The treatment outcome of 24 patients with pathologically-proven non-germinomatous
germ cell tumor was retrospectively investigated to determine the effectiveness of
radiotherapy. The patients were divided into three groups as follows: group 1, five patients with mature
teratoma with or without
germinoma; group 2, six patients with
immature teratoma with or without
germinoma; group 3, 13 patients with other highly malignant
tumors. The overall actuarial survival and relapse-free rates at 5 years were 82% and 59%, respectively, with a median follow-up period of 62 months. The actuarial relapse-free rate at 5 years was 100% for group 1, 63% for group 2 and 44% for group 3. There was no difference in the relapse-free rates between total resection and partial resection. Usage of
chemotherapy was adversely related to survival probably due to selection bias. No local failure was observed with 10 Gy or more for group 1,40 Gy or more for group 2 and 54 Gy or more for group 3. In groups 1 and 2, there was no spinal relapses without
craniospinal irradiation. In group 3, three of eight patients who did not receive
craniospinal irradiation and none of five patients who received
craniospinal irradiation experienced spinal relapse. In conclusion, highly malignant GCTs show a high incidence of spinal
metastasis and
craniospinal irradiation may reduce the risk of spinal
metastasis. Radiation dose and volume are to be determined according to the histopathological aggressiveness.