EPID-14. EPIDEMIOLOGICAL SURVEY OF RADIATION-INDUCED MENINGIOMA: A SEER ANALYSIS

Abstract

Abstract OBJECTIVE Radiation-induced meningioma (RIM) is a rare but serious consequence of cranial and cranio-spinal external beam radiation therapy (EBRT). While recent studies have characterized the epidemiological features of RIM in small populations or systematic reviews, none have studied RIM within a national database for a more generalizable description of this disease entity. The objective of this study was to identify and characterize the population with RIMs within a large national database. METHODS From the SEER Research Plus Nov 2020 (1975-2018) dataset, 56161 patients treated with EBRT for the following indications were identified: ocular/orbital tumors, brain/nervous system tumors, and leukemias. Next, a sub-population of 185 RIM patients, defined by histologically distinct precedent tumor treated with EBRT and a minimum 5-year latency from EBRT to meningioma, was identified. RIM prevalence, latency, pathologic behavior, and multiplicity were determined, and comparisons were made by sex, race, and original indication for EBRT. RESULTS The prevalence of RIM among the EBRT population was 0.33%. Among RIM patients, 41.62% were male and 84.32% were Caucasian. Average latency to RIM development was 23.39 ± 8.65 years, with no significant difference between sexes or races. Fourteen patients had multiple RIMs at diagnosis, while four patients experienced recurrent RIM. RIMs classified as “malignant” had a shorter latency (16.30 years) than “borderline” (26.11 years) or “benign” (23.36 years) RIMs. Of the most common original EBRT indications, precursor lymphoblastic leukemia (29.89 years) had longer latency to RIM than medulloblastoma (21.57 years) or astrocytoma (22.67 years); this may be explained by lower doses of radiation used for lymphoblastic leukemia treatment. CONCLUSION These data provide novel epidemiological information—most importantly, prevalence—of RIM in a nationwide population, and they suggest that RIM occurs in patients independent of sex or race. These findings will aid clinicians in explaining the risk of RIM development to patients undergoing EBRT.