Stereotactic intracavitary irradiation of cystic neoplasms of the brain.

Ten patients with intracranial cystic tumors underwent stereotactic intracavitary irradiation using 32P colloidal chromic phosphate. Accurate dosimetry (25,000-30,000 rad to the cast wall) was achieved by volume estimation using computed tomography. Between 1 and 15 months after surgery both craniopharyngioma and astrocytoma cysts regressed. Neurological, visual, and endocrinological deficits either stabilized or improved. Intracavitary irradiation should be the primary method of treating solitary cystic tumors of the brain.