[Radiation-induced fibrosarcomas rapidly appeared more than 20 years after radiation therapy for germ cell tumors: report of two cases].

: Radiation-induced brain tumor is a rare but serious and potentially fatal complication. We report two cases of radiation-induced fibrosarcomas which occurred more than 20 years after whole brain radiation therapy (60 Gy) for intracranial germinomas. Although both of them underwent imaging examination every year, the symptomatic sarcomas developed rapidly within a year. Eight months after total removal, the tumor recurred in the one case. Second surgery and gamma knife surgery could not prevent the tumor progression. In the other case, tumor regrowth was not observed during the five months follow-up after total removal surgery. It is important to keep in mind the possibility of a postradiation sarcoma that might have developed very aggressively after a long latent period.