Evaluation and prediction of pelvic dose in postoperative IMRT for cervical cancer

中华放射肿瘤学杂志 Pub Date : 2020-02-15 DOI:10.3760/CMA.J.ISSN.1004-4221.2020.02.013

Yanze Sun, Yongqiang Yang, J. Qian

{"title":"Evaluation and prediction of pelvic dose in postoperative IMRT for cervical cancer","authors":"Yanze Sun, Yongqiang Yang, J. Qian","doi":"10.3760/CMA.J.ISSN.1004-4221.2020.02.013","DOIUrl":null,"url":null,"abstract":"Objective \nTo evaluate and predict the pelvic dose by analyzing two pelvic contour definitions and identify the influencing factors of the pelvic dose in postoperative IMRT for cervical cancer, aiming to provide reference for postoperative pelvis-sparing IMRT for cervical cancer. \n \n \nMethods \nSixty cervical cancer patients receiving postoperative IMRT with unrestricted pelvic dose were selected. Two sets of pelvic contours (pelvic anatomy and pelvic Mell) were delineated as per the anatomical and Mell methods. The dose relationship between two methods was analyzed after redesigning the treatment plan by limiting dose of pelvic anatomy. The correlation analysis was performed by Pearson’s correlation method. The factors affecting the pelvic anatomy dose were identified by Logistic multivariate regression analysis and a dose prediction model was subsequently established. \n \n \nResults \nThe volumes of pelvic anatomy and pelvic Mell were 925.82 cm3 and 1141.20 cm3(P=0.000). There was a significant correlation between them (r>0.622, P=0.000). The dose of pelvic anatomy was significantly higher than that of pelvic Mell. The relationship of V10, V20 and V30 between them was y=-8+ 1.01x, y=-13+ 1.05x and y=-4+ 0.9x, respectively. The dose limits of pelvic Mell recommended by literatures(V10<90%, V20<75%, V30<60%) were translated into V10<97%, V20<83% and V30<70%, respectively. The pelvic anatomy dose was significantly reduced after dose limiting. The V10, V20, V30 and Dmean were significantly decreased by 3.64%, 12.69%, 12.02% and 6.93%(P=0.000, 0.000, 0.000), respectively. Multivariate analysis showed that the overlapping volume of pelvic anatomy within PTV was an independent influencing factor of pelvic anatomy dose (P<0.05). Patients with a relative overlapping volume of less than 18% could easily meet the dose limiting requirement. \n \n \nConclusions \nBoth two pelvic contour definitions can be applied in postoperative pelvis-sparing IMRT for cervical cancer. Use of pelvic dose limiting can significantly reduce the IMRT dose. The overlapping volume of the pelvis within PTV is an independent influencing factor of pelvic dose. Patients whose overlapping volume within the PTV relative to pelvis is less than 18% can easily meet the dose limiting requirement. \n \n \nKey words: \nCervical cancer/intensity-modulated radiotherapy; Pelvis; Dosimetry","PeriodicalId":10288,"journal":{"name":"中华放射肿瘤学杂志","volume":"29 1","pages":"136-140"},"PeriodicalIF":0.0000,"publicationDate":"2020-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"中华放射肿瘤学杂志","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.3760/CMA.J.ISSN.1004-4221.2020.02.013","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}

引用次数: 1

Abstract

Objective To evaluate and predict the pelvic dose by analyzing two pelvic contour definitions and identify the influencing factors of the pelvic dose in postoperative IMRT for cervical cancer, aiming to provide reference for postoperative pelvis-sparing IMRT for cervical cancer. Methods Sixty cervical cancer patients receiving postoperative IMRT with unrestricted pelvic dose were selected. Two sets of pelvic contours (pelvic anatomy and pelvic Mell) were delineated as per the anatomical and Mell methods. The dose relationship between two methods was analyzed after redesigning the treatment plan by limiting dose of pelvic anatomy. The correlation analysis was performed by Pearson’s correlation method. The factors affecting the pelvic anatomy dose were identified by Logistic multivariate regression analysis and a dose prediction model was subsequently established. Results The volumes of pelvic anatomy and pelvic Mell were 925.82 cm3 and 1141.20 cm3(P=0.000). There was a significant correlation between them (r>0.622, P=0.000). The dose of pelvic anatomy was significantly higher than that of pelvic Mell. The relationship of V10, V20 and V30 between them was y=-8+ 1.01x, y=-13+ 1.05x and y=-4+ 0.9x, respectively. The dose limits of pelvic Mell recommended by literatures(V10<90%, V20<75%, V30<60%) were translated into V10<97%, V20<83% and V30<70%, respectively. The pelvic anatomy dose was significantly reduced after dose limiting. The V10, V20, V30 and Dmean were significantly decreased by 3.64%, 12.69%, 12.02% and 6.93%(P=0.000, 0.000, 0.000), respectively. Multivariate analysis showed that the overlapping volume of pelvic anatomy within PTV was an independent influencing factor of pelvic anatomy dose (P<0.05). Patients with a relative overlapping volume of less than 18% could easily meet the dose limiting requirement. Conclusions Both two pelvic contour definitions can be applied in postoperative pelvis-sparing IMRT for cervical cancer. Use of pelvic dose limiting can significantly reduce the IMRT dose. The overlapping volume of the pelvis within PTV is an independent influencing factor of pelvic dose. Patients whose overlapping volume within the PTV relative to pelvis is less than 18% can easily meet the dose limiting requirement. Key words: Cervical cancer/intensity-modulated radiotherapy; Pelvis; Dosimetry

查看原文本刊更多论文

宫颈癌症术后IMRT中盆腔剂量的评价与预测

目的通过分析两种骨盆轮廓定义，评价和预测癌症术后IMRT中骨盆剂量的影响因素，为癌症术后盆腔切开IMRT提供参考。方法选择60例癌症患者术后接受不限制骨盆剂量IMRT。根据解剖和Mell方法绘制了两组骨盆轮廓（骨盆解剖和骨盆Mell）。在通过限制骨盆解剖的剂量重新设计治疗方案后，分析了两种方法之间的剂量关系。相关分析采用Pearson相关法。通过Logistic多元回归分析确定了影响骨盆解剖剂量的因素，并随后建立了剂量预测模型。结果骨盆解剖体积和骨盆Mell体积分别为925.82 cm3和1141.20 cm3（P=0.000），二者之间存在显著相关性（r＞0.622，P=0.000）。V10、V20和V30之间的关系分别为y=-8+1.01x、y=-13+1.05x和y=-4+0.9x。文献推荐的盆腔Mell剂量限值（V10<90%，V20<75%，V30<60%）分别转化为V10<97%，V20<13%和V30<70%。剂量限制后，骨盆解剖部位的剂量显著减少。V10、V20、V30和Dmean分别显著下降3.64%、12.69%、12.02%和6.93%（P=0.000、0.000、0.000）。多因素分析表明，PTV内骨盆解剖结构的重叠体积是骨盆解剖结构剂量的独立影响因素（P<0.05），相对重叠体积小于18%的患者可以很容易地满足剂量限制要求。结论两种骨盆轮廓定义均可应用于癌症术后盆腔切开IMRT。使用骨盆剂量限制可以显著降低IMRT剂量。PTV内骨盆的重叠体积是骨盆剂量的独立影响因素。PTV内相对于骨盆的重叠体积小于18%的患者可以很容易地满足剂量限制要求。关键词：宫颈癌症/调强放疗；骨盆；剂量测定法

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

中华放射肿瘤学杂志

自引率

0.00%

发文量

6375

期刊介绍： The Chinese Journal of Radiation Oncology is a national academic journal sponsored by the Chinese Medical Association. It was founded in 1992 and the title was written by Chen Minzhang, the former Minister of Health. Its predecessor was the Chinese Journal of Radiation Oncology, which was founded in 1987. The journal is an authoritative journal in the field of radiation oncology in my country. It focuses on clinical tumor radiotherapy, tumor radiation physics, tumor radiation biology, and thermal therapy. Its main readers are middle and senior clinical doctors and scientific researchers. It is now a monthly journal with a large 16-page format and 80 pages of text. For many years, it has adhered to the principle of combining theory with practice and combining improvement with popularization. It now has columns such as monographs, head and neck tumors (monographs), chest tumors (monographs), abdominal tumors (monographs), physics, technology, biology (monographs), reviews, and investigations and research.