[Radiotherapy of intracranial germinomas]

Between 1978 and 1988, 28 patients with intracranial germinoma, verified or presumed, were treated with radiation. The diagnosis was made based on histology in 6 cases, on cerebrospinal fluid (CSF) cytology in 2 cases and on clinical (response to radiation) and radiological findings in the remaining 20 cases. The target volume was the primary site plus whole brain in 23 cases, whole brain in 4 cases and the primary site only in 1 case. Whole spinal irradiation was undertaken for 14 patients, including 9 patients of high risk group, i.e., with positive findings in CSF cytology, suspected subarachnoid space seeding, multifocal tumors, infiltration to the ventricular wall or previous surgery for the tumor. The average dose was 52.8 Gy to the tumor, 28.7 Gy to the whole brain and 21 Gy to the spinal axis. Five and ten-years survival rate were 100% and 96%, respectively. No intracranial recurrence or spinal metastasis has been found so far. Therefore no spinal irradiation seems to be unnecessary for non-high risk group of patients. Approximately 20 Gy should be sufficient, if spinal irradiation is to be indicated for high risk group. The dose for the primary tumor and whole brain could have been diminished to 40 Gy and 20 Gy, respectively.