<正>1故障现象执行容积弧形调强放射治疗(volumetric modulated arc therapy,VMAT)时,机架旋转到340°至60°之间报多叶光栅(multi-leaf collimators,MLC)联锁。2故障分析加速器型号为瓦里安i X,MLC型号为瓦里安MLC-120[1,2]。出现该故障时查看MLC的位置,发现叶