Evaluating Potential Dosimetric Advantage of Integrating Highly Conformal Target Delineation with VMAT Compared to Conventional Flank Irradiation for Wilms Tumors

IF 6.4 1区医学 Q1 ONCOLOGY

International Journal of Radiation Oncology Biology Physics Pub Date : 2025-02-03 DOI:10.1016/j.ijrobp.2024.11.050

T. Ali , M. Khan , M. Umer , M. Tariq , B. Qureshi

{"title":"Evaluating Potential Dosimetric Advantage of Integrating Highly Conformal Target Delineation with VMAT Compared to Conventional Flank Irradiation for Wilms Tumors","authors":"T. Ali , M. Khan , M. Umer , M. Tariq , B. Qureshi","doi":"10.1016/j.ijrobp.2024.11.050","DOIUrl":null,"url":null,"abstract":"<div><h3>Objectives</h3><div>Conventionally flank irradiation for Wilms tumor typically utilized anteroposterior (AP-PA) photon beams. However, recent publications prioritize precise flank target volume delineation following SIOP Renal Tumor Study Group (RTSG) consensus protocol taking postoperative organ shifts and intrafractional motion into consideration. This study aims to evaluate the dosimetric advantage of Volumetric Modulated Arc Therapy (VMAT) versus conventional AP/PA technique for Wilms tumor.</div></div><div><h3>Method</h3><div>Patients with stage II and III High-risk Wilms tumors referred for postoperative radiotherapy were included. Dosimetric analysis was conducted retrospectively on eight cases. For each patient, separate target volumes were delineated for highly conformal and conventional treatment plans, employing VMAT for highly conformal and AP/PA for conventional volumes. All cases were planned preceding mandatory peer review. A dose of 2520cGy/14fraction was prescribed as per SIOP High-Risk Wilms tumor protocol. Planning target volume (PTV) in cm3, mean doses to the liver, small bowel, contralateral kidney, and spleen were calculated and subsequently compared.</div></div><div><h3>Results</h3><div>Five (n=10) right-sided and three(n=6) left-sided flank volumes were included. In the study, highly conformal volumes planned via VMAT demonstrated a reduction in PTV compared to conventional volumes, 629.04 cm³ vs. 798.8 cm³ respectively. Mean dose reduction favoring highly conformal target volumes was observed for mean of all OARs, including liver (942.5 cGy conformal vs. 1264 cGy conventional), contralateral kidney (258.6 cGy conformal vs. 294.2 cGy conventional), small bowel (1114.7 cGy conformal vs. 1411.7 cGy conventional), and spleen (1401cGy conformal vs. 1990cGy conventional). VMAT provided greater dose sparing to normal structures as compared to AP/PA techniques.</div></div><div><h3>Conclusion</h3><div>Compared to conventional AP/PA photon beams, flank irradiation, employing highly conformal flank target volumes with VMAT resulted in reduced doses to the OARs, while still maintaining acceptable organ doses in the AP/PA plan highlighting the value of peer review in ensuring radiation quality, and dosimetric benefits.</div></div>","PeriodicalId":14215,"journal":{"name":"International Journal of Radiation Oncology Biology Physics","volume":"121 3","pages":"Page e14"},"PeriodicalIF":6.4000,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Radiation Oncology Biology Physics","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0360301624036241","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ONCOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

Objectives

Conventionally flank irradiation for Wilms tumor typically utilized anteroposterior (AP-PA) photon beams. However, recent publications prioritize precise flank target volume delineation following SIOP Renal Tumor Study Group (RTSG) consensus protocol taking postoperative organ shifts and intrafractional motion into consideration. This study aims to evaluate the dosimetric advantage of Volumetric Modulated Arc Therapy (VMAT) versus conventional AP/PA technique for Wilms tumor.

Method

Patients with stage II and III High-risk Wilms tumors referred for postoperative radiotherapy were included. Dosimetric analysis was conducted retrospectively on eight cases. For each patient, separate target volumes were delineated for highly conformal and conventional treatment plans, employing VMAT for highly conformal and AP/PA for conventional volumes. All cases were planned preceding mandatory peer review. A dose of 2520cGy/14fraction was prescribed as per SIOP High-Risk Wilms tumor protocol. Planning target volume (PTV) in cm3, mean doses to the liver, small bowel, contralateral kidney, and spleen were calculated and subsequently compared.

Results

Five (n=10) right-sided and three(n=6) left-sided flank volumes were included. In the study, highly conformal volumes planned via VMAT demonstrated a reduction in PTV compared to conventional volumes, 629.04 cm³ vs. 798.8 cm³ respectively. Mean dose reduction favoring highly conformal target volumes was observed for mean of all OARs, including liver (942.5 cGy conformal vs. 1264 cGy conventional), contralateral kidney (258.6 cGy conformal vs. 294.2 cGy conventional), small bowel (1114.7 cGy conformal vs. 1411.7 cGy conventional), and spleen (1401cGy conformal vs. 1990cGy conventional). VMAT provided greater dose sparing to normal structures as compared to AP/PA techniques.

Conclusion

Compared to conventional AP/PA photon beams, flank irradiation, employing highly conformal flank target volumes with VMAT resulted in reduced doses to the OARs, while still maintaining acceptable organ doses in the AP/PA plan highlighting the value of peer review in ensuring radiation quality, and dosimetric benefits.

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

International Journal of Radiation Oncology Biology Physics 医学-核医学

CiteScore

11.00

自引率

7.10%

发文量

2538

审稿时长

6.6 weeks

期刊介绍： International Journal of Radiation Oncology • Biology • Physics (IJROBP), known in the field as the Red Journal, publishes original laboratory and clinical investigations related to radiation oncology, radiation biology, medical physics, and both education and health policy as it relates to the field. This journal has a particular interest in original contributions of the following types: prospective clinical trials, outcomes research, and large database interrogation. In addition, it seeks reports of high-impact innovations in single or combined modality treatment, tumor sensitization, normal tissue protection (including both precision avoidance and pharmacologic means), brachytherapy, particle irradiation, and cancer imaging. Technical advances related to dosimetry and conformal radiation treatment planning are of interest, as are basic science studies investigating tumor physiology and the molecular biology underlying cancer and normal tissue radiation response.