Stereotactic radiosurgery (SRS)

BACKGROUND: This article describes the results of a study of stereotactic radiosurgery (SRS) in the treatment of patients with recurrent malignant glioma. METHODS: Thirty-two patients with recurrent glioblastoma multiforme (GBM) were treated for 36 lesions with SRS from 1993 to 2001. Nineteen patients were male and 13 were female. The median age at primary diagnosis of the tumor was 56 years (range, 33-76 yrs). At the time of initial diagnosis a total neurosurgical resection was performed in 7, a subtotal resection in 21, and a biopsy in 4 patients. Histology evaluations revealed glioblastoma multiforme (WHO Grade IV) in all 32 patients. In all patients radiotherapy was performed as the first-line therapy, applied as fractionated external beam radiotherapy. The median interval between primary irradiation and reirradiation was 10 months. The median dose applied was 15 Gy (range, 10-20 Gy) prescribed to the 80% isodose line that encompassed the target volume. No concomitant chemotherapy was applied. RESULTS: Treatment was well tolerated by all patients. No acute toxicities > CTC Grade II occurred. No severe long-term toxicities including radionecrosis were observed. The median follow-up time was 13 months (range, 1-89 mo). All patients died of tumor progression during follow-up. The median overall survival from primary diagnosis of the tumor was 22 months (range, 9-133 mo). The survival rate at 1 year was 90%, and 49% and 26% at 2 and 3 years, respectively. Median overall survival after SRS was 10 months. At 6 and 12 months after SRS, survival rates were 72% and 28%, respectively. Median progression-free survival after SRS was 7 months. CONCLUSIONS: SRS offers effective treatment as a salvage therapy for a subgroup of patients with smaller lesions of recurrent GBM.