Magnetic Resonance Thermometry-Guided Stereotactic Laser Ablation of Cavernous Malformations in Drug-Resistant Epilepsy: Imaging and Clinical Results

• Authors: D. Jay McCracken, Emory University; Jon Willie, Emory University; Brad Fernald, Visualase Inc; Amit Saindane, Emory University; Daniel Drane, Emory University; Daniel Barrow, Emory University; Robert Gross, Emory University
• Journal Title: Operative Neurosurgery
• Volume: Volume 12, Number 1
• Publisher: Lippincott, Williams & Wilkins | 2016-03-01, Pages 39-48
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1227/NEU.0000000000001033
• Subjects: Health Sciences, Medicine and Surgery; Health Sciences, Radiology
• Keywords: Science & Technology; Life Sciences & Biomedicine; Clinical Neurology; Surgery; Neurosciences & Neurology; Cavernous malformation; Epilepsy; Laser therapy; Magnetic resonance imaging; Minimally invasive surgical procedures; Stereotactic techniques; Thermometry; TEMPORAL-LOBE EPILEPSY; INDUCED INTERSTITIAL THERMOTHERAPY; GAMMA-KNIFE RADIOSURGERY; METASTATIC BRAIN-TUMORS; INDUCED THERMAL THERAPY; RECURRENT GLIOBLASTOMAS; MR; RESECTION; HEMANGIOMAS; ANGIOMAS

Abstract

BACKGROUND:: Surgery is indicated for cerebral cavernous malformations (CCMs) that cause medically refractory epilepsy. Real-time magnetic resonance thermography (MRT)-guided stereotactic laser ablation (SLA) is a minimally invasive approach to treating focal brain lesions. SLA of CCM has not previously been described. OBJECTIVE:: To describe MRT-guided SLA, a novel approach to treating CCM-related epilepsy, with respect to feasibility, safety, imaging, and seizure control in 5 consecutive patients. METHODS:: Five patients with medically refractory epilepsy undergoing standard presurgical evaluation were found to have corresponding lesions fulfilling imaging characteristics of CCM and were prospectively enrolled. Each underwent stereotactic placement of a saline-cooled cannula containing an optical fiber to deliver 980-nm diode laser energy via twist drill craniostomy. MR anatomic imaging was used to evaluate targeting before ablation. MR imaging provided evaluation of targeting and near real-time feedback regarding the extent of tissue thermocoagulation. Patients maintained seizure diaries, and remote imaging (6-21 months postablation) was obtained in all patients. RESULTS:: Imaging revealed no evidence of acute hemorrhage following fiber placement within presumed CCM. MRT during treatment and immediate postprocedure imaging confirmed the desired extent of ablation. We identified no adverse events or neurological deficits. Four of 5 (80%) patients achieved freedom from disabling seizures after SLA alone (Engel class 1 outcome), with follow-up ranging 12 to 28 months. Reimaging of all subjects (6-21 months) indicated lesion diminution with surrounding liquefactive necrosis, consistent with the surgical goal of extended lesionotomy. CONCLUSION:: Minimally invasive MRT-guided SLA of epileptogenic CCM is a potentially safe and effective alternative to open resection. Additional experience and longer follow-up are needed. ABBREVIATIONS:: CCM, cerebral cavernous malformationsGRE, gradient recalled echoMRT, magnetic resonance thermographySLA, stereotactic laser ablation