Impact of deep inspiration breath-hold (DIBH) on dose distribution and radiobiological effects in left-sided breast irradiation: A comparative study of IMRT and VMAT techniques under DIBH and free breathing conditions
{"title":"Impact of deep inspiration breath-hold (DIBH) on dose distribution and radiobiological effects in left-sided breast irradiation: A comparative study of IMRT and VMAT techniques under DIBH and free breathing conditions","authors":"Weiwei Wu , Qungui Zhang , Hui Yin , Zhiwei Liu , Fangfang Xie","doi":"10.1016/j.jrras.2025.101912","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><div>Radiotherapy for left-sided breast cancer faces challenges in sparing cardiac structures due to anatomical proximity. Deep inspiration breath-hold (DIBH) and advanced techniques like VMAT offer potential solutions, but their synergistic effects on dose distribution and radiobiological outcomes require comprehensive evaluation.</div></div><div><h3>Objective</h3><div>To compare the dosimetric and radiobiological differences between various radiotherapy techniques (VMAT vs. IMRT) under different respiratory modes (DIBH vs. FB) for left breast cancer patients after breast-conserving surgery.</div></div><div><h3>Methods</h3><div>This retrospective study analyzed 27 left breast cancer patients treated between May 2023 and October 2024. CT scans were acquired under both FB and DIBH conditions for each patient. Three half-beam radiotherapy plans were designed: D-IMRT (DIBH-IMRT), D-VMAT (DIBH-VMAT), and F-VMAT (FB-VMAT). Dosimetric evaluation included Conformity Index (CI) and Homogeneity Index (HI) for targets alongside dose-volume parameters for OARs (heart, LAD, bilateral lungs) derived from Dose-volume histogram (DVHs). Radiobiological assessment employed: 1) Niemierko-based Tumor Control Probability (TCP), 2) Lyman-Kutcher-Burman Normal Tissue Complication Probability (NTCP) for cardiac/left lung tissues, and 3) linear model-derived Excess Absolute Risk (EAR) for contralateral breast.</div></div><div><h3>Results</h3><div>DIBH significantly increased left lung volume by 799.2 cm<sup>3</sup> (<em>p</em> < 0.001) and heart-chest wall distance by 1.3 cm (<em>p</em> < 0.001). All plans achieved comparable target coverage and homogeneity. Compared with D-IMRT, D-VMAT demonstrated superior target conformity (PTV: 0.870 vs. 0.827; PTV_Bed: 0.775 vs. 0.757, <em>p</em> < 0.05), reduced monitor units by 47.6 % (618 vs. 1179, <em>p</em> < 0.001), and significantly lowered cardiac doses (V5 %: 5.82 % vs. 11.83 %; V20 %: 0.16 % vs. 0.58 %; mean dose: 1.92 Gy vs. 2.57 Gy, <em>p</em> < 0.05) with corresponding NTCP reduction (1.93E-11 vs. 6.61E-11, <em>p</em> < 0.003). However, D-VMAT increased contralateral breast exposure (V5 %: 5.60 % vs. 1.72 %; mean dose: 1.45 Gy vs. 0.71 Gy) and EAR (152.82 vs. 55.63, <em>p</em> < 0.001). Compared with F-VMAT, D-VMAT further reduced cardiac doses (V5 %: 5.82 % vs. 13.27 %; V20 %: 0.16 % vs. 5.2 %; mean dose: 1.92 Gy vs. 3.83 Gy; NTCP: 1.93E-11 vs. 8.77E-11, <em>p</em> < 0.001) and left lung V20 % (11.15 % vs. 13.43 %, <em>p</em> < 0.001).</div></div><div><h3>Conclusion</h3><div>DIBH-VMAT synergistically reduces cardiac and pulmonary radiation exposure while maintaining target coverage, albeit with increased contralateral breast dose. Clinical implementation requires careful risk-benefit assessment for personalized radiotherapy.</div></div>","PeriodicalId":16920,"journal":{"name":"Journal of Radiation Research and Applied Sciences","volume":"18 4","pages":"Article 101912"},"PeriodicalIF":2.5000,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Radiation Research and Applied Sciences","FirstCategoryId":"103","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1687850725006247","RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MULTIDISCIPLINARY SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Background
Radiotherapy for left-sided breast cancer faces challenges in sparing cardiac structures due to anatomical proximity. Deep inspiration breath-hold (DIBH) and advanced techniques like VMAT offer potential solutions, but their synergistic effects on dose distribution and radiobiological outcomes require comprehensive evaluation.
Objective
To compare the dosimetric and radiobiological differences between various radiotherapy techniques (VMAT vs. IMRT) under different respiratory modes (DIBH vs. FB) for left breast cancer patients after breast-conserving surgery.
Methods
This retrospective study analyzed 27 left breast cancer patients treated between May 2023 and October 2024. CT scans were acquired under both FB and DIBH conditions for each patient. Three half-beam radiotherapy plans were designed: D-IMRT (DIBH-IMRT), D-VMAT (DIBH-VMAT), and F-VMAT (FB-VMAT). Dosimetric evaluation included Conformity Index (CI) and Homogeneity Index (HI) for targets alongside dose-volume parameters for OARs (heart, LAD, bilateral lungs) derived from Dose-volume histogram (DVHs). Radiobiological assessment employed: 1) Niemierko-based Tumor Control Probability (TCP), 2) Lyman-Kutcher-Burman Normal Tissue Complication Probability (NTCP) for cardiac/left lung tissues, and 3) linear model-derived Excess Absolute Risk (EAR) for contralateral breast.
Results
DIBH significantly increased left lung volume by 799.2 cm3 (p < 0.001) and heart-chest wall distance by 1.3 cm (p < 0.001). All plans achieved comparable target coverage and homogeneity. Compared with D-IMRT, D-VMAT demonstrated superior target conformity (PTV: 0.870 vs. 0.827; PTV_Bed: 0.775 vs. 0.757, p < 0.05), reduced monitor units by 47.6 % (618 vs. 1179, p < 0.001), and significantly lowered cardiac doses (V5 %: 5.82 % vs. 11.83 %; V20 %: 0.16 % vs. 0.58 %; mean dose: 1.92 Gy vs. 2.57 Gy, p < 0.05) with corresponding NTCP reduction (1.93E-11 vs. 6.61E-11, p < 0.003). However, D-VMAT increased contralateral breast exposure (V5 %: 5.60 % vs. 1.72 %; mean dose: 1.45 Gy vs. 0.71 Gy) and EAR (152.82 vs. 55.63, p < 0.001). Compared with F-VMAT, D-VMAT further reduced cardiac doses (V5 %: 5.82 % vs. 13.27 %; V20 %: 0.16 % vs. 5.2 %; mean dose: 1.92 Gy vs. 3.83 Gy; NTCP: 1.93E-11 vs. 8.77E-11, p < 0.001) and left lung V20 % (11.15 % vs. 13.43 %, p < 0.001).
Conclusion
DIBH-VMAT synergistically reduces cardiac and pulmonary radiation exposure while maintaining target coverage, albeit with increased contralateral breast dose. Clinical implementation requires careful risk-benefit assessment for personalized radiotherapy.
背景:左侧乳腺癌的放射治疗由于解剖学上的接近,在保留心脏结构方面面临着挑战。深度吸气屏气(DIBH)和VMAT等先进技术提供了潜在的解决方案,但它们对剂量分布和放射生物学结果的协同效应需要全面评估。目的比较左乳腺癌保乳术后不同呼吸方式(DIBH vs FB)下不同放疗方式(VMAT vs IMRT)的剂量学和放射生物学差异。方法回顾性分析2023年5月至2024年10月间接受治疗的27例左乳腺癌患者。每位患者在FB和DIBH条件下均进行CT扫描。设计了三种半束放疗方案:D-IMRT (DIBH-IMRT)、D-VMAT (DIBH-VMAT)和F-VMAT (FB-VMAT)。剂量学评估包括靶标的符合性指数(CI)和均匀性指数(HI),以及OARs(心脏、LAD、双侧肺)的剂量-体积参数,这些参数来自剂量-体积直方图(DVHs)。放射生物学评估采用:1)niemierko肿瘤控制概率(TCP), 2) Lyman-Kutcher-Burman正常组织并发症概率(NTCP)(心脏/左肺组织),3)线性模型衍生的对侧乳房超额绝对风险(EAR)。结果dibh使左肺容积增加799.2 cm3 (p < 0.001),心胸壁距离增加1.3 cm (p < 0.001)。所有计划都实现了可比的目标覆盖率和同质性。与D-IMRT相比,D-VMAT表现出更好的目标符合性(PTV: 0.870 vs. 0.827; PTV_Bed: 0.775 vs. 0.757, p < 0.05),减少了47.6%的监测单位(618 vs. 1179, p < 0.001),显著降低了心脏剂量(V5 %: 5.82% vs. 11.83%; V20 %: 0.16% vs. 0.58%;平均剂量:1.92 Gy vs. 2.57 Gy, p < 0.05),相应的NTCP降低(1.93E-11 vs. 6.61E-11, p < 0.05)。然而,D-VMAT增加了对侧乳房暴露(v5%: 5.60% vs. 1.72%;平均剂量:1.45 Gy vs. 0.71 Gy)和EAR (152.82 vs. 55.63, p < 0.001)。与F-VMAT相比,D-VMAT进一步降低心脏剂量(v5%: 5.82% vs. 13.27%; v20%: 0.16% vs. 5.2%;平均剂量:1.92 Gy vs. 3.83 Gy; NTCP: 1.93E-11 vs. 8.77E-11, p < 0.001)和左肺v20% (11.15% vs. 13.43%, p < 0.001)。结论dibh - vmat可协同减少心脏和肺部辐射暴露,同时保持靶覆盖,尽管对侧乳房剂量增加。临床实施需要对个体化放疗进行仔细的风险-收益评估。
期刊介绍:
Journal of Radiation Research and Applied Sciences provides a high quality medium for the publication of substantial, original and scientific and technological papers on the development and applications of nuclear, radiation and isotopes in biology, medicine, drugs, biochemistry, microbiology, agriculture, entomology, food technology, chemistry, physics, solid states, engineering, environmental and applied sciences.