Prognostic factors and outcome of atypical and anaplastic meningioma with and without radiation.

2083 Background: We evaluated outcome and prognostic factors for high grade meningioma (G2-3) and the role of early post-operative radiotherapy (RT). Methods: From 2000 to 2010, 136 patients were diagnosed with G2-3 meningioma at Northwestern: 124 with atypical (G2) and 12 with anaplastic (G3) meningioma. All were treated with or without RT after initial or subsequent resection. The primary endpoint was progression-free survival (PFS). Results: 21 patients received adjuvant RT, and 115 did not. Median PFS for G2 with and without RT was 68 vs.89 mos. Median PFS for G3 with and without RT was not reached=nr (mean 5) vs.60 mos (mean 35). Median PFS for Simpson G1-3 with and without RT was 18 vs.96 mos. Median PFS for Simpson G4 with and without RT was nr (mean 55) vs.59 mos (mean 44). For median follow-up of 33 mos for Simpson G1-3 and 29 mos for G4, recurrence rate for Simpson G1-3 with and without RT was 40 vs.6%, and for Simpson G4 with and without RT, 9 vs.31%. 3-yr OS for G2 with and without RT was 93 v...