{"title":"当使用基于知识的前列腺癌计划系统时,由于器官轮廓的观察者间变异性的剂量学效应","authors":"Han Liu, Christopher Amaloo, B. Sintay, D. Wiant","doi":"10.4236/IJMPCERO.2021.102005","DOIUrl":null,"url":null,"abstract":"Purpose: Radiotherapy is a widely accepted standard of care for early-stage prostate \ncancer, and it is believed that the plan quality and treatment outcome are \nassociated with contour accuracy of both the target and organs-at-risk (OAR). \nThe purposes of this study are to 1) assess geometric and dosimetric \nuncertainties due to inter-observer contour variabilities and 2) evaluate the \neffectiveness of geometric indicators to predict target dosimetry in prostate \nradiotherapy. Methods: Twenty prostate patients were selected for this \nretrospective study. Five experienced clinicians created unique structure sets \ncontaining prostate, seminal vesicles, bladder, and rectum for each patient. A \nfully automated script and knowledge-based planning routine were utilized to \ncreate standardized and unbiased plans that could be used to evaluate changes \nin isodose distributions due to inter-observer variability in structure \nsegmentation. Plans were created on a “gold-standard” structure set, as well as \non each of the user-defined structure sets. Results: Inter-observer \nvariability of contours during structure segmentation was very low for clearly \ndefined organs such as the bladder but increased for organs without \nwell-defined borders (prostate, seminal vesicles, and rectum). For plans \ngenerated with the user-defined structure sets, strong/moderate correlations \nwere observed between the geometric indicators for target structure agreement \nand target coverage for both low-risk and intermediate-risk patient groups, \nwhile OAR indicators showed no correlation to final dosimetry. Conclusions: Target delineation is crucial in order to maintain adequate dosimetric coverage \nregardless of the associated inter-observer uncertainties in OAR contours that \nhad a limited impact upon final dosimetry.","PeriodicalId":14028,"journal":{"name":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2021-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":"{\"title\":\"Dosimetric Effects Due to Inter-Observer Variability of Organ Contouring When Utilizing a Knowledge-Based Planning System for Prostate Cancer\",\"authors\":\"Han Liu, Christopher Amaloo, B. Sintay, D. Wiant\",\"doi\":\"10.4236/IJMPCERO.2021.102005\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Purpose: Radiotherapy is a widely accepted standard of care for early-stage prostate \\ncancer, and it is believed that the plan quality and treatment outcome are \\nassociated with contour accuracy of both the target and organs-at-risk (OAR). \\nThe purposes of this study are to 1) assess geometric and dosimetric \\nuncertainties due to inter-observer contour variabilities and 2) evaluate the \\neffectiveness of geometric indicators to predict target dosimetry in prostate \\nradiotherapy. Methods: Twenty prostate patients were selected for this \\nretrospective study. Five experienced clinicians created unique structure sets \\ncontaining prostate, seminal vesicles, bladder, and rectum for each patient. A \\nfully automated script and knowledge-based planning routine were utilized to \\ncreate standardized and unbiased plans that could be used to evaluate changes \\nin isodose distributions due to inter-observer variability in structure \\nsegmentation. Plans were created on a “gold-standard” structure set, as well as \\non each of the user-defined structure sets. Results: Inter-observer \\nvariability of contours during structure segmentation was very low for clearly \\ndefined organs such as the bladder but increased for organs without \\nwell-defined borders (prostate, seminal vesicles, and rectum). For plans \\ngenerated with the user-defined structure sets, strong/moderate correlations \\nwere observed between the geometric indicators for target structure agreement \\nand target coverage for both low-risk and intermediate-risk patient groups, \\nwhile OAR indicators showed no correlation to final dosimetry. Conclusions: Target delineation is crucial in order to maintain adequate dosimetric coverage \\nregardless of the associated inter-observer uncertainties in OAR contours that \\nhad a limited impact upon final dosimetry.\",\"PeriodicalId\":14028,\"journal\":{\"name\":\"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2021-05-18\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"2\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.4236/IJMPCERO.2021.102005\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.4236/IJMPCERO.2021.102005","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Dosimetric Effects Due to Inter-Observer Variability of Organ Contouring When Utilizing a Knowledge-Based Planning System for Prostate Cancer
Purpose: Radiotherapy is a widely accepted standard of care for early-stage prostate
cancer, and it is believed that the plan quality and treatment outcome are
associated with contour accuracy of both the target and organs-at-risk (OAR).
The purposes of this study are to 1) assess geometric and dosimetric
uncertainties due to inter-observer contour variabilities and 2) evaluate the
effectiveness of geometric indicators to predict target dosimetry in prostate
radiotherapy. Methods: Twenty prostate patients were selected for this
retrospective study. Five experienced clinicians created unique structure sets
containing prostate, seminal vesicles, bladder, and rectum for each patient. A
fully automated script and knowledge-based planning routine were utilized to
create standardized and unbiased plans that could be used to evaluate changes
in isodose distributions due to inter-observer variability in structure
segmentation. Plans were created on a “gold-standard” structure set, as well as
on each of the user-defined structure sets. Results: Inter-observer
variability of contours during structure segmentation was very low for clearly
defined organs such as the bladder but increased for organs without
well-defined borders (prostate, seminal vesicles, and rectum). For plans
generated with the user-defined structure sets, strong/moderate correlations
were observed between the geometric indicators for target structure agreement
and target coverage for both low-risk and intermediate-risk patient groups,
while OAR indicators showed no correlation to final dosimetry. Conclusions: Target delineation is crucial in order to maintain adequate dosimetric coverage
regardless of the associated inter-observer uncertainties in OAR contours that
had a limited impact upon final dosimetry.