Results of salvage stereotactic radiosurgery in 14 patients with grade III or IV gliomas

Aims. To determine local control and overall survival rates of 14 patients treated for a grade III or IV glioma relapsing in a previously irradiated area and re-irradiated by stereotactic radiosurgery. Patients and methods. From January 1997 to October 2001, 14 patients (median age 52 years, age range 49-58 years, Kamofski performance score 80 to 100) received radiosurgery for a relapse of grade III (3 patients) and or grade IV (10 patients) malignant gliomas. Before relapse, all patients had undergone surgery and had been given with a classical radiation protocol. Median maximum diameter and volume of the tumors were 38.5mm (24-86mm) and 7cm(3) (2-35cm(3)), respectively. Results. Median maximal dose at the isocenter and median minimal dose at the periphery of the lesion were 21Gy (16-38Gy) and 13Gy (9-17Gy), respectively. Mean follow-up was 8.5 months (1-29). Median overall survival was 11.6 months; 6-month, 1- and 2-year overall survival rates were 85p. 100, 36p. 100 and 12p. 100, respectively. At univariate analysis, only histological grade was a significant prognostic factor of overall survival (p = 0.03). Median disease-free survival was 8.2 months while 6-month and 1-year disease-free survival rates were 69p. 100 and 14p. 100, respectively. According to univariate analysis, histological grade (p = 0.033) and minimal dose delivered at the margin of the target volume (p = 0.02) were prognostic factors for disease-free survival. Two patients developed a symptomatic radionecrosis. Conclusion. Radiosurgery of relapsed primitive high-grade brain tumors is efficient and overall survival rates were encouraging.