常高的密度(19.3g/cm3)和原子序数(74),它受到高光子自吸收的限制。具体而言,我们发现W-181微球对距离源1cm的治疗区域提供的单位活性吸收剂量率为1.84±0.01 gy∙Ci-1min-1,而Ir-192和Yb-169分别为31.0±0.37 cGy∙Ci-1∙min-1和8.18±0.11 cGy∙Ci-1∙min-1。因此,W-181治疗源需要比Yb-169或Ir-192源更高的治疗活性。W-181的强度调制能力优于Ir-192甚至Yb-169。鉴于这些结果,W-181显示出作为近距离治疗源的希望,特别是在多颗粒配置中。
{"title":"PO125","authors":"Matthew Jalbert, John J. Munro, David C. Medich","doi":"10.1016/j.brachy.2023.06.225","DOIUrl":"https://doi.org/10.1016/j.brachy.2023.06.225","url":null,"abstract":"Purpose Tungsten-181 is a middle energy radioisotope with an average energy of Eavg=64.3keV and a half-life of T1/2=140d that holds promise as a new HDR brachytherapy source. This is because, except for its two highest energy photons which have energies of 136 keV (yield: 0.0311%) and 156 keV (yield: 0.0083%), this source is dominated by photons which lie between 56 keV to 67 keV. Such photons easily are absorbed by high Z materials but scatter readily in water. This study will investigate the treatment needs and intensity modulation capabilities of W-181 and compare these results to those of Iridium-192 and Ytterbium-169. Materials and Methods Simulations were conducted using the Monte Carlo N-Particle Transport Code (MCNP6.2) to calculate the Dose Rate Constant, Radial Dose Function, photon self-absorption, and treatment activity of a 3.5mm long and 0.6mm diameter pellet encapsulated in stainless steel. We finally evaluated the intensity modulation capabilities of this pellet and compared it to Ir-192 and Yb-169. Results Our W-181 pellet had a Dose Rate Constant of 1.01 ± 0.01cGy∙h-1∙U-1 and a Radial Dose Function, which was fit to a 5th polynomial function to obtain the following coefficients: a0=9.01E-1 a1=8.60E-2 a2=2.96E-2 a3=-1.05E-2 a4=1.00E-3 a5=-3.00E-5. With respect to shielding and intensity modulation, 0.3mm of gold shielding reduced W-181’s absorbed dose by 86%, Yb-169′s dose by 62%, and Ir-192’s dose by 15%. While this isotope therefore can be an excellent candidate for IMBT, we also found that it is limited by a high photon self-absorption due to tungsten's very high density (19.3g/cm3) and atomic number (74). Specifically, we found that a W-181 pellet would provide an absorbed dose rate per unit activity of 1.84 ± 0.01cGy∙Ci-1min-1 to a treatment area 1cm from the source as opposed to Ir-192 and Yb-169’s 31.0 ± 0.37 cGy∙Ci-1∙min-1 and 8.18 ± 0.11 cGy∙Ci-1∙min-1, respectively. A W-181 therapeutic source therefore would require a higher treatment activity than a Yb-169 or Ir-192 source. Conclusions The capabilities of W-181 for intensity modulation outperforms that of Ir-192 and even Yb-169. Given these results, W-181 shows promise as a brachytherapy source, especially in multi-pellet configurations. Tungsten-181 is a middle energy radioisotope with an average energy of Eavg=64.3keV and a half-life of T1/2=140d that holds promise as a new HDR brachytherapy source. This is because, except for its two highest energy photons which have energies of 136 keV (yield: 0.0311%) and 156 keV (yield: 0.0083%), this source is dominated by photons which lie between 56 keV to 67 keV. Such photons easily are absorbed by high Z materials but scatter readily in water. This study will investigate the treatment needs and intensity modulation capabilities of W-181 and compare these results to those of Iridium-192 and Ytterbium-169. Simulations were conducted using the Monte Carlo N-Particle Transport Code (MCNP6.2) to calculate the Dose Rate Constant, ","PeriodicalId":93914,"journal":{"name":"Brachytherapy","volume":"41 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":"135434408","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}
引用次数: 0
PO17 PO17
Pub Date : 2023-09-01 DOI: 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
目的探讨125I粒子植入术治疗复发性宫颈鳞状细胞癌后剂量参数与肿瘤体积缩小率的关系,以获得更好的预测疗效的参数。方法对26例宫颈鳞状细胞癌30处病变的临床资料进行回顾性分析。所有患者术后立即进行剂量验证,获得术后D90(90%靶体积可接受的最小外周剂量)。对患者进行定期随访。根据实际随访时的CT图像,计算t月末肿瘤体积缩小比(Rt)、术后1月肿瘤体积缩小比(R1)、第1个月实际吸收剂量(D1m)、第1个月疗效校正吸收剂量(D1e)、第1个月敏感性校正吸收剂量(D1s)和第t个月实际吸收剂量(Dt)。对术后D90、R1进行曲线拟合,对术后D90、D1m、D1e、D1s、Rt进行曲线拟合,找出各参数与肿瘤体积缩小比的相关性。结果的平均值D90,直到D1m D1e, d1, Rt, R1were(105.4±22.8)Gy, Gy(30.9±7.4),(37.1±8.9)Gy, Gy(37.8±11.6),(39.4±17)%,%(20.4±12)。术后D90与R1呈正相关,术后D90、D1m、D1e、D1s与rt呈正相关。方程为: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)。结论术后ved90、D1m、D1e、D1s与术后肿瘤体积缩小比呈正相关,可用于预测原发性复发宫颈鳞状细胞癌颗粒植入患者的疗效。与D90、D1m和D1e相比,D1s具有更好的预测效果。探讨125I粒子植入治疗复发性宫颈鳞状细胞癌后剂量参数与肿瘤体积缩小率的关系,以获得较好的预测疗效的参数。对26例宫颈鳞状细胞癌患者30处病变进行回顾性分析。所有患者术后立即进行剂量验证,获得术后D90(90%靶体积可接受的最小外周剂量)。对患者进行定期随访。根据实际随访时的CT图像,计算t月末肿瘤体积缩小比(Rt)、术后1月肿瘤体积缩小比(R1)、第1个月实际吸收剂量(D1m)、第1个月疗效校正吸收剂量(D1e)、第1个月敏感性校正吸收剂量(D1s)和第t个月实际吸收剂量(Dt)。对术后D90、R1进行曲线拟合,对术后D90、D1m、D1e、D1s、Rt进行曲线拟合,找出各参数与肿瘤体积缩小比的相关性。D90的平均值,直到D1m D1e, d1, Rt, R1were(105.4±22.8)Gy, Gy(30.9±7.4),(37.1±8.9)Gy, Gy(37.8±11.6),(39.4±17)%,%(20.4±12)。术后D90与R1呈正相关,术后D90、D1m、D1e、D1s与rt呈正相关。方程为: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)。术后ved90、D1m、D1e、D1s与术后肿瘤体积缩小比呈正相关,可用于预测原发性复发宫颈鳞状细胞癌颗粒植入患者的疗效。与D90、D1m和D1e相比,D1s具有更好的预测效果。
{"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}
引用次数: 0
PO57 PO57
Pub Date : 2023-09-01 DOI: 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
在过去的几年中,高剂量率(HDR)近距离放射治疗方案生成的关键改进来自于多准则优化(MCO)算法的发展,该算法可以在几秒钟内生成数千个帕累托最优方案。这带来了一个转变,目标从生成一个可接受的计划转变为从数千个计划中选择最佳计划。所选择的计划不仅取决于计划者,而且还需要大约5-10分钟来选择首选计划。目前工作的目的是加快这一进程,并为不同的专家找到关于计划质量的共同基础。材料与方法基于ResNet深度神经网络架构,开发了一种人工智能算法,从生成的方案中选择最佳方案。该算法根据三维剂量分布和解剖结构将方案分为三类,(1)违反硬标准(最低),(2)尊重硬标准,(3)尊重软标准,每一类都比前一类严格(提高方案质量)。这三个等级是根据我们机构在单个分数中使用的剂量学标准为15 Gy。对于分类,模型越确信某计划属于第3类,则该计划越好。为了模仿专家的行为,对膀胱、直肠和尿道实施了类似视觉的标准。视觉标准定义为与危险器官的等剂量距离为100%和125%。在训练过程中,算法学习输入(3D剂量和解剖结构)和输出(视觉和DVH标准)之间的联系。850名先前接受过治疗的前列腺癌患者被用于培训,另外20名患者被两名专家(临床医学物理学家)作为观察者间MCO研究的一部分进行评估,用于验证。对于培训,使用MCO为每个患者生成100个计划,随机选择27000个计划,使每个班级的数量相同。NVIDIA GeForce RTX 3090用于训练。结果该模型对2000个方案按偏好排序需要20秒(专家对4个方案排序需要5-10分钟)。目前培训时间没有优化,27000计划75个epoch的培训时间不到2天。20例验证患者中,1、2、3类患者分别占39.9±20.2%、46.4±15.3%、14.5±21.9%。表1显示了20个案例的结果,每个案例有2000个计划;根据模型和专家选择的方案计算平均值和偏差。表格中包含了第3类排名最好和最差的计划。根据模型查看最佳方案,并将其与两位专家选择的方案进行比较,结果表明行为是相似的。在两位专家选择的40个方案中,我们的模型有3次将同一方案列为最佳方案。更深入地看,我们发现专家1和专家2选择的方案在2000个方案中排名中位数分别为71.5和136.5。在其中一种情况下,没有符合第3类DVH标准的计划,结果是次优的;每位专家选择的方案不符合其中1个标准,而我们的模型选择的方案不符合3个标准。这种类型的行为是不受欢迎的,接下来的步骤之一是解决这个罕见的问题,在这个问题上,达到所有标准是不可行的。加入视觉标准后,第3类的设计数量从原先的16500个减少到9000个。结论该方法快速,缩短了MCO计划的时间,初步结果显示了临床应用的潜力。该方法是灵活的,可以根据需要调整所有标准。未来的工作将研究模型改进,专家给出的最佳3类方案的非劣效性,以及如何快速限制导航方案的数量以获得更快的规划时间。在过去几年中,高剂量率(HDR)近距离放射治疗方案生成的关键改进来自多准则优化(MCO)算法的发展,该算法可在几秒钟内生成数千个帕累托最优方案。这带来了一个转变,目标从生成一个可接受的计划转变为从数千个计划中选择最佳计划。所选择的计划不仅取决于计划者,而且还需要大约5-10分钟来选择首选计划。目前工作的目的是加快这一进程,并为不同的专家找到关于计划质量的共同基础。开发了一种基于ResNet深度神经网络架构的人工智能算法,从生成的方案中选择最佳方案。 该算法根据三维剂量分布和解剖结构将方案分为三类,(1)违反硬标准(最低),(2)尊重硬标准,(3)尊重软标准,每一类都比前一类严格(提高方案质量)。这三个等级是根据我们机构在单个分数中使用的剂量学标准为15 Gy。对于分类,模型越确信某计划属于第3类,则该计划越好。为了模仿专家的行为,对膀胱、直肠和尿道实施了类似视觉的标准。视觉标准定义为与危险器官的等剂量距离为100%和125%。在训练过程中,算法学习输入(3D剂量和解剖结构)和输出(视觉和DVH标准)之间的联系。850名先前接受过治疗的前列腺癌患者被用于培训,另外20名患者被两名专家(临床医学物理学家)作为观察者间MCO研究的一部分进行评估,用于验证。对于培训,使用MCO为每个患者生成100个计划,随机选择27000个计划,使每个班级的数量相同。NVIDIA GeForce RTX 3090用于训练。该模型按偏好顺序对2000个计划进行分类需要20秒(专家对4个首选计划进行排序需要5-10分钟)。目前培训时间没有优化,27000计划75个epoch的培训时间不到2天。20例验证患者中,1、2、3类患者分别占39.9±20.2%、46.4±15.3%、14.5±21.9%。表1显示了20个案例的结果,每个案例有2000个计划;根据模型和专家选择的方案计算平均值和偏差。表格中包含了第3类排名最好和最差的计划。根据模型查看最佳方案,并将其与两位专家选择的方案进行比较,结果表明行为是相似的。在两位专家选择的40个方案中,我们的模型有3次将同一方案列为最佳方案。更深入地看,我们发现专家1和专家2选择的方案在2000个方案中排名中位数分别为71.5和136.5。在其中一种情况下,没有符合第3类DVH标准的计划,结果是次优的;每位专家选择的方案不符合其中1个标准,而我们的模型选择的方案不符合3个标准。这种类型的行为是不受欢迎的,接下来的步骤之一是解决这个罕见的问题,在这个问题上,达到所有标准是不可行的。加入视觉标准后,第3类的设计数量从原先的16500个减少到9000个。该方法快速,为MCO计划增加了可忽略不计的时间,初步结果显示了临床应用的潜力。该方法是灵活的,可以根据需要调整所有标准。未来的工作将研究模型改进,专家给出的最佳3类方案的非劣效性,以及如何快速限制导航方案的数量以获得更快的规划时间。 该算法根据三维剂量分布和解剖结构将方案分为三类,(1)违反硬标准(最低),(2)尊重硬标准,(3)尊重软标准,每一类都比前一类严格(提高方案质量)。这三个等级是根据我们机构在单个分数中使用的剂量学标准为15 Gy。对于分类,模型越确信某计划属于第3类,则该计划越好。为了模仿专家的行为,对膀胱、直肠和尿道实施了类似视觉的标准。视觉标准定义为与危险器官的等剂量距离为100%和125%。在训练过程中,算法学习输入(3D剂量和解剖结构)和输出(视觉和DVH标准)之间的联系。850名先前接受过治疗的前列腺癌患者被用于培训,另外20名患者被两名专家(临床医学物理学家)作为观察者间MCO研究的一部分进行评估,用于验证。对于培训,使用MCO为每个患者生成100个计划,随机选择27000个计划,使每个班级的数量相同。NVIDIA GeForce RTX 3090用于训练。该模型按偏好顺序对2000个计划进行分类需要20秒(专家对4个首选计划进行排序需要5-10分钟)。目前培训时间没有优化,27000计划75个epoch的培训时间不到2天。20例验证患者中,1、2、3类患者分别占39.9±20.2%、46.4±15.3%、14.5±21.9%。表1显示了20个案例的结果,每个案例有2000个计划;根据模型和专家选择的方案计算平均值和偏差。表格中包含了第3
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引用次数: 0
PO115 PO115
Pub Date : 2023-09-01 DOI: 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
目的围手术期多导管间质近距离加速乳房部分照射是术后的一种替代选择,它在特异性和舒适性方面为患者提供了优势,因为它避免了第二次手术。由于模拟CT扫描是在干预后48小时进行的,因此偶尔可以观察到立即的组织变化,如气隙。据我们所知,在这方面没有文献发表,因此本研究的目的是评估在多导管乳腺癌围手术期近距离放疗计划和治疗时显著气隙的影响。方法与材料连续2例气隙大于6cc的病例。对于每个病例,在手术(肿瘤切除+导管插入)后48小时进行计划CT扫描。治疗计划按照科室方案执行,采用超分馏方案:每12小时进行3次745 cGy的分馏。第二次CT扫描是在最后一次治疗后,导管取出之前进行的。在治疗前和治疗后的ct中对气隙进行了轮廓,并对其体积进行了比较。扫描结果已经融合并评估了剂量学差异。两次扫描共分析了13根导管。结果观察到治疗后的气隙体积缩小(-10%和-30%)。CT扫描融合比较13根导管,其中12根导管在CTV内位置移位≤1.5 mm(中位移位1mm), 1根导管在治疗后CT上移位2.7 mm。治疗前后扫描CTVD90和V100的平均变化分别为-1.5和-1.7%。周围器官的剂量变化为:皮肤Dmax为-10和-3%,肋骨Dmax为+15和+15%,同侧肺Dmax为+12和+13%。剂量学差异在任何情况下都没有超过容忍和覆盖限度。结论通过对两例病例的分析,气隙的体积缩小似乎不影响种植体的几何形状,大多数导管在初始位置保持稳定。覆盖参数和桨叶剂量的离散变化满足预先建立的约束条件。这些结果的确认以及这些变化的临床相关性必须在未来的研究中进行检查,包括更多的患者。多导管间质近距离加速乳房围手术期局部照射是术后的一种替代选择,它在特异性和舒适性方面为患者提供了优势,因为它避免了第二次手术。由于模拟CT扫描是在干预后48小时进行的,因此偶尔可以观察到立即的组织变化,如气隙。据我们所知,在这方面没有文献发表,因此本研究的目的是评估在多导管乳腺癌围手术期近距离放疗计划和治疗时显著气隙的影响。连续两例气隙> 6cc。对于每个病例,在手术(肿瘤切除+导管插入)后48小时进行计划CT扫描。治疗计划按照科室方案执行,采用超分馏方案:每12小时进行3次745 cGy的分馏。第二次CT扫描是在最后一次治疗后,导管取出之前进行的。在治疗前和治疗后的ct中对气隙进行了轮廓,并对其体积进行了比较。扫描结果已经融合并评估了剂量学差异。两次扫描共分析了13根导管。在治疗后的气隙中观察到体积减少(每种病例-10%和-30%)。CT扫描融合比较13根导管,其中12根导管在CTV内位置移位≤1.5 mm(中位移位1mm), 1根导管在治疗后CT上移位2.7 mm。治疗前后扫描CTVD90和V100的平均变化分别为-1.5和-1.7%。周围器官的剂量变化为:皮肤Dmax为-10和-3%,肋骨Dmax为+15和+15%,同侧肺Dmax为+12和+13%。剂量学差异在任何情况下都没有超过容忍和覆盖限度。通过对两个病例的分析,气隙的体积减小似乎并不影响植入物的几何形状,大多数导管在其初始位置保持稳定。覆盖参数和桨叶剂量的离散变化满足预先建立的约束条件。这些结果的确认以及这些变化的临床相关性必须在未来的研究中进行检查,包括更多的患者。
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引用次数: 0
PO50 PO50
Pub Date : 2023-09-01 DOI: 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
目的:根据对3例典型病例的剂量学分析(1),与单次或双次近距离放射治疗相比,三次串联近距离放射治疗(TTB)提供了更好的子宫覆盖范围,并将OARs的剂量降至最低。我们报告了TTB在一组医学上不能手术的子宫内膜癌(EC)患者中的技术可行性和剂量学。材料和方法:对2014-2021年间在同一医院接受TTB±外束放疗(EBRT)的所有医学上不能手术的EC患者(n=30)进行了IRB批准的回顾性研究。患者均行离线MRI融合规划(n= 24,80 %),术中均行经腹超声进行扩张和装置放置。FIGO分期为1a-4b期;≥2期患者接受TTB +/-卵泡治疗。Kaplan-Meier估计用于估计局部无故障生存(LFFS)。根据ABS指南,膀胱、直肠和肠道剂量至2cc (D2cc)的2 gy当量剂量(EQD2)限制分别为<90Gy、<75Gy和<65Gy。计算每个患者GTV和CTV以及危险器官(OAR)的EQD2累积D90%(最小剂量至体积的90%)。报告的统计数据是中值和范围。收集每个串联的停留时间贡献。结果30例患者中,93.3%的患者接受了EBRT和TTB治疗。确诊时平均年龄65.3岁(范围40.5-88.7岁)。BMI中位数为48.1(范围:27.8-69)。EBRT的中位处方剂量为45 Gy(范围:21-50.4 Gy),近距离治疗的5次处方剂量为22.25 Gy(范围:16.5-49.1 Gy)。累积EQD2对GTV的中位数为78.6 Gy(范围:67.8 ~ 86.6),对CTV的中位数为67.6 Gy(范围:48 ~ 79.8),其中TTB对GTV和CTV的EQD2中位数分别为33.8 Gy和23.3 Gy。4例(13.3%)患者由于担心后宫颈和/或子宫后壁穿孔而未放置中央串联。在整个队列中,在77% (n=23)和60% (n=18)的患者中,中心串联分别贡献了至少10%和15%的停留时间(图1)。在三分之一的患者中,中心串联贡献了≥30%的停留时间。横向串联占总住宅的大部分(82%,范围:32-100%)。中位随访时间为32.1个月(1.7 ~ 93.6个月)。kaplan - meier估计的1年/5年LFFS为96.2%/84.1%。累积D2cc:膀胱71.0Gy(范围:25.2-91.2Gy),直肠53.6Gy(范围:25.2-76.2Gy),小肠58.1Gy(范围:14.1-72Gy)。术中、术后未发生手术相关穿孔、出血或急性并发症。结论TTB + EBRT治疗不能手术的EC患者是安全的,大多数病例达到了可接受的目标覆盖率。虽然根据我们的经验,后路/中央串联插入可能并不适用于所有患者,但这一限制并不妨碍适当的剂量分配和局部控制。进一步的分析可能有助于预先确定导致插入困难的解剖学因素和实现适当剂量测定的替代方法。(1)近距离放疗。2014年5月- 6月;13(3):268-74根据对3例代表性病例的剂量学分析,三次串联近距离放疗(TTB)与单次或双次串联治疗相比,提供了更好的子宫覆盖范围,并将OARs的剂量降至最低(1)。我们报告了TTB在医学上不能手术的子宫内膜癌(EC)患者队列中的技术可行性和剂量学。一项经IRB批准的回顾性研究对2014-2021年间在单一机构(n=30)接受TTB±外束放疗(EBRT)治疗的所有医学上不能手术的EC患者进行了研究。患者均行离线MRI融合规划(n= 24,80 %),术中均行经腹超声进行扩张和装置放置。FIGO分期为1a-4b期;≥2期患者接受TTB +/-卵泡治疗。Kaplan-Meier估计用于估计局部无故障生存(LFFS)。根据ABS指南,膀胱、直肠和肠道剂量至2cc (D2cc)的2 gy当量剂量(EQD2)限制分别为<90Gy、<75Gy和<65Gy。计算每个患者GTV和CTV以及危险器官(OAR)的EQD2累积D90%(最小剂量至体积的90%)。报告的统计数据是中值和范围。收集每个串联的停留时间贡献。在30例患者中,93.3%的患者接受了EBRT和TTB。确诊时平均年龄65.3岁(范围40.5-88.7岁)。BMI中位数为48.1(范围:27.8-69)。EBRT的中位处方剂量为45 Gy(范围:21-50.4 Gy),近距离治疗的5次处方剂量为22.25 Gy(范围:16.5-49.1 Gy)。累积EQD2对GTV的中位数为78.6 Gy(范围:67.8- 86.6),对CTV的中位数为67.6 Gy(范围:48- 79.8),其中TTB对EQD2的中位数贡献为33.8 Gy和23。 目的:根据对3例典型病例的剂量学分析(1),与单次或双次近距离放射治疗相比,三次串联近距离放射治疗(TTB)提供了更好的子宫覆盖范围,并将OARs的剂量降至最低。我们报告了TTB在一组医学上不能手术的子宫内膜癌(EC)患者中的技术可行性和剂量学。材料和方法:对2014-2021年间在同一医院接受TTB±外束放疗(EBRT)的所有医学上不能手术的EC患者(n=30)进行了IRB批准的回顾性研究。患者均行离线MRI融合规划(n= 24,80 %),术中均行经腹超声进行扩张和装置放置。FIGO分期为1a-4b期;≥2期患者接受TTB +/-卵泡治疗。Kaplan-Meier估计用于估计局部无故障生存(LFFS)。根据ABS指南,膀胱、直肠和肠道剂量至2cc (D2cc)的2 gy当量剂量(EQD2)限制分别为<90Gy、<75Gy和<65Gy。计算每个患者GTV和CTV以及危险器官(OAR)的EQD2累积D90%(最小剂量至体积的90%)。报告的统计数据是中值和范围。收集每个串联的停留时间贡献。结果30例患者中,93.3%的患者接受了EBRT和TTB治疗。确诊时平均年龄65.3岁(范围40.5-88.7岁)。BMI中位数为48.1(范围:27.8-69)。EBRT的中位处方剂量为45 Gy(范围:21-50.4 Gy),近距离治疗的5次处方剂量为22.25 Gy(范围:16.5-49.1 Gy)。累积EQD2对GTV的中位数为78.6 Gy(范围:67.8 ~ 86.6),对CTV的中位数为67.6 Gy(范围:48 ~ 79.8),其中TTB对GTV和CTV的EQD2中位数分别为33.8 Gy和23.3 Gy。4例(13.3%)患者由于担心后宫颈和/或子宫后壁穿孔而未放置中央串联。在整个队列中,在77% (n=23)和60% (n=18)的患者中,中心串联分别贡献了至少10%和15%的停留时间(图1)。在三分之一的患者中,中心串联贡献了≥30%的停留时间。横向串联占总住宅的大部分(82%,范围:32-100%)。中位随访时间为32.1个月(1.7 ~ 93.6个月)。kaplan - meier估计的1年/5年LFFS为96.2%/84.1%。累积D2cc:膀胱71.0Gy(范围:25.2-91.2Gy),直肠53.6Gy(范围:25.2-76.2Gy),小肠58.1Gy(范围:14.1-72Gy)。术中、术后未发生手术相关穿孔、出血或急性并发症。结论TTB + EBRT治疗不能手术的EC患者是安全
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Brachytherapy
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