MRI tumor response and clinical outcomes after LINAC radiosurgery on 50 patients with recurrent malignant gliomas.

Background: The place of radiosurgery (RS) as an option in the treatment of recurrent malignant glioma is still debated on in the absence of prospective randomized trials. Objective: To assess the clinical outcome and MRI response after radiosurgery of recurrent malignant glioma. Methods: We evaluated 50 consecutive patients treated in a single institution. Between 2001 and 2008, 34 glioblastoma (GBM) and 16 anaplastic oligodendroglioma (AO) patients were treated with linear accelerator (Linac) RS for recurrence. Results: The median marginal dose was 15 Gy and the median gross tumor volume (GTV) was 6.64 ml. No patient had acute ( 70, marginal dose > 13 Gy, largest diameter of GTV < 25 mm and GTV < 7 ml were the main prognostic factors, associated with improved survival or PFS from RS. Conclusion: The magnitude of the survival increase compared to historical RPA classes may not be due to selection bias alone. Linac RS in selected patients with recurrent malignant glioma was well tolerated, effective and can be considered as one of several re-treatment options.