He couldn't wait to get out of there. Before leaving, he threw a coin into the beautiful fountain in front of the children's hospital and made this wish: "I wish I never, ever have to come back here again." But I think he's accepted the fact that he has to go back.
He is doing very well, though. He seems like his old self. He was running around the living room with Emily, having fun. He is eating normally, and feels well. When talking about when he has to go back to the hospital, he said "but, I don't feel sick."
The next cycle starts on June 17th. He shouldn't need to go back until then, unless he develops a fever and needs to be re-admitted and placed on antibiotics until his white blood cell counts come back up.