What do you mean by 'any evidence that works better Than alternatives'?

It can deliver radiations to the brain that will peak at the exact position of the cancer, and reduce irradiation in sane tissues. The 'better' is 'less irradiation to sane tissues' that in turn reduces the risk for new cancers.

Note: I'm not expert on the matter, but I had technical visits to IBA and know several PhDs that work there

> What do you mean by 'any evidence that works better Than alternatives'?

I mean exactly that, clinical trials demonstrating that proton therapy is superior to radiation therapy. This is not a question about the physics but about how patients respond (and whether the expense of delivering proton therapy outweighs the expected marginal benefits).