Laser-induced interstitial induced hyperthermia of cerebral tumors with nuclear magnetic resonance tomography control

Abstract

The purpose of our study was to determine the value of MRI in monitoring laser-induced interstitial thermotherapy (LITT) of cerebral neoplasms. Sixteen patients with brain tumors were treated with LITT. The laser irradiation was performed within the MR unit and monitored with a temperature-sensitive T1-weighted 2D-FLASH sequence. During irradiation a gradually increasing central zone of high signal intensity was surrounded by an increasing area of reduced signal intensity. After therapy, the diameter of an enhancing rim at the outer border of the peripheral zone indicated total lesion size. On T2-weighted images the signal intensities were reversed. Total lesion size decreased during follow-up. MRI is suitable for monitoring LITT. However, the role of LITT in the treatment of brain tumors has still to be defined.