Radiation-Induced Meningiomas After Childhood Brain Tumor: A Magnetic Resonance Imaging Screening Study

Childhood brain tumors (CBTs) and their treatment increase the risk of secondary neoplasms (SNs). We studied the incidence of secondary craniospinal tumors with magnetic resonance imaging (MRI) screening in a national cohort of survivors of CBT treated with radiotherapy, and we analyzed the Finnish Cancer Registry (FCR) data on SNs in survivors of CBT with radiotherapy registered as a part of the primary tumor treatment. A total of 73 survivors of CBT participated in the MRI study (mean follow-up of 19 ± 6.2 years). The incidence of SNs in a cohort of CBT patients (N = 569) was retrieved from the FCR (mean follow-up of 11 ± 12.9 years). Brain tumors were diagnosed at age ≤16 years between the years 1970 and 2008 in the clinical study and the years 1963 and 2010 in the FCR population. Secondary brain tumors, meningiomas in all and schwannoma in one, were found in 6 of the 73 (8.2%) survivors with a mean of 23 ± 4.3 years after the diagnosis of the primary tumor. The cumulative incidence was 10.2% (95% confidence interval [CI] 3.9-25.1) in 25 years of follow-up. In the FCR data, the 25-year cumulative incidence of SNs was 2.4% (95% CI 1.3-4.1); only two brain tumors, no meningiomas, were registered. Survivors of CBT treated with radiotherapy have a high incidence of meningiomas, which are rarely registered in the FCR.