Meet your doctor 
Whenever you are dealing with a life and death situation, discuss with your doctor and learn about diagnosis and prognosis, I mean the nature of illness or disease. 
No disease in the world carries 100 percent good prognosis. 
Do Not doubt your doctor, he needs confidence from you to fight this difficult situation . 
Help him ..help yourselves , after all, your doctor is just like you...
He is not God , he doesn't have a magic wand, he's just like you ...
As good as you are ..
As sincere as you are ..
Pray harder at such a time and your positivity will even help doctor to deal with such a critical situation.