Ultrasonically guided percutaneous microwave coagulation therapy for small hepatocellular carcinoma

Abstract

Background. The authors have used percutaneous microwave coagulation therapy (PMCT) as a new percutaneous local treatment for single unresectable hepatocellular carcinoma (HCC) measuring 2 cm or less in greatest dimension (small HCC). PMCT was used to attempt a cure of the disease. In this study, the efficacy of this treatment was assessed. Methods. PMCT was performed on 18 patients with single small HCC. A microwave electrode (custom‐made, 30‐cm long by 1.6‐mm thick) was inserted percutaneously into the tumor area under ultrasonic guidance. Microwaves at 60 W for 120 seconds were used to irradiate the tumor and surrounding area. Results. After PMCT was administered, various image findings were correlated with tissue necrosis. At the tumor and surrounding area, ultrasonography showed echogenic change, contrast enhancement disappeared on contrast enhanced computed tomography, and magnetic resonance imaging (T2‐weighted image) showed decreased intensity in all cases after treatment. Complete necrosis of the tumor area in a specimen obtained from one patient who underwent hepatectomy after PMCT also was confirmed. The treatment reduced levels of the tumor marker, alpha‐fetoprotein, which had been high in some patients. Although the follow‐up period was short (11‐33 months), 17 patients remain alive. Local recurrence in the treated area has not been detected, and no serious side effects or complications have been encountered. Conclusions. PMCT may be an effective and safe treatment for small HCCs.

Midterm outcomes in patients with intermediate‐sized hepatocellular carcinoma

“…than that with ethanol injection, 8 and the thermal lesions are larger than those obtained with a microwave electrode. 23 However, the limited volume of coagulative necrosis obtained with RF systems and the occasionally irregular burn shape caused by the heat-sink activity of the large vessels in the proximity of the ablated area, have prevented the widespread use of RFA for the treatment of intermediate-to large-sized hepatic tumors. The results of the present study provide evidence that the area of coagulative necrosis, which was determined on the basis of the lengths of the long and short axes of the ablated area, was greater in the TACE-RFA group than in the RFA group, although several insertion techniques 19 were applied to obtain an adequately large ablated area.…”

Asian Pacific Association for the Study of the Liver consensus recommendations on hepatocellular carcinoma

“…Image-guided percutaneous ablation therapies, such as percutaneous ethanol injection [280][281][282], microwave coagulation [283], and radiofrequency ablation (RFA) [284][285][286] have been widely performed on patients with small HCC, generally for those with Child A or B cirrhosis with three or fewer tumors each 3 cm or less in diameter. They are potentially curative, minimally invasive, and easily repeatable for recurrence.…”

“…Percutaneous ethanol injection has been considered a safe procedure, with mortality and morbidity rates of 0-3.2% and 0-0.4%, respectively [289,291,293]. Percutaneous microwave coagulation, in which the cancer tissue is ablated by dielectric heat produced by microwave energy emitted from the inserted 16-gauge, bipolar-type electrode, was introduced into clinical practice in the 1990s and reported to improve local tumor control [283].…”

Radiofrequency ablation for hepatocellular carcinoma in so-called high-risk locations

“…Furthermore, HCV infection, the dominant cause of HCC in various regions including Japan, recurs after transplantation, leading to severe liver damage. 9,10 In the meantime, nonsurgical treatments such as percutaneous ethanol injection therapy (PEIT) [11][12][13] and percutaneous microwave coagulation therapy (PMCT) 14 have played an important role, based on their capability to be used for a wider range of patients.…”