Image-guided LINAC radiosurgery in hypothalamic hamartomas.

Abstract Purpose. Hypothalamic hamartomas (HH) are benign brain tumors that are associated with mild to severe drug-refractory epilepsy. Stereotactic radiosurgery (SRS) is an emerging non-invasive option for the treatment of small and medium-sized HH, providing excellent seizure outcomes without neurological complications. Here, we report our experience treating HH with LINAC image-guided SRS.Methods. We retrospectively collected clinical and neuroradiological data of ten subjects with HH-related epilepsy that underwent frameless image-guided SRS.Results. All patients underwent single-fraction SRS using a mean prescribed dose of 16.27 Gy. The median prescription isodose was 79%. The mean target volume was 0.64 cc. Eight patients experienced complete or near complete seizure freedom (Engel class I and II). Five patients achieved complete seizure control within 4 to 18 months after the treatment. Four patients achieved Engel class II outcome, with stable results. One patient had a reduction of seizure burden superior to 50% (Engel class III). One patient had no benefit at all (Engel class IV) and refused further treatments. Overall, at the last follow-up, three patients experience class I, five class II, one class III and one class IV outcome. Six patients experienced major neuropsychological improvement. No neurological complications were reported.Conclusions. Image-guided frameless LINAC SRS provides excellent seizure and long-term neuropsychosocial outcome, without the risks of neurological complications inherently associated with microsurgical resection.