sheila's Journey with Medulloblastoma

I have been caring for my son who has been diagnosed with stage 3 Medulloblastoma since the end of March 2012. He has 2 craniotomies, 6 weeks of radiation, surgery for a G-tube, and is starting his 2nd of 6 rounds of chemotherapy. Because he had a golfball sze tumor in his brain and 3 small tumors on his spine, his prognosis is less tan 50% chance of survival. Along with regular treatment protocol, he is participating in clinical trials. We have been told that this paricular cancer is unique in that there is no remission. He is either 100% cured, or does not survive. Every week that goes by brings more side effects from the treatments including life threatening permanent health issues. I struggle with the fact that he may not survive the treatments before he is cured.

At what point should I say enough is enough? I will always maintain hope for the cure.What if he is cured and has to spend the rest of his life with miserable dibilitating medical issues caused from treatment?