Chi-Chuan Chiou MD , Yu-Ming Liu PhD , Keng-Li Lan PhD , Yuan-Hung Wu PhD , Tzu-Yu Lai PhD , Yu-Mei Kang MD , Jui-Pin Chen MSc , Yu-Wen Hu PhD
{"title":"前列腺癌每日两个相对场与每日一个交替场碳离子放射治疗生物有效剂量的估计差异","authors":"Chi-Chuan Chiou MD , Yu-Ming Liu PhD , Keng-Li Lan PhD , Yuan-Hung Wu PhD , Tzu-Yu Lai PhD , Yu-Mei Kang MD , Jui-Pin Chen MSc , Yu-Wen Hu PhD","doi":"10.1016/j.adro.2025.101863","DOIUrl":null,"url":null,"abstract":"<div><h3>Purpose</h3><div>This study aims to determine whether two-opposing-fields-per-day (2-fields-per-day) carbon ion radiation therapy for prostate cancer provides a significant advantage in terms of biologically effective dose (BED) for normal tissue compared to the one-alternating-field-per-day (1-field-per-day) approach.</div></div><div><h3>Methods and Materials</h3><div>The prescribed dose for carbon ion radiation therapy is 54 Gy (relative biological effectiveness [RBE]) in 12 fractions, and 10 patients were randomly selected for analysis. BED was calculated using 3 methods: the linear-quadratic model, modified microdosimetric kinetic model (mMKM) with a fixed clinical RBE of 2.41 (adopted in most treatment planning systems), and the mMKM without rescaling, using domain radius (<span><math><msub><mi>r</mi><mi>d</mi></msub></math></span>) values of 0.28, 0.38, and 0.45 µm with <span><math><mrow><mi>α</mi><mo>/</mo><mi>β</mi></mrow></math></span> ratios of 3, 5, and 10 Gy. Organs at risk (OARs) were contoured following standard guidelines. The dosimetric and dose-volume histogram differences, based on BEDs estimated using various methods, were compared between the 2-fields-per-day and 1-field-per-day approaches. Statistical analyses were performed using the Wilcoxon signed rank test with <em>P</em> < .05 considered statistically significant.</div></div><div><h3>Results</h3><div>The 2-fields-per-day approach resulted in significantly lower BED for noncentrally located OARs, particularly the femoral head, skin, and bone marrow. Among these, the femoral head showed the largest relative mean BED difference, with approximately 17% using the linear-quadratic model (<span><math><mrow><mi>α</mi><mo>/</mo><mi>β</mi></mrow></math></span>= 3 Gy), 7% with the mMKM model using a fixed clinical RBE, and 9% with the mMKM model (<span><math><msub><mi>r</mi><mi>d</mi></msub></math></span> = 0.38 µm, <span><math><mrow><mi>α</mi><mo>/</mo><mi>β</mi><mspace></mspace></mrow></math></span>= 3 Gy), with all <em>P</em> values <.01. In contrast, the differences observed for the obturator muscles and other centrally located OARs, including the urethra, bladder, and rectum, were minimal, with relative BED differences remaining below 3%.</div></div><div><h3>Conclusions</h3><div>Compared to the 1-field-per-day approach, the 2-fields-per-day approach results in lower BED for noncentrally located OARs, though significant variation is observed between the different methods used to estimate BED. The reduction in BED requires further investigation to evaluate its clinical significance and impact on toxicity.</div></div>","PeriodicalId":7390,"journal":{"name":"Advances in Radiation Oncology","volume":"10 11","pages":"Article 101863"},"PeriodicalIF":2.7000,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The Estimated Difference in Biologically Effective Dose Between Two-Opposing-Fields-Per-Day and One-Alternating-Field-Per-Day Carbon Ion Radiation Therapy for Prostate Cancer\",\"authors\":\"Chi-Chuan Chiou MD , Yu-Ming Liu PhD , Keng-Li Lan PhD , Yuan-Hung Wu PhD , Tzu-Yu Lai PhD , Yu-Mei Kang MD , Jui-Pin Chen MSc , Yu-Wen Hu PhD\",\"doi\":\"10.1016/j.adro.2025.101863\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><h3>Purpose</h3><div>This study aims to determine whether two-opposing-fields-per-day (2-fields-per-day) carbon ion radiation therapy for prostate cancer provides a significant advantage in terms of biologically effective dose (BED) for normal tissue compared to the one-alternating-field-per-day (1-field-per-day) approach.</div></div><div><h3>Methods and Materials</h3><div>The prescribed dose for carbon ion radiation therapy is 54 Gy (relative biological effectiveness [RBE]) in 12 fractions, and 10 patients were randomly selected for analysis. BED was calculated using 3 methods: the linear-quadratic model, modified microdosimetric kinetic model (mMKM) with a fixed clinical RBE of 2.41 (adopted in most treatment planning systems), and the mMKM without rescaling, using domain radius (<span><math><msub><mi>r</mi><mi>d</mi></msub></math></span>) values of 0.28, 0.38, and 0.45 µm with <span><math><mrow><mi>α</mi><mo>/</mo><mi>β</mi></mrow></math></span> ratios of 3, 5, and 10 Gy. Organs at risk (OARs) were contoured following standard guidelines. The dosimetric and dose-volume histogram differences, based on BEDs estimated using various methods, were compared between the 2-fields-per-day and 1-field-per-day approaches. Statistical analyses were performed using the Wilcoxon signed rank test with <em>P</em> < .05 considered statistically significant.</div></div><div><h3>Results</h3><div>The 2-fields-per-day approach resulted in significantly lower BED for noncentrally located OARs, particularly the femoral head, skin, and bone marrow. Among these, the femoral head showed the largest relative mean BED difference, with approximately 17% using the linear-quadratic model (<span><math><mrow><mi>α</mi><mo>/</mo><mi>β</mi></mrow></math></span>= 3 Gy), 7% with the mMKM model using a fixed clinical RBE, and 9% with the mMKM model (<span><math><msub><mi>r</mi><mi>d</mi></msub></math></span> = 0.38 µm, <span><math><mrow><mi>α</mi><mo>/</mo><mi>β</mi><mspace></mspace></mrow></math></span>= 3 Gy), with all <em>P</em> values <.01. In contrast, the differences observed for the obturator muscles and other centrally located OARs, including the urethra, bladder, and rectum, were minimal, with relative BED differences remaining below 3%.</div></div><div><h3>Conclusions</h3><div>Compared to the 1-field-per-day approach, the 2-fields-per-day approach results in lower BED for noncentrally located OARs, though significant variation is observed between the different methods used to estimate BED. The reduction in BED requires further investigation to evaluate its clinical significance and impact on toxicity.</div></div>\",\"PeriodicalId\":7390,\"journal\":{\"name\":\"Advances in Radiation Oncology\",\"volume\":\"10 11\",\"pages\":\"Article 101863\"},\"PeriodicalIF\":2.7000,\"publicationDate\":\"2025-07-21\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Advances in Radiation Oncology\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2452109425001502\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"ONCOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advances in Radiation Oncology","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2452109425001502","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ONCOLOGY","Score":null,"Total":0}
The Estimated Difference in Biologically Effective Dose Between Two-Opposing-Fields-Per-Day and One-Alternating-Field-Per-Day Carbon Ion Radiation Therapy for Prostate Cancer
Purpose
This study aims to determine whether two-opposing-fields-per-day (2-fields-per-day) carbon ion radiation therapy for prostate cancer provides a significant advantage in terms of biologically effective dose (BED) for normal tissue compared to the one-alternating-field-per-day (1-field-per-day) approach.
Methods and Materials
The prescribed dose for carbon ion radiation therapy is 54 Gy (relative biological effectiveness [RBE]) in 12 fractions, and 10 patients were randomly selected for analysis. BED was calculated using 3 methods: the linear-quadratic model, modified microdosimetric kinetic model (mMKM) with a fixed clinical RBE of 2.41 (adopted in most treatment planning systems), and the mMKM without rescaling, using domain radius () values of 0.28, 0.38, and 0.45 µm with ratios of 3, 5, and 10 Gy. Organs at risk (OARs) were contoured following standard guidelines. The dosimetric and dose-volume histogram differences, based on BEDs estimated using various methods, were compared between the 2-fields-per-day and 1-field-per-day approaches. Statistical analyses were performed using the Wilcoxon signed rank test with P < .05 considered statistically significant.
Results
The 2-fields-per-day approach resulted in significantly lower BED for noncentrally located OARs, particularly the femoral head, skin, and bone marrow. Among these, the femoral head showed the largest relative mean BED difference, with approximately 17% using the linear-quadratic model (= 3 Gy), 7% with the mMKM model using a fixed clinical RBE, and 9% with the mMKM model ( = 0.38 µm, = 3 Gy), with all P values <.01. In contrast, the differences observed for the obturator muscles and other centrally located OARs, including the urethra, bladder, and rectum, were minimal, with relative BED differences remaining below 3%.
Conclusions
Compared to the 1-field-per-day approach, the 2-fields-per-day approach results in lower BED for noncentrally located OARs, though significant variation is observed between the different methods used to estimate BED. The reduction in BED requires further investigation to evaluate its clinical significance and impact on toxicity.
期刊介绍:
The purpose of Advances is to provide information for clinicians who use radiation therapy by publishing: Clinical trial reports and reanalyses. Basic science original reports. Manuscripts examining health services research, comparative and cost effectiveness research, and systematic reviews. Case reports documenting unusual problems and solutions. High quality multi and single institutional series, as well as other novel retrospective hypothesis generating series. Timely critical reviews on important topics in radiation oncology, such as side effects. Articles reporting the natural history of disease and patterns of failure, particularly as they relate to treatment volume delineation. Articles on safety and quality in radiation therapy. Essays on clinical experience. Articles on practice transformation in radiation oncology, in particular: Aspects of health policy that may impact the future practice of radiation oncology. How information technology, such as data analytics and systems innovations, will change radiation oncology practice. Articles on imaging as they relate to radiation therapy treatment.