ULTRASOUND MONITORED LASER-INDUCED LOCAL HYPERTHERMIA IN THE LIVER - AN EXPERIMENTAL-STUDY ON PIGS

Ultrasound (US) was used to monitor the size of tissue necrosis genera ted by Nd-YAG laser-induced local interstitial hyperthermia and tissue coagulation in 8 normal pig livers. Four treatments were done in each liver with 4 different energy settings. The size of the tissue necros is measured on specimens was compared to the size measured on US. The laser energy caused a round tissue necrosis with some charring in the centre surrounded by a zone of white necrosis and a thin border of hyp eraemia. A good correlation was found between the true and US-measured size of the necrosis diameters. It therefore seems possible to safely guide and monitor local laser hyperthermia in the liver with real-tim e US. The water-cooled quartz fibre used in this study has, however, s ome limitations.