基于VMAT与CK-6D Skull技术多发脑转移瘤立体定向放疗方案综合评价

Comprehensive evaluation of stereotactic radiotherapy plan for treatment of multiple brain metastatic tumors based on volume-modulated arc therapy and CyberKnife-6D Skull technology

目的对比容积调强弧形治疗(VMAT)和射波刀六维颅骨追踪(CK-6D Skull)技术治疗多发脑转移瘤的立体定向放疗(SRT)方案的综合差异,探索颅内多靶点采用何种技术更具优势。方法回顾性分析2017-2018年间,≥2个脑转移灶接受SRT患者42例,分别对每例患者选择CK-6D Skull技术和VMAT技术设计放疗计划;通过统计靶区梯度指数、剂量跌落体积和危及器官等参数比较VMAT与CK-6D Skull的计划质量;记录总机器跳数和单次治疗时间比较两种技术执行效率。结果颅内2靶点与3靶点计划的梯度指数CK-6D Skull技术优于VMAT技术(P<0.05);颅内4靶点和5靶点两组计划的梯度指数差异不大(P>0.05);两种技术对于危及器官最大剂量的贡献差别不大(P>0.05),但VMAT技术治疗时间更短(P<0.05)。结论两种技术均能满足临床开展SRT多发脑转移瘤的要求,单从治疗计划和执行的角度,建议颅内<4个转移瘤患者考虑采用CK-6D Skull技术实施SRT,≥4个转移瘤考虑采用VMAT技术实施SRT;体质状况差,不易长时间保持固定体位的患者优先考虑VMAT技术。对于两种技术在实施颅内多发脑转移瘤SRT更多的差异,有待更多的病例资料进行统计研究。

Objective By comparing the comprehensive differences between volume-modulated arc therapy(VMAT)-and CyberKnife-6D Skull(CK-6D Skull)tracking technology-based stereotactic radiotherapy(SRT)plans in the treatment of multiple brain metastatic tumors,and explore the advantages of multi-target intracranial technology.Methods Clinical data of 42 patients with more than 2 brain metastases who received STR between January 2017 and August 2018 were retrospectively analyzed.For each patient,two radiotherapy plans were designed by selecting CK-6D Skull and VMAT technologies.The quality of VMAT and CK-6D Skull was compared by calculating the gradient index(GI),dose sag volume and organ at risk(OAR)of target area.The total number of monitor unit and single treatment time were recorded to compare the execution efficiency of these two technologies.Results The GI of intracranial 2-target and 3-target plans of CK-6D Skull technology was significantly superior to that of VMAT technology(P<0.05).The GI did not significantly differ between the 4-target and the 5-target groups(P>0.05).The contribution of these two technologies to the maximum dose of OAR was not significantly different(P>0.05),whereas the treatment time of VMAT technology was shorter(P<0.05).Conclusions Both technologies can meet the requirements of clinical SRT for multiple brain metastatic tumors.From the perspective of treatment plan and implementation,SRT based on CK-6D skull technology is recommended for patients with less than 4 intracranial metastatic tumors,and VMAT-based SRT is considered for those with>4 metastatic tumors.Patients with poor physical condition and difficulty in maintaining a fixed position for a long time shall give priority to VMAT technology.More differences between these two technologies in the implementation of SRT for intracranial multiple brain metastases remain to be elucidated by more case data for statistical analysis.