Epilepsy in Patients with Cerebral Radiation Necrosis: A Scoping Review

Background and Objectives: Cerebral radiation necrosis (CRN) is a delayed complication of radiation therapy (RT), that can appear either as radiological findings without clinical symptoms (i.e., asymptomatic CRN) or symptomatic CRN (sCRN). There is currently a knowledge gap regarding CRN-induced epilepsy, a potentially severe manifestation of sCRN. We aim to give a comprehensive overview of the existing literature on CRN-induced epilepsy, including its prevalence, potential risk factors, and treatment options. Materials and Methods: A scoping analysis was performed according to the PRISMA scoping review guidelines. We searched within PubMed and Embase databases and identified relevant clinical studies for inclusion related to CRN-induced epilepsy, based on predefined criteria. Results: In total, 24 studies were identified. CRN-induced epilepsy was a primary outcome in three studies. In the 21 remaining studies, epilepsy was an exploratory outcome or described as part of a small case series. The studies covered various topics in relation to CRN-induced epilepsy, such as the overall clinical manifestations of CRN, the optimization of RT practices to minimize toxicity and improve outcomes, and the effectiveness of laser interstitial thermal therapy (LITT) and bevacizumab. Considerable heterogeneity was seen across studies, particularly concerning the primary tumor types, used definition of CRN and applied RT practices. Conclusions: Epilepsy is a serious clinical symptom in patients with sCRN. However, the current literature is too limited to draw meaningful conclusions regarding its prevalence, risk factors and management. Future research in patients with sCRN should prioritize the evaluation of clinical response to different treatment strategies with particular attention to seizure control.