P27.02.A ANTI-EPILEPTIC WITHDRAWAL IN GLIOMAS: A RETROSPECTIVE STUDY IN A SINGLE SCOTTISH TERTIARY CENTRE Free

Seizures are common in brain tumours (BTs). With no fixed guidelines to guide anti-epileptics (AEDs) discontinuation in BTs, we evaluated factors influencing the decision to discontinue AEDs and its outcome.

Retrospective study on single regional centre for neuro-oncological service from April 2018 to April 2023. Eligible BT patients were seizure free ≥ 1 year post surgery, had histologically confirmed gliomas (WHO grade I-IV) and underwent gross total resection. We analysed separately patients who were weaned after being started on AEDs prophylactically. Primary outcomes were: (1) shared decision-making outcome and (2) seizure recurrence. Data analysed included tumour characteristics, antitumour treatments and seizure freedom.

Over 2020-2023, 30/240 patients (13%) met the selection criteria for AED withdrawal and 22/30 (73%) were agreeable to AEDs withdrawal. 9/22 (41%) of those who withdrew AEDs had seizure recurrence, with 6/9 (67%) having a seizure within 6 months following withdrawal. 5/9 (55%) had tumour progression within 3-6 months of having a seizure. None of those who remained on AEDs had seizure recurrence.A shorter BT related epilepsy (BTRE) duration (p<0.01) and radiotherapy treatment (p<0.05) resulted in decreased seizure recurrence following withdrawal. Most patients were on Levetiracetam monotherapy and our data did not allow comparison with other AEDs.

In 73% of patients, a shared decision process led to AEDs withdrawal, with 59% remaining seizure free. Lower recurrence risk was linked to shorter BTRE duration and radiotherapy. Further studies are required to better stratify patients at higher risk of seizure recurrence.