Inclusion Criteria:  Age ≥ 18 years, non-pregnant, written informed consent The patient or caretaker is able to keep an epilepsy diary The patient has a diagnosis of epilepsy established by a dedicated Neurologist The patient had at least 3 focal-onset seizures with impairment of consciousness over a 3-month period despite two or more antiepileptic medication trials There is sufficient continuous video electroencephalography to determine a unilateral medial temporal seizure focus There is imaging evidence (i.e. MRI) of the anatomic region to be targeted correlating with the diagnosis of epilepsy The proposed anatomic region to be targeted aligns with anatomy associated with seizure reduction following focal treatment in literature A Wada test or a functional MRI to lateralize language has been performed The patient has completed a standard battery of neuropsychological testing There is absence of neurological or visual deficits outside of seizure episodes The patient been deemed an appropriate candidate for stereotactic radiosurgery by a dedicated Radiation Oncologist and Neurosurgeon Ability to give written informed consent  Exclusion Criteria:  Supratentorial abnormalities on brain MRI Neurological or visual deficits outside of seizure episodes History of psychiatric diagnoses Pregnancy