Re-resection for Recurrent High-Grade Glioma in the Setting of Re-irradiation

Abstract

While patients with high grade gliomas (HGG) experience a high rate of recurrence, current treatment for recurrent lesions remains controversial. Many institutions offer surgical intervention, re-irradiation, systemic chemotherapy or biologic agents, or combination therapy. Historically, re-resection for recurrent GBM demonstrates a significant survival benefit following reoperation of 3-13 months compared to 1-2 months without treatment. Here we investigate whether re-resection will improve survival in patients receiving fractionated stereotactic radiation therapy (FSRT) for recurrence. Two hundred twenty-one patients with recurrent HGG treated with re-irradiation between 1994 and 2012 at our institution were analyzed. FSRT was delivered using daily fractions of 3.5 Gy, median total dose of 35 Gy. One hundred five patients also underwent re-resection. Survival was then analyzed comparing patients with and without re-resection. Median survival time (MST) was defined as survival from initial diagnosis. Patients still alive at the time of analysis were censored at the time of last follow-up. Survival analysis and factors that impact survival including age, extent of resection, and volume of the recurrent lesion were estimated using Kaplan-Meier plots. The MST from initial diagnosis of the entire group is 22.8 months. There is no significant difference in survival between patients who received re-resection vs no re-resection, the MST was 23 months, and 21.9 months respectively (p = 0.6). For patients who received re-resection, 97% had surgery first, followed by FSRT. The median time to surgery from initial diagnosis was 7.0 months. Median time to FSRT in those receiving re-resection was 9.1 vs 11.6 months in those without re-resection. Of the patients that underwent re-resection, 30 received gross total resection and 75 subtotal resection, with a MST of 22.0 and 26 months, respectively (p = 0.24). There is no significant difference in MST between patients older than 50 years vs younger, or large tumor volume (>50 cc) vs small (≤50 cc). Our data reveals there is no significant improvement in survival with the addition of re-resection to patients who received FSRT for recurrent HGG. To our knowledge, this data analyzes the largest cohort of patients with recurrent HGG treated with FSRT with and without surgical resection. We hypothesize that the favorable survival seen in our cohort is derived from local control benefit due to the addition of FSRT regardless of age, extent of resection and volume of recurrence.