Comprehensive evaluation of stereotactic radiotherapy plan for treatment of multiple brain metastatic tumors based on volume-modulated arc therapy and CyberKnife-6D Skull technology / 中华放射肿瘤学杂志

ABSTRACT

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.