Inclusion Criteria:

- Any patient who will be treated to the brain or spinal axis for a CNS tum Patients so
treated will be stratified according to whether or not the hypo is included in the
treatment fields.

- Patients receiving external beam radiation to the brain may also be rece
chemotherapy or interferon-beta. (Add. #1, 11-9-95)

- Patients receiving high dose rate (stereotactic radiosurgery) are eligible.

- Patients must sign a study specific informed consent meeting all federal a
guidelines.

- Patients of any age, including children, are eligible (Add. #3, 11/25/97).

Exclusion Criteria:

- Patients who have a malignancy involving the hypothalamic-pituitary ax

- Patients who are not treated with irradiation to the brain or spinal axis.