Evidence on the efficacy of primary radiosurgery or stereotactic radiotherapy for drug-resistant non-neoplastic focal epilepsy in adults: A systematic review

Seizure. 2018 Feb;55:83-92. doi: 10.1016/j.seizure.2018.01.009. Epub 2018 Jan 31.


Purpose: Although the majority of adult epilepsy patients respond well to the current antiepileptic drug treatment, 20-40% of them are drug-resistant. In these patients, resective epilepsy surgery is a curative treatment option, for which, however, only a limited number of patients is eligible. The purpose is to summarize the outcome of radiotherapy for drug-resistant non-neoplastic focal epilepsy and to elucidate its efficacy for seizure outcome and long-term toxicity in adults.

Method: A systematic literature search was performed in Pubmed, Ovid Medline, Cochrane library, Embase and Web of Science. The methodological quality was evaluated using an adapted QUADAS checklist.

Results: Sixteen out of 170 initially identified studies were included in this systematic literature study (n = 170 patients). Twelve of the 16 studies described a positive effect of radiotherapy on seizure frequency reduction, with 98 of the patients (on average 58%, range 25%-95%) reporting no or rare seizures (defined as radiotherapy-adapted Engel class [RAEC] I and II. In total, 20% (34 patients) of the patients needed subsequent surgery due to radionecrosis, cysts formation, edema, and intracranial hypertension or remaining seizures. A dose-effect model was fitted to the available response data in an attempt to derive a relationship between prescribed dose and RAEC frequency.

Conclusions: Radiotherapy is a possible non-invasive treatment option for patients with drug-resistant focal non-neoplastic epilepsy. This systematic review showed that there is only level 4 evidence of primary radiotherapy reducing seizure frequency in adult patients. Prospective randomized trials are needed to determine its exact value compared to other treatment approaches.

Keywords: Epileptogenic lesions; Focal epilepsy; Radiosurgery; Stereotactic radiotherapy.

Publication types

  • Review
  • Systematic Review

MeSH terms

  • Adult
  • Drug Resistant Epilepsy / surgery*
  • Epilepsies, Partial / surgery*
  • Humans
  • Radiosurgery*
  • Treatment Outcome