CyberKnife® Radiosurgery as First-line Treatment for Catastrophic Epilepsy Caused by Hypothalamic Hamartoma

Abstract

Hypothalamic hamartomas (HH) are deep-seated lesions often associated with catastrophic epilepsy (an epileptic syndrome characterized by severe, drug-refractory seizures eventually leading to mental retardation and death). Radical microsurgical resection is not feasible for lesions located within the wall of the third ventricle inside the hypothalamus. Frame-based stereotactic radiosurgery has been reported as an effective treatment modality for small- to medium-size intrahypothalamic hamartomas, providing excellent seizure outcomes without lasting complications. This report describes the use of frameless image-guided robotic radiosurgery (CyberKnife® Radiosurgery System) as a first-line treatment in two children with catastrophic epilepsy induced by HH. Both patients experienced multiple-daily complex partial and gelastic seizures, as well as almost daily generalized seizures. The prescribed dose was 16 Gy (to the 65% isodose for case I; to the 70% isodose for case II). Lesional volume was 11.5 cc (case I) and 8.9 cc (case II). A steady reduction of the seizure frequency and severity was achieved after the treatment, starting about three months after the treatment. The generalized seizures disappeared within one year, while complete resolution of the gelastic seizures required up to 18 months. No seizure recurrence and no radiation-induced side effects or complications were witnessed over a follow-up period of ten years and eight months (case I) and nine years and seven months (case II) since the treatment. CyberKnife radiosurgery proved to be a safe and effective non-invasive first-line treatment in these two children with catastrophic epilepsy caused by HH.

Applications of Frameless Image-Guided Robotic Stereotactic Radiotherapy and Radiosurgery in Pediatric Neuro-Oncology: A Systematic Review

“…The case reports summarized herein are comparable in terms of tumor entities, indication, and dosimetric parameters to the larger reports of Mohamad et al and Giller et al, reporting on very specific, individual treatments [ 20 , 21 ]. For example, Romanelli reported two cases of pediatric patients suffering from unresectable hypothalamic hamartomas causing severe, daily gelastic, and generalized tonic-clonic seizures [ 22 ]. Despite intensive usage of up to five antiepileptic drugs, seizure control remained poor [ 22 ].…”

“…For example, Romanelli reported two cases of pediatric patients suffering from unresectable hypothalamic hamartomas causing severe, daily gelastic, and generalized tonic-clonic seizures [ 22 ]. Despite intensive usage of up to five antiepileptic drugs, seizure control remained poor [ 22 ]. In an attempt to reduce seizure frequency and severity, the eight- and nine-year-old children underwent single-session RRS.…”

“…In an attempt to reduce seizure frequency and severity, the eight- and nine-year-old children underwent single-session RRS. Eighteen and 36 months after treatment, respectively, both patients started to remain seizure-free for the available follow-up of 10 and 9 years [ 22 ]. Discontinuation of antiepileptic medication started two and three years after RRS, respectively [ 22 ].…”

“…Eighteen and 36 months after treatment, respectively, both patients started to remain seizure-free for the available follow-up of 10 and 9 years [ 22 ]. Discontinuation of antiepileptic medication started two and three years after RRS, respectively [ 22 ]. No treatment-related toxicity was observed.…”

One-Stage High-Density Focal Stereo-Array SEEG-Guided Radiofrequency Thermocoagulation for the Treatment of Pediatric Giant Hypothalamic Hamartomas

“…Additionally, craniotomy was typically associated with incomplete resection ( 28 ) and multiple complications, including DI, appetite stimulation, and severe surgery-induced injuries ( 14 ). Gamma knife surgery (GKS) is often used as well ( 29 , 30 ). The disadvantages of radiosurgery are its delayed action ( 31 ); moreover, large or giant HHs are not appropriate for GKS ( 30 , 32 ).…”