Management and outcomes of meningiomas secondary to childhood and adolescent radiation treatment

Background With the increased rate of childhood cancer survivors, a marked rise in the incidence of secondary intracranial meningiomas has been established. Objective Determine the outcomes of patients diagnosed with radiation-induced meningiomas (RIM). Methods Single-centre retrospective cohort study of patients with new or recurrent RIM (2007–2018). Results 47 patients were identified (21 females). Mean age at radiation was 15 years (SD=14) and the most common indications were leukaemia (n=8) and childhood brain tumours (n=35; medulloblastoma and pilocytic astrocytoma (n=7 each)). 93 de-novo meningiomas were identified. The median latency period between radiation and diagnosis was 28.5 years (IQR 22–37). 61% were asymptomatic whilst the remainder manifested headache (20%), focal neurological deficit (12%) and epilepsy (5%). 32 operated de-novo RIM revealed WHO grade I (n=19; 59%), WHO grade II (n=11; 34%) and 2 intraosseous meningiomas (n=2; 6%). After a median of 5 years (IQR 3–10), 9 (28%) operated RIM recurred/progressed. At recurrence, 5 were operated (3 WHO grade I, 2 WHO grade II and 1 WHO grade III), 2 patients were palliated and 2 remain under active observation. By the end of the study period, 20 patients were harbouring multiple meningiomas and 8 patients were deceased. Conclusion Radiation-induced meningioma should be monitored until symptomatic. Operated RIMs have a high recurrence rate. Further radiotherapy is not effective. Further clinical and genetic analyses as part of an international multi-centre collaboration are planned.