HYPOFRACTIONATED STEREOTAXIC RADIOTHERAPY IN THE MANAGEMENT OF RECURRENT GLIOMA

Purpose: This study aimed to assess the efficacy and toxicity of hypof ractionated stereotactic radiotherapy (SRT) in the management of patie nts with recurrent glioma. Methods and Materials: From January 1989 to July 1994, 36 patients with glioma were treated at the time of recurr ence. Twenty-nine had recurrent high-grade astrocytoma, 3 high-grade o ligodendroglioma, 1 high-grade ependymoma, and 3 pilocytic astrocytoma . Hypofractionated stereotactic radiotherapy was given using either th ree noncoplanar arcs or four to six noncoplanar fixed beams at 5 Gy/fr action, to doses ranging from 20 to 50 Gy initially on a dose escalati on program. Two patients received 20 Gy, 8 received 30 Gy, 10 received 35 Gy, 10 received 30 Gy, 5 received 35 Gy, and 1 received 50 Gy, tre ating 5 days/week. Results: The median survival of 29 patients with re current high-grade astrocytoma was 11 months from the time of SRT. Thi s compared to a median survival of 7 months for a cohort matched for a ge, performance status, and initial histologic grade who received nitr osourea-based chemotherapy at recurrence (p < 0.05). Initial low-grade astrocytoma histology was the only favorable prognostic factor for su rvival on univariate analysis. Three patients with recurrent oligodend roglioma remain alive 11, 23, and 34 months after SRT. Three children treated for recurrent pilocytic astrocytoma remain alive 14, 41, and 5 5 months following SRT. Presumed radiation damage, defined as reversib le steroid-dependent toxicity, was observed in 13 patients (36%) and r equired reoperation in 2 (6%). A total dose of >40 Gy was a major pred ictor of radiation damage (p < 0.005). Conclusion: Hypofractionated SR T is a noninvasive, well-tolerated, outpatient-based method of deliver ing palliative, high-dose, focal irradiation. (C) 1997 Elsevier Scienc e Inc.