Yin Yong, Ma Changsheng, Gao Min, Chen Jinhu, Ma Yidong, Liu Tonghai, Lu Jie, Yu Jinming
School of Information Science and Engineering of Shandong University, Shandong Province, China.
Med Dosim. 2011 Winter;36(4):448-54. doi: 10.1016/j.meddos.2010.12.001. Epub 2011 Apr 7.
We wanted to compare the dosimetric difference and treatment efficiency of RapidArc and fixed gantry intensity-modulated radiotherapy treatment (IMRT) for multiple liver metastases. Computed tomography datasets of 10 patients were studied retrospectively. IMRT plans were generated using 5 fields and RapidArc using either 1 or 2 arcs. The dose distribution of planning target volume (PTV), organs at risk (OARs), and the normal tissue were compared. Monitor units and treatment time were scored to measure expected treatment efficiency. Both RapidArc and IMRT plans resulted in equivalent target coverage. There was no statistically significant difference for the maximum and the minimum dose of PTV. RapidArc plans achieved an improved conformity index compared with IMRT (RA1 = 1.68 ± 0.27, RA2 = 1.61 ± 0.25, IMRT = 1.80 ± 0.37). For OARs, all techniques respected planning objectives. RapidArc plans had a lower dose in V(40) of small bowel than IMRT, but were higher in mean dose of kidneys. Concerning the V(5), V(10), and V(15) of healthy tissue, RapidArc plans were higher than IMRT. However, the V(20), V(25), and V(30) of healthy tissue in RapidArc plans were lower than IMRT. Monitor units per fraction of RapidArc plans were about 40% or 46% of IMRT. Compared with IMRT plans, treatment time of RapidArc plans were reduced by 60% or 70%. All techniques respected planning objectives. RapidArc showed statistical improvements in conformity index and healthy tissue sparing with uncompromised target coverage. This, in combination with fewer monitor units and short delivery time, can lead to clinically significant advances for the treatment of multiple liver metastases.
我们想要比较容积旋转调强放疗（RapidArc）与固定机架调强放疗（IMRT）在治疗多发肝转移瘤时的剂量学差异和治疗效率。回顾性研究了10例患者的计算机断层扫描数据集。IMRT计划采用5野生成，RapidArc计划采用1个或2个弧生成。比较了计划靶区（PTV）、危及器官（OARs）和正常组织的剂量分布。对监测单位和治疗时间进行评分以衡量预期的治疗效率。RapidArc计划和IMRT计划均能实现等效的靶区覆盖。PTV的最大剂量和最小剂量无统计学显著差异。与IMRT相比，RapidArc计划的适形指数有所提高（RA1 = 1.68 ± 0.27，RA2 = 1.61 ± 0.25，IMRT = 1.80 ± 0.37）。对于OARs，所有技术均符合计划目标。RapidArc计划中小肠V(40)的剂量低于IMRT，但肾脏的平均剂量高于IMRT。关于健康组织的V(5)、V(10)和V(15)，RapidArc计划高于IMRT。然而，RapidArc计划中健康组织的V(20)、V(25)和V(30)低于IMRT。RapidArc计划每分次的监测单位约为IMRT的40%或46%。与IMRT计划相比，RapidArc计划的治疗时间减少了60%或70%。所有技术均符合计划目标。RapidArc在适形指数和保护健康组织方面有统计学改善，且不影响靶区覆盖。这与较少的监测单位和较短的照射时间相结合，可为多发肝转移瘤的治疗带来具有临床意义的进展。
