In this PRECISION-study including adult patients with drug-resistant, localised epilepsy, not eligible for surgery, we offer non-invasive linear accelerator (LINAC) based Stereotactic Radiotherapy (SRT) with curative intent.~SRT and stereotactic radio-surgery (SRS) have been used to treat several types of neoplasms in the brain for several decades. Several publications (level 2 evidence) have shown the potential value of SRT in patients with drug-resistant epilepsy, however no level-1 evidence was given enabling guideline development. A recent systematic review from our institution has shown that SRT resulted in a significant seizure cure or reduction in 58% of the 170 included patients, within 2 years after treatment. Interestingly, the ROSE trial, randomising between open surgery and SRT, has demonstrated a seizure remission of 52% in the radiotherapy group after 2 years with the proportion of seizure-free patients still increasing with a longer follow-up up to 74% after 3 years. Therefore, SRT may be considered a curative treatment for drug resistant localised epilepsy. Currently, randomized controlled SRT epilepsy trials are lacking and there is a need for high quality evidence, so SRT can be clinically implemented for localised drug-resistant epilepsy patients in the Netherlands as well.~In the PRECISION-study, patients will be randomised in a 1:1 ratio between SRT and current standard care, where the latter includes AEDs and neuromodulation (i.e. DBS or VNS and/or AED continuation). We hypothesize that SRT alters the epileptogenic cerebral tissue to yield a reduction in seizures and possibly cure after 2 years, with a significant increase in the patients' quality of life.
The PRECISION-study offers a non-invasive, curative intervention for drug-resistant localised epilepsy patients who are not eligible for surgery. The intervention will consist of a single LINAC based SRT treatment and is given by the radiation-oncologist after detailed localisation of the epileptogenic zone with the neurologist, radiologist and neurosurgeon. This intervention will make curative-intent treatment possible where this could otherwise not be given and is a non-invasive and non-competitive alternative to epilepsy surgery. It is expected that the health costs for this curative treatment will not exceed standard treatment, such as lifelong medication and neuromodulation.