Laser thermal therapy: Real‐time MRI‐guided and computer‐controlled procedures for metastatic brain tumors

We report the final results of a pilot clinical trial exploring the safety and feasibility of real‐time magnetic resonance‐guided laser‐induced thermal therapy (MRgLITT) for treatment of resistant focal metastatic intracranial tumors.

In patients with chemotherapy, whole‐brain radiation, and radiosurgery resistant metastatic intracranial tumors, minimally invasive stereotaxic placement of a saline‐cooled interstitial fiberoptic laser applicator under local anesthesia was followed by laser irradiation during continuous magnetic resonance imaging (MRI) scanning. A computer workstation extracted real‐time temperature‐sensitive information for feedback control over laser delivery. A total of 15 metastatic tumors were treated in 7 patients. Patients were followed with physical exam and imaging for 30 months.

In all cases, the procedure was well tolerated, and patients were discharged home within 24 hours. Follow‐up imaging at up to 30 months showed an acute increase in apparent lesion volume followed by a gradual and steady decrease. No tumor recurrence within thermal ablation zones was noted. Kaplan–Meier analysis indicated that the median survival was 19.8 months.

Real‐time magnetic resonance (MR) guidance of laser‐induced thermal therapy (LITT) offers a high level of control. This tool therefore enables a minimally invasive option for destruction and treatment of resistant focal metastatic intracranial tumors. MR‐guided LITT appears to provide a safe and potentially effective treatment for recurrent focal metastatic brain disease. A larger phase II and III series would be of interest to quantify potential median survival advantage. Lasers Surg. Med. 43:943–950, 2011. © 2011 Wiley Periodicals, Inc.