In vivo laser‐induced interstitial thermotherapy of pig liver with a temperature‐controlled diode laser and MRI correlation

Abstract

BACKGROUND AND OBJECTIVE: To evaluate the efficacy of a new temperature-controlled Diode laser to generate in vivo tissue coagulations with laser-induced interstitial thermotherapy (LITT) in pig liver and MRI-correlation of these necroses. STUDY DESIGN/MATERIALS AND METHODS: Each of four animal subjects received eight treatments at four different constant temperatures (70, 80, 90, and 100 degrees C) and at two out of three different intervals (3, 6, 9 minutes), resulting in a total of 32 lesions. After sacrificing, the liver was examined in an open MRI (0.35T). Tissue necrosis was measured macroscopically and compared with the size measured by MRI. RESULTS: The size of the necrosis was energy dependent with the largest extent at 100 degrees C at 9 minutes (2.1 cm). The correlation between macroscopic lesion size and MRI findings was significant (P > 0.036). Histological workup excluded carbonization in every case. CONCLUSIONS: LITT carried out with the Diode laser provides reproducible necroses of pig liver in vivo. MR-imaging results compared favorably with those obtained by pathologic specimens.