HEPATIC METASTASES - INTERSTITIAL LASER PHOTOCOAGULATION WITH REAL-TIME US MONITORING AND DYNAMIC CT EVALUATION OF TREATMENT

Fifty-five liver metastases in 21 patients were treated with interstit ial laser photocoagulation (ILP). Tumors were irradiated with a neodym ium yttrium aluminum garnet laser via optical fibers passed through 19 -gauge needles inserted under ultrasound (US) guidance. Heating of the tumor was evident at real-time US as an expanding and coalescing echo genic zone around the needle tips. After ILP, dynamic computed tomogra phy (CT) showed laser-induced necrosis as a new area of nonenhancement Necrosis of tumor volume was more than 50% in 82% (45 of 55) of the t umors, and 100% necrosis was achieved in 38% (21 of 55). Metastases sm aller than 4 cm in diameter were treated more effectively and required fewer treatment sessions than did those larger than 4 cm. Complicatio ns were minor and included severe pain in four cases, persistent pain for up to 10 days in 11 cases, and asymptomatic subcapsular hematoma ( four cases) and pleural effusion (six cases) seen with CT. ILP is safe and effective for fiver tumor destruction, and US and CT are useful i n different aspects of treatment monitoring.