stupid question, is there no way to administer drugs directly where they are needed ?
There are several novel ways to deliver drugs to tumors in the brain in trials. Some use specially designed pumps, nanotechnology, and intra-arterial delivery (where a catheter is snaked to the tumor through blood vessels).
The problem is that all of these methods are experimental so they can't be used in combination. We're very hopeful that they are successful though!