Jiangxi University of Traditional Chinese Medicine, Nanchang, 330029, Jiangxi, China.
Tumor Hospital of Jiangxi Province, Nanchang, 330029, Jiangxi, China.
Comput Med Imaging Graph. 2016 Dec;54:1-5. doi: 10.1016/j.compmedimag.2016.10.001. Epub 2016 Oct 18.
This paper aims to compare dosimetric differences based on three types of radiotherapy plans for postoperative left breast cancer. In particular, based on a clinical dosimetric study, the three-dimensional conformal radiotherapy (3D-CRT), intensity- modulated radiation therapy (IMRT) and VMAT plans were implemented on 15 cases of postoperative patients with left breast cancer with prescription doses of 5000cGy.
Dose volume histogram (DVH) was used to analyze each evaluation index of clinical target volume (CTV) and organs at risk (OARs). Except for homogeneous index (HI), D, each CTV evaluation index of 3D-CRT plan was inferior to IMRT and VMAT plans (P<0.05). Compared with the VMAT plans, IMRT has a statistical significance only in D, V (P<0.05). On the contrary, D pertaining to the VMAT plan is much closer to the prescription dose with a V coverage rate as high as 97.44%. For the infected lung, V, V of 3D-CRT were the lowest (P<0.05), while V, V were the highest (P<0.05) among the three types of plans. Here, the V, V of infected lung were slightly higher (P<0.05) for the VMAT and IMRT plans. Each evaluation index of the contralateral lung and heart in 3D-CRT was the lowest (P<0.05). D of contralateral breast was lower in both IMRT and VMAT plans, which were 1770.89±121.16cGy and 1839.92±92.77cGy, respectively. While D of the spinal cord in IMRT and VMAT plans was higher, which were 1990.12±61.52cGy and 1927.38±43.67cGy, respectively. When the radiation dose of 500-1500cGy was delivered to the normal tissues, 3D-CRT significantly shows the lowest volume, VMAT is relatively higher. Monitor Units (MU) and treatment time (T) of VMAT were the least, only 49.33% and 55.86% of those of IMRT.
The three types of plans can meet the clinical dosimetry demands of postoperative radiotherapy for left breast cancer. The target of IMRT and VMAT plans has a better conformity, and the VMAT plan takes the advantages of less MU and treatment time.
本文旨在比较三种不同乳腺癌术后放疗计划的剂量学差异。特别地，基于一项临床剂量学研究，我们对 15 例接受左乳腺癌术后放疗的患者实施了三维适形放疗（3D-CRT）、调强放疗（IMRT）和容积旋转调强放疗（VMAT）计划，处方剂量为 5000cGy。
我们使用剂量体积直方图（DVH）分析了临床靶区（CTV）和危及器官（OARs）的每个评估指标。除均匀性指数（HI）和 D 外，3D-CRT 计划的每个 CTV 评估指标均劣于 IMRT 和 VMAT 计划（P<0.05）。与 VMAT 计划相比，IMRT 仅在 D 和 V 上具有统计学意义（P<0.05）。相反，VMAT 计划的 D 更接近处方剂量，其覆盖率高达 97.44%。对于受感染的肺，3D-CRT 的 V 和 V 最低（P<0.05），而三种计划中 V 和 V 最高（P<0.05）。在这里，VMAT 和 IMRT 计划的受感染肺的 V 和 V 略高（P<0.05）。3D-CRT 中对侧肺和心脏的每个评估指标最低（P<0.05）。对侧乳房的 D 在 IMRT 和 VMAT 计划中均较低，分别为 1770.89±121.16cGy 和 1839.92±92.77cGy。而 IMRT 和 VMAT 计划中脊髓的 D 较高，分别为 1990.12±61.52cGy 和 1927.38±43.67cGy。当 500-1500cGy 的辐射剂量输送到正常组织时，3D-CRT 显示出的体积最低，VMAT 相对较高。VMAT 的机器跳数（MU）和治疗时间（T）最少，分别为 IMRT 的 49.33%和 55.86%。
三种计划均能满足左乳腺癌术后放疗的临床剂量学要求。IMRT 和 VMAT 计划的靶区具有更好的适形性，而 VMAT 计划具有更少的 MU 和治疗时间的优势。
