Every year, tens of thousands of people have brain surgery without a single incision: there’s no scalpel, no operating table, and the patient loses no blood. Instead, this procedure uses a machine that emits invisible beams of light at a precise target inside the brain. So how exactly does this treatment work? And what does it do to the tumors it targets?

每年，数以万计的人在没有任何切口的情况下进行脑部手术：没有手术刀，没有手术台，病人没有失血。相反，这种手术使用一台机器，向大脑内的一个精确目标发射无形的光束。那么，这种治疗到底是如何工作的呢？它对目标肿瘤又有什么作用？