Outcomes of WHO Grade I Meningiomas Receiving Definitive or Postoperative Radiotherapy

Abstract

We analyzed long-term local control and complications in patients with either pathologically confirmed or clinical World Health Organization Grade I meningiomas treated with definitive or postoperative radiotherapy (RT) at the University of Florida. Between 1984 and 2006, 146 patients were treated with definitive (n = 88) or postoperative RT after subtotal resection (n = 57) or gross total resection (n = 1). Patients were treated with conventional (n = 41), stereotactic (n = 103), or intensity-modulated RT (n = 2) to a median dose of 52.7 Gy and followed for a median of 7.3 years (range, 0.6-22.0 years) The local control rates at 5 and 10 years were as follows: definitive RT, 99% and 99%; postoperative RT, 96% and 93%; and overall, 97% and 96%, respectively. The 5- and 10-year cause-specific survival rates were as follows: definitive RT 94% and 94%, postoperative RT, 100% and 96%; and overall, 96% and 95%, respectively. The 5- and 10-year overall survival rates were as follows: definitive RT, 81% and 75%; postoperative RT, 96% and 85%; and overall, 87% and 79%, respectively. Severe RT complications occurred in 6.8% of patients; severe surgery-related complications occurred in 10 (17%) of 58 patients treated surgically. The likelihood of cure after definitive RT or following subtotal resection is excellent. However, a small population of patients experience severe complications, even at the moderate dose used for this disease.