Radiation therapy for primary intracranial germ-cell tumors

Abstract

Purpose: To evaluate the diagnosis, therapy, and survival of patients with intracranial germ-cell tumors. To define the role of prophylactic craniospinal irradiation and chemotherapy necessary to impact on survival.

Methods and materials: Forty-eight patients with surgically confirmed or suspected primary intracranial germ-cell tumors treated at UCSF between 1968-1990 were reviewed. Thirty-four patients had a pathologic diagnosis, including 24 germinomas, 3 malignant teratomas, 2 choriocarcinomas, 1 embryonal carcinoma, 1 endodermal sinus tumor, and 3 mixed tumors. Information obtained included histology, location, cerebrospinal fluid (CSF) cytology, alpha-fetoprotein (AFP), and beta-human chorionic gonadotropin (B-HCG), metastatic evaluation, radiation details, survival, and sites of failure. Minimum follow-up time was 2 years and ranged to a maximum of 24 years, with a median of 8 years.

Results: Median age at diagnosis was 16 years with 36 males and 12 females. Ten of 32 patients had elevated B-HCG at diagnosis; 6 of 29 had elevations of AFP. Cerebrospinal fluid cytology was negative in 35 of 36 patients evaluated; myelography or spinal MRI was positive in only 1 of 31 patients studied. Five-year actuarial disease-free survival after irradiation was 91% for germinomas, 63% for unbiopsied tumors, and 60% for nongerminoma germ-cell tumors with doses of 50-54 Gy to the local tumor site with or without whole-brain or whole-ventricular irradiation. Routine prophylactic cranio-spinal axis irradiation was not given with a spinal only failure rate of 2%. Eleven of 48 patients have expired, with an actuarial 5-year survival rate of 100% for germinomas, 79% for nonbiopsied tumors, and 80% for nongerminoma germ-cell tumors.

Conclusion: With complete diagnostic craniospinal evaluation, spinal irradiation is not necessary. Cure rates for germinomas are excellent with irradiation alone. Multidrug chemotherapy is necessary with irradiation for nongerminoma germ-cell tumors. Histology is the most important prognostic factor; therefore, all patients should have surgical conformation of their diagnosis so that appropriate treatment can be given.