CEREBELLAR MEDULLOBLASTOMAS IN ADULTS

Between 1981 and 1991, 11 adults over 16 years of age were treated for medulloblastoma at the authors' institutions. These patients were stu died retrospectively. The patients were managed uniformly, and the tre atment included extensive surgical resections and radiation therapy. C hemotherapy was used on only three patients with recurrence. Probable prognostic factors, including tumor location, extent of surgical resec tion, dose and extent of radiation therapy, and histological character istics of the tumor such as neuronal or glial differentiation and desm oplasia were investigated. The classical form of medulloblastoma was p resent in seven cases while the desmoblastic subtype was found in four cases. All patients with the desmoplastic form had the tumor in cereb ellar hemisphere. Gross total removal of the tumor was achieved in sev en patients and subtotal excision in four patients. There was no surgi cal mortality in our series. The extent of surgical resection and loca tion of the tumor had an important effect on longterm survival. The ex tent and dose of radiation therapy had a major effect on recurrence-fr ee survival. Survival rates were best for patients receiving high-dose irradiation to the entire neuroaxis. Other factors such as age and se x had no major effect on prognosis.