Background and purpose: To compare the outcome from adjuvant and delayed radiotherapy (RT) after surgery in patients with benign cerebral meningioma.
Patients and methods: Between March 1953 and January 2001, 92 patients with benign cerebral meningioma (WHO grade I) were treated with surgery. Forty-eight patients underwent gross total resection (GTR), and 44 patients underwent subtotal resection (STR). Treatments were classified as GTR (n = 48), STR+adjuvant RT (n = 12), STR alone (n = 32). The prognostic factors were assessed as, gender, the Karnofsky performance score (KPS) (> or =90 vs. <90), the extent of surgery, and adjuvant or delayed RT. The endpoints analyzed were progression-free survival (PFS) and overall survival (OS). Overall survival curve of the study population is compared with the age-adjusted expected survival curve for the US population born in 1970.
Results: The median follow-up was 7.7 years. The 5-year PFS and OS rates for all patients were 65 and 93%, respectively. The 5-year PFS rates in patients treated with GTR and STR were 77 and 52%, respectively (P = 0.02). Patients treated with STR+adjuvant RT had significantly better PFS (91%) at 5 years than with STR alone (38%) (P = 0.0005). Gender showed no statistically significant impact on either PFS or OS (P > 0.05). However, multivariate analysis showed the KPS to have a statistically significant effect on OS (P = 0.02). The OS rate was the same across all three treatment groups. The age-adjusted expected survival curve for the US population born in 1970 lay within the confidence intervals for the overall survival curve of the study population.
Conclusions: Although OS was not affected, adjuvant RT appeared to significantly reduce tumor progression. However, only a prospective randomized trial can adequately determine whether adjuvant or delayed radiotherapy is the better approach in patients with subtotally resected benign meningioma.