Percutaneous microwave coagulation therapy for solitary metastatic liver tumors from colorectal cancer: A pilot clinical study

Objective: Percutaneous microwave coagulation therapy (PMCT) was performed for metachronous small solitary liver tumors measuring less than or equal t o 3.0 cm in diameter that had metastasized from colorectal cancer. PMCT was used for local control of the lesions, and the efficacy of this treatment was assessed. Methods: In 15 patients, a microwave electrode (specially des igned for this purpose, 25 cm long and 2.0 mm thick) was inserted percutane ously into the tumor area under ultrasonic guidance. Microwaves at 80 watts were used to irradiate the tumor and the surrounding area. Results: Thirte en of the 15 metastatic tumors were radically ablated by 3-10 applications of microwave irradiation. Although the follow-up period was short (9-37 mon ths), 10 patients survived. No recurrence has been detected in the treated area (except two foci where PMCT was insufficient), and no serious side eff ects or complications were encountered during or after the PMCT. In four of the five nonsurviving patients, death was due to metastases to the bone, b rain, lung, or other areas of the liver despite complete local tumor contro l by PMCT. Conclusion: PMCT is a safe and effective treatment for metachron ous small liver tumors that have metastasized from colorectal cancer. (Am J Gastroenterol 1999;94: 322-327. (C) 1999 by Am. Cell. of Gastroenterology) .