NT-30 * COMPLICATIONS OF LASER INTERSTITIAL THERMAL THERAPY IN PATIENTS WITH BRAIN TUMORS

Abstract

OBJECTIVE: Laser interstitial thermal therapy (LITT) has been described as a treatment for patients with brain tumors refractory to other treatments, with little emphasis on the risks of the procedure. This report focuses on complications of LITT in patients with tumors of the central nervous system. METHODS: Laser probes were inserted in the operating room using low-field intraoperative MRI (iMRI) guidance (5 patients), frameless stereotaxy (FS) in 2, and frame-based placement in 3. LITT itself was done in a 1.5 Tesla diagnostic MRI. Diagnoses included metastatic tumors in 7 patients, glioma in 2, and pituitary tumor in 1. One patient had a filum terminale ependymoma (with laser placement in the diagnostic MRI). RESULTS: In 1 patient in whom FS was used for image guidance, diagnostic MRI showed the laser fiber to be misplaced. Three complications resulted from the LITT itself. One patient with a glioblastoma of the vermis and fourth ventricle had bilateral palsies of cranial nerves 6 and 7 after treatment. A patient with a recurrent metastatic tumor after stereotactic radiosurgery had worsened left hemiparesis. These two patients were treated with steroids, with partial improvement of their deficits. The patient with the filum terminale ependymoma developed a paraparesis the day after treatment; MRI showed expansion of the intraspinal mass with resolution of enhancement, consistent with tumor ablation. She required a laminectomy and removal of the mass, with a combination of tumor and necrosis on histological examination. CONCLUSIONS: Complications of LITT can result from laser misplacement and from the laser treatment itself. Use of a stereotactic frame can limit the risk of inaccurate placement. Avoiding complications of the LITT itself can be done by undertreating the margin of a target in close proximity to critical structures. Intraspinal LITT should be used with great caution.