Possible radiation-induced dural fibrosarcoma with an unusually short latent period: case report.

We report a case of radiation-induced dural fibrosarcoma in a 9.5-year-old male patient who was treated with radiation for medulloblastoma. He received a total dose of 53.2-Gy radiation, delivered at 1.6 and 1.8 Gy per fraction with a 6 MV linear accelerator using the standard cranial-spinal technique. A sequential magnetic resonance image at 15 months after the completion of radiation therapy showed a mass above the cerebral convexity that increased two-fold in size within a period of 4 months. The tumor showed characteristics of a low-grade fibrosarcoma. This case emphasizes the potential risk of early development of a second neoplasm after therapeutic radiation, especially in children, and also documents what is to our knowledge the shortest latent period between the administration of radiation therapy and the development of an intracranial fibrosarcoma that has been reported.