Impact of timing of radiation therapy on outcomes in atypical meningioma: A clinical audit.

BACKGROUND: The role of early adjuvant radiation therapy (RT) in patients with atypical meningioma remains controversial. The goal of this work was to report the impact of timing of RT on outcomes in atypical meningioma.

METHODS AND MATERIALS: Patients of atypical meningioma were identified through electronic search of institutional database. Following surgery, RT was delivered either in upfront adjuvant setting (early adjuvant RT) or after recurrence/progression (salvage RT).

RESULTS: There were 51 patients in the early adjuvant RT group and 30 patients in the salvage RT group. Six of 51 (12%) patients in the early adjuvant RT group recurred/progressed compared with 34 of 35 (97%) patients kept on observation after initial surgery. Thirty of these 34 patients received salvage RT, mostly after reexcision. Twelve of 30 (40%) patients recurred/progressed after salvage RT, compared with 6 of 51 (12%) patients after early adjuvant RT (P = .003). Post-RT 5-year progression-free survival was significantly better for early adjuvant RT compared to salvage RT (69% vs 28%, log-rank P < .001).

CONCLUSIONS: Within the limitations of any retrospective analysis, upfront early adjuvant RT can significantly reduce the risk of local recurrence/progression in atypical meningiomas compared with initial observation. A sizeable proportion of patients who are observed initially recur/progress over time necessitating salvage therapy; however, reexcision followed by salvage RT may not be as effective as early adjuvant RT.