Hypofractionated stereotactic reirradiation of recurrent glioblastomas. A beneficial treatment option after high-dose radiotherapy?

Recurrent malignant gliomas have a very poor prognosis. This trial aimed to evaluate the benefits of reirradiation in case of recurrent glioblastoma multiforme (GBM) using hypofractionated stereotactic radiotherapy (hFSRT) after primary high-dose percutaneous irradiation. Between 1998 and 2008, 53 patients with recurrent GBM were treated by hFSRT based on CT and MR imaging. At the time of recurrence, a median total dose of 30 Gy (20-60 Gy) was delivered in median fractions of 3 Gy/day (2-5Gy). The reirradiation was well tolerated (no acute or late toxicity > grade 2), despite the relatively large median tumor volume (35.01 ml). Karnofsky Performance Score was the strongest predictor for survival after reirradiation (p = 0.0159). Tumor volume (p = 0.4690), patient age (p 0.4301), second operation (p = 0.6930), and chemotherapy (p = 0.1466) at the time of reirradiation did not affect survival. After hFSRT, the median survival was 9 months, and the 1-year progression-free survival (PFS) amounted to 22%.The median overall survival from initial diagnosis was 27 months. 1-year survival from first diagnosis was 83%, 2-year survival 45%. The median time to progression from the end of initial irradiation to recurrence was 12 months. 1-year PFS before reirradiation was 40%. hFSRT as a secondary treatment of recurrent GBM is a feasible and effective treatment option. Only minor side effects were observed with prolonged life expectancy of 9 months. (orig.)