Medulloblastoma in adults: improved survival with supervoltage radiation therapy.

During the period from January 1962--June 1979, 17 adults (greater than or equal to 16 years of age) received postoperative supervoltage neuraxis radiation therapy for medulloblastoma. An actuarial five- and ten-year survival rate of 46% was achieved, and the major site of recurrence postirradiation was in the posterior fossa. Compared to previous pediatric series, adults may demonstrate more visceral metastases and fare less well after tumor recurrence. Compared to prior series of adult patients, the demonstrated improved survival is attributed to increased doses delivered to the posterior fossa.