My sister was diagnosed with a glioblastoma, the very large mass was removed during a 9 hour surgery, with no deficits. She will start radiation and oral chemotherapy drug, and they want to also start a clinical study at the same time, I am concerned that is alot at one time, also her surgeon did no want her to have alot of radiation,but one clincal study is a large amount of radiation, i am also concerned about too much radiation to the brain that it may have bad side effects.I am also not sure exactly what a clincal trail is. is it experimental? Thanks Linda