METHODS: 17 cases of brain metastases were selected including 6 patients of single lesion and 11 patients of multiple lesions. Treatment plans of HyperArc and CyberKnife were designed in Eclipse 15.5 and Precision 1.0, respectively, and transferred to Velocity 3.2 for comparison.
RESULTS: HyperArc plans provided superior Conformity Index (0.91 ± 0.06 vs. 0.77 ± 0.07, p < 0.01) with reduced dose distribution in organs at risk (Dmax, p < 0.05) and lower normal tissue exposure (V4Gy-V20Gy, p < 0.05) in contrast to CyberKnife plans, although the Gradient Indexes were similar. CyberKnife plans showed higher Homogeneity Index (1.54 ± 0.17 vs. 1.39 ± 0.09, p < 0.05) and increased D2% and D50% in the target (p < 0.05). Additionally, HyperArc plans had significantly fewer Monitor Units (MUs) and beam-on time (p < 0.01).
CONCLUSIONS: HyperArc plans demonstrated superior performance compared with MLC-based CyberKnife plans in terms of conformity and the sparing of critical organs and normal tissues, although no significant difference in GI outcomes was noted. Conversely, CyberKnife plans achieved a higher target dose and HI. The study suggests that HyperArc is more efficient and particularly suitable for treating larger lesions in brain metastases.
方法:选择17例脑转移瘤患者,其中单发病灶6例,多发病灶11例。分别在Eclipse15.5和Precision1.0中设计了HyperArc和Cyberknife的治疗计划,并转移到Velocity3.2进行比较。
结果:HyperArc计划提供了优异的合格指数(0.91±0.06vs.0.77±0.07,p<0.01),在危险器官中剂量分布减少(Dmax,p<0.05)和较低的正常组织暴露(V4Gy-V20Gy,p<0.05)与射波刀计划相反,尽管梯度指数相似。射波刀计划显示出较高的均匀性指数(1.54±0.17vs.1.39±0.09,p<0.05),并增加了目标中的D2%和D50%(p<0.05)。此外,HyperArc计划具有显著更少的监测单位(MU)和波束开启时间(p<0.01)。
结论:与基于MLC的Cyberknife计划相比,HyperArc计划在符合性和保留关键器官和正常组织方面表现优异,尽管GI结局没有显著差异。相反,射波刀计划取得了较高的目标剂量和HI。研究表明,HyperArc更有效,特别适合治疗脑转移瘤中较大的病变。