Chinese Academy of Medical Sciences.
J Appl Clin Med Phys. 2014 May 8;15(3):4732. doi: 10.1120/jacmp.v15i3.4732.
This study aims to evaluate the possibility of using the technique of volume-modulated arc therapy (VMAT) to combine the advantages of simplified intensity-modulated radiation therapy (sIMRT) with that of regular intensity-modulated radiation therapy (IMRT) in upper esophageal cancer. Ten patients with upper esophageal carcinoma were randomly chosen in this retrospective study. sIMRT, IMRT, and VMAT plans were generated to deliver 60 Gy in 30 fractions to the planning target volume (PTV). For each patient, with the same clinical requirements (target dose prescription, and dose/dose-volume constraints to organs at risk (OARs)), three plans were designed for sIMRT (five equispaced coplanar beams), IMRT (seven equispaced coplanar beams), and VMAT (two complete arcs). Comparisons were performed for dosimetric parameters of PTV and of OARs (lungs, spinal cord PRV, heart and normal tissue (NT)). All the plans were delivered to a phantom to evaluate the treatment time. The Wilcoxon matched-pairs, signed-rank test was used for intragroup comparison. For all patients, compared to sIMRT plans, VMAT plans statistically provide: a) significant improvement in HI and CI for PTV; b) significant decrease in delivery time, lung V20, MLD, heart V30 and spinal cord PRV D1cc; c) significant increase in NT V5; and d) no significant reduction in lung V5, V10, and heart MD. For all patients, compared to IMRT plans, VMAT plans statistically provide: a) significant improvement in CI for PTV; b) significant decrease in delivery time, lung V20, MLD, NT and spinal cord PRV D1cc; c) significant increase in NT V5; and d) no significant reduction in HI for PTV, lung V5, V10, heart V30 and heart MD. For patients with upper esophageal carcinoma, using VMAT significantly reduces the delivery time and the dose to the lungs compared with IMRT, and consequently saves as much treatment time as sIMRT. Considering those significant advantages, compared to sIMRT and IMRT, VMAT is the first choice of radiotherapy techniques for upper esophageal carcinoma.
本研究旨在评估容积旋转调强放疗(VMAT)技术结合简化调强放疗(sIMRT)和常规调强放疗(IMRT)优势治疗上段食管癌的可能性。本回顾性研究中随机选择了 10 例上段食管癌患者。为每位患者生成了 sIMRT、IMRT 和 VMAT 计划,以 30 次分割给予计划靶区(PTV)60 Gy。对于每个患者,在相同的临床要求(靶剂量处方、危及器官(OAR)的剂量/剂量-体积限制)下,为 sIMRT(5 个等中心共面射束)、IMRT(7 个等中心共面射束)和 VMAT(2 个完整弧)设计了 3 个计划。对 PTV 和 OAR(肺、脊髓 PRV、心脏和正常组织(NT))的剂量学参数进行了比较。所有计划均输送至模体以评估治疗时间。采用 Wilcoxon 配对符号秩检验进行组内比较。对于所有患者,与 sIMRT 计划相比,VMAT 计划在统计学上提供:a)PTV 的 HI 和 CI 显著改善;b)治疗时间、肺 V20、MLD、心脏 V30 和脊髓 PRV D1cc 显著降低;c)NT V5 显著增加;d)肺 V5、V10 和心脏 MD 无显著减少。对于所有患者,与 IMRT 计划相比,VMAT 计划在统计学上提供:a)PTV 的 CI 显著改善;b)治疗时间、肺 V20、MLD、NT 和脊髓 PRV D1cc 显著降低;c)NT V5 显著增加;d)PTV 的 HI、肺 V5、V10、心脏 V30 和心脏 MD 无显著减少。对于上段食管癌患者,与 IMRT 相比,VMAT 可显著降低治疗时间和肺部剂量,从而节省与 sIMRT 相同的治疗时间。考虑到这些显著优势,与 sIMRT 和 IMRT 相比,VMAT 是上段食管癌放疗技术的首选。