Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada.
Phys Med Biol. 2010 Feb 21;55(4):1231-41. doi: 10.1088/0031-9155/55/4/022. Epub 2010 Feb 2.
Three intensity-modulated tangential beam radiotherapy plan types for breast cancer treatment were evaluated based on PTV homogeneity index (HI) and equivalent uniform dose (EUD), heart V30 and EUD, whole lung V20 and EUD, and typical planning time compared to conventional 2D plans. 20 early-stage breast cancer patients were CT-scanned in the supine position, and tangential field extent, gantry and collimator angles were chosen. Four treatment plans were created for each patient: conventional, dynamically wedged plan based on the dose distribution on the central axial slice; forward planned IMRT; surface compensated plan created using an Eclipse tool and hybrid IMRT plan combining open and inverse-optimized fields. All three IMRT planning techniques represent significant improvement in PTV HI and EUD compared to conventional plans. Among the IMRT plans, the hybrid IMRT plan produced the best HI. IMRT lowered heart V30 and lung V20, but no significant differences in heart or lung EUD were detected between IMRT techniques. The IMRT technique with the shortest planning time was the compensated plan, followed by the hybrid IMRT. IMRT planning provides dosimetric benefits in breast cancer patients. The selection of the most appropriate IMRT technique must include careful consideration of the resources available.
基于 PTV 均匀性指数（HI）和等效均匀剂量（EUD）、心脏 V30 和 EUD、全肺 V20 和 EUD 以及与常规二维计划相比的典型规划时间，评估了三种用于乳腺癌治疗的调强切线束放疗计划类型。对 20 例早期乳腺癌患者进行仰卧位 CT 扫描，并选择切线野范围、机架和准直器角度。为每位患者创建了 4 种治疗计划：常规计划、基于中央轴位切片上剂量分布的动态楔形计划；正向计划调强放疗；使用 Eclipse 工具创建的表面补偿计划以及结合开放和逆优化场的混合调强放疗计划。与常规计划相比，所有三种调强放疗计划技术均显著提高了 PTV HI 和 EUD。在调强放疗计划中，混合调强放疗计划产生了最佳 HI。调强放疗降低了心脏 V30 和肺 V20，但在心脏或肺 EUD 方面，不同调强放疗技术之间没有发现显著差异。规划时间最短的调强放疗技术是补偿计划，其次是混合调强放疗。调强放疗为乳腺癌患者提供了剂量学优势。选择最合适的调强放疗技术必须包括仔细考虑可用资源。
