The role of adjuvant radiotherapy after gross total resection of atypical meningiomas

Background: Atypical meningiomas (AMs) frequently recur after gross total resection (GTR).

Objective: We conducted a meta-analysis to evaluate the benefit of adjuvant therapy after GTR of AMs.

Methods: A PubMed/MEDLINE search identified studies detailing AMs treated by GTR alone or GTR and adjuvant radiotherapy (RT) published between 1984 and 2012. Original data from 14 retrospective studies were combined and analyzed. Odds ratio (OR) and χ(2) testing were used when appropriate. Selected datasets were used to generate each variable, where available.

Results: A total of 757 patients (male/female ratio 9:10) with AMs were included; 72.52% (n = 549) of AMs were treated by GTR alone, and 27.47% (n = 208) underwent adjuvant RT after GTR to a median dose of 54 Gy. The crude recurrence rate was twice as high without adjuvant RT (33.7% vs. 15%, P = 0.005). The 1-year local control rate was 90% for GTR and 97% for GTR + RT (OR = 3.36, P = 0.11). The median 5-year local control rate was 62% for GTR and 73% for GTR + RT, respectively (OR = 1.71, P = 0.06). The 5-year overall survival for each group was 90% (OR = 0.97, P = 0.95). A total of 85% of recurrences were salvaged, 33% by RT and 67% by surgery. Radiation-related toxicity was <10%, at a median follow-up of 42 months.

Conclusions: Postoperative RT for AMs may decrease risk for relapse of disease and improve local control, although most tumors are salvageable with surgery or radiation. Although the data suggest little or no impact of postoperative RT on survival, further investigation regarding the long-term efficacy and toxicity of radiation is warranted.