Radiotherapy of primary intracranial germinomas: the case against routine craniospinal irradiation

Abstract

A retrospective study was performed on all patients with biopsy-proven intracranial germinomas and unbiopsied suprasellar or pineal region tumors treated during the past 30 years in the Department of Radiation Oncology, University of California, San Francisco. A total of 33 patients were treated: 13 with biopsy-proven germinomas, and 20 others who were unbiopsied. All patients were treated with megavoltage equipment; total dose varied between 40-55 Gy. Only two patients were treated with prophylactic spinal irradiation. No patient received initial or adjuvant chemotherapy. Follow-up times for biopsy-proven patients ranged from 0.5 to 16.7 years with a median 5.3 years. No biopsy-proven patient had a recurrence of the tumor or died; thus, actuarial relapse-free and determinate survivals at 5 years were 100%. Although only one patient in this group received prophylactic spinal irradiation, no patient failed in the spinal axis. The 20 unbiopsied patients had follow-up times ranging from 0.1 to 27.5 years with a median of 5.5 years. Six unbiopsied patients died: two from recurrent disease at the primary site, one from distant peritoneal metastases, two from complications of treatment, and one from intercurrent disease. For this group, actuarial relapse-free survival at 5 years was 72%; the corresponding determinate survival was 73%. Nineteen unbiopsied patients were treated without craniospinal irradiation. Only one developed spinal metastases. The results from this and other series indicate that the risk of spinal metastases from intracranial germinoma is too low to warrant routine prophylactic spinal irradiation. However, patients with gross tumor spill causing contamination of the CSF, malignant CSF cytology, or documented subependymal or subarachnoid metastases presumably are at higher risk for leptomeningeal failure. Craniospinal irradiation is recommended for these patients.