why are you starting radiation? just curious....without any radiation, my brain tumors shrank significantly on tagrisso alone. i did have 5 rounds of radiation back in november because small amounts of edema managed to envelop several of my brain tumors, thus rendering the tagrisso not working as effectively on those particular tumors. they were slowly growing because of the edema. apparently, tagrisso has a hard time crossing fluid. i put myself on a low dose of mag sulfate and seemingly have not had a problem since. don't really know if the mag sulfate is working or it's just plain ole luck that, so far, no edema has returned. teresa