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, Karnofski 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 7cm3 (2-35cm3), 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.