Increasing Seizure Activity during Radiation Treatment for High-grade Gliomas - Final Results of a Prospective Interventional Study

Background/Aim: Little is known regarding seizures during radiotherapy for brain tumors. This prospective study investigated seizure activity in patients irradiated for high-grade gliomas. Patients and Methods: Using a seizure diary, progression of seizure activity was evaluated in 22 patients receiving chemoradiation for grade III (n=1) or IV (n=21) gliomas. Progression was defined as increased frequency of any and/or generalized seizures (>50%) or increased anti-epileptic medication (≥25%). Patients’ satisfaction with the diary was assessed using a questionnaire (six scales of 1-7 points). Uni- and multivariable analyses were performed including baseline seizure activity, age, sex, resection, tumor site, performance score, and history of epilepsy/seizures. Results: Ten patients (45%) experienced progression of seizure activity during their radiotherapy course, mainly due to increased seizure frequency (nine patients=41%). Mean values of patients’ satisfaction scores ranged between 3.92 and 4.92 points. Conclusion: Radiotherapy of high-grade gliomas can increase seizure activity. Patients require close monitoring to initiate or adjust anti-epileptic medication.