Objective: Percutaneous microwave coagulation therapy (PMCT) was performed for metachronous small solitary liver tumors measuring < or = 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 designed for this purpose, 25 cm long and 2.0 mm thick) was inserted percutaneously into the tumor area under ultrasonic guidance. Microwaves at 80 watts were used to irradiate the tumor and the surrounding area.
Results: Thirteen of the 15 metastatic tumors were radically ablated by 3-10 applications of microwave irradiation. Although the follow-up period was short (9-37 months), 10 patients survived. No recurrence has been detected in the treated area (except two foci where PMCT was insufficient), and no serious side effects or complications were encountered during or after the PMCT. In four of the five nonsurviving patients, death was due to metastases to the bone, brain, lung, or other areas of the liver despite complete local tumor control by PMCT.
Conclusion: PMCT is a safe and effective treatment for metachronous small liver tumors that have metastasized from colorectal cancer.