Germinoma or Craniopharyngioma

My son Henry has had slow growth, diabetes insipidus, and vision loss (the latter of which led to an MRI and diagnosis) that is the result of a 5cm sized tumor in the area of his pituitary and hypothalamus. Blood tests revealed that most pituitary functions are normal. The initial thought was Craniopharyngioma, but another possibility is a Germinoma. A biopsy is needed to determine definitively.

So, Henry is scheduled for Brain surgery next March 14th at the Children's Hospital of Philadelphia. If the biopsy shows Craniopharygioma, surgery is continued to remove as much as possible/safe, with follow-up proton-beam radiation treatments. If the biopsy indicates Germinoma, he is immediately sewn back up and standard radiation is performed to deal with the Germinoma.

That's the background. I have a few questions, if people wouldn't mind chiming in ...

1.- Chemotherapy - To date there has been no mention of chemotherapy - is that not possible with someone so young (10 years old), or is it just not effective with these types of cancers, or have they just not mentioned it to us yet since we didn't ask and they probably didn't want to overwhelm us?

2.- Radiation late effects - I'm most worried about late effects of the radiation therapy ... that the cure may be worse than the disease. Is there some way to minimize the intensity and minimize collateral damage and still control the cancer? I'm particularly concerned about the pituitary gland.

3.- Hormonal functions - I've read that both types of cancer can disrupt the pituitary - but that the germinoma may be less malignant in this regard. Of course, the radiation treatment in either case seems to kill it. What I wondered is, particularly in the case of Germinoma, if a more advanced/localized type of radiation (proton beam or gamma knife or ???) though more expensive or perhaps not necessary to control the tumor might actually give better survival for the pituitary?

I, of course, will get definitive answers from the Dr. too, but wanted others' experiences if you have any.

Thanks very much !

Dan