[Percutaneous cryoablation therapy under local anesthesia for unresectable metastatic liver tumors]

Even though liver resection is the first choice against metastatic liver tumors, oncologists are often obliged to include other treatment modalities depending on metastatic tumor size, number of metastatic nodules, location of tumors, patient's general condition, and so on. Among others we selected cryoablation therapy against unresectable tumors and examined its usefulness clinically in 5 patients. Under local anesthesia, the cryoprobe, which was 3 mm in diameter, was introduced into the center of the tumor by use of an ultrasonographic guiding technique. In the middle of the freezing process, through ultrasonography we could clearly monitor the target tumor, which would change into an ice ball. It was noteworthy that not only the treated tumor but also untreated tumors were reduced in 2 cases. Because of extra-hepatic metastases, 3 patients died within 1 year after the therapy, while 2 patients are alive. This modality was easily repeatable and was minimally invasive with little toxic effect. In addition, it did not worsen quality of life (QOL). The above results indicate that cryoablation therapy could be a feasible modality against unresectable metastatic liver tumors.