J Neurol Surg B Skull Base 2017; 78(S 01): S1-S156
DOI: 10.1055/s-0037-1600557
Oral Presentations
Georg Thieme Verlag KG Stuttgart · New York

Overall Survival Benefit Associated with Adjuvant Radiotherapy in Who Grade II Meningioma

Chenyang Wang
1   Department of Radiation Oncology, University of California, Los Angeles, California, United States
,
Tania Kaprealian
1   Department of Radiation Oncology, University of California, Los Angeles, California, United States
,
John Suh
2   Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio, United States
,
Charlotte Kubicky
3   Department of Radiation Medicine, Oregon Health and Science University, Portland, Oregon, United States
,
Jeremy N. Ciporen
4   Department of Neurosurgery, Oregon Health and Science University, Portland, Oregon, United States
,
Yiyi Chen
5   School of Public Health, Oregon Health and Science University, Portland, Oregon, United States
,
Jerry J. Jaboin
3   Department of Radiation Medicine, Oregon Health and Science University, Portland, Oregon, United States
› Author Affiliations
Further Information

Publication History

Publication Date:
02 March 2017 (online)

 

Importance: Adjuvant radiotherapy (RT) after surgical resection of World Health Organization (WHO) grade II meningioma is a topic of controversy. Previous retrospective studies have arrived at conflicting conclusions on whether adjuvant RT reduces recurrence, and none observed an overall survival (OS) benefit associated with adjuvant RT.

Objective: To compare OS with or without adjuvant RT after subtotal resection (STR) or gross total resection (GTR) in patients with WHO grade II meningioma diagnosed according to the 2007 WHO classification.

Design, Setting, and Participants: The National Cancer Database (NCDB) was used to identify 2,515 patients who were diagnosed with WHO grade II meningioma between 2009 and 2012 and underwent STR or GTR with or without adjuvant RT.

Main Outcomes and Measures: Propensity score matching was first applied to balance covariates including age, year of diagnosis, sex, race, histology and tumor size in STR or GTR cohorts based on adjuvant RT status. Multivariate regression according to Cox proportional hazard model and Kaplan-Meier survival curves with log-rank test were then used to evaluate OS difference associated with adjuvant RT.

Results: More patients received adjuvant RT after STR than after GTR. GTR is associated with improved OS compared with STR. In the subgroup analysis, adjuvant RT in patients who underwent STR demonstrated significant association with improved OS compared with no adjuvant RT (adjusted hazard ratio [AHR] 0.590, p = 0.045), however adjuvant RT is not associated with improved OS in patients who underwent GTR (AHR 1.093, p = 0.737). In addition, dose-escalation to at or above the threshold dose of 54 Gy in 30 fractions in patients who underwent STR and adjuvant RT was not associated with improved OS (p = 0.970).

Conclusions and Relevance: Despite the lack of consensus on whether adjuvant RT reduces recurrence after surgical resection of WHO grade II meningioma, our study observed significantly improved OS with adjuvant RT compared with no adjuvant RT after STR of WHO grade II meningioma. This result is hypothesis generating, and it suggests that adjuvant RT after STR of WHO grade II meningioma may be associated with OS benefit.