Treatment of hepatocellular carcinoma using internally cooled electrodes. A prospective comparison of modified automated vs. manual pulsed radiofrequency algorithms.

OBJECTIVES

To compare the effectiveness of modified automated and manual pulsed radiofrequency (RF) algorithms using internally cooled electrodes for hepatocellular carcinoma (HCC).

METHODS

Seventy-seven treatment-naive cirrhotic patients with 102 HCC (< or =4 cm) underwent 109 sessions of ultrasound-guided percutaneous RF ablation using a 17-gauge, 20-cm-long, single internally cooled electrode. Patients were assigned alternatively: 40 patients to the modified automated algorithm group and 37 patients to the manual algorithm group. The mean tumor diameters were 2.34 +/- 0.9 and 2.25 +/- 0.7 cm in the automated and manual groups, respectively (p = 0.56). Primary technique effectiveness and local tumor progression were compared between the two groups.

RESULTS

More overlapping ablations (n = 112) were required in the manual than in the automated group (n = 82) to achieve similar primary technique effectiveness rates of 96.1 and 94.1%, respectively. After a mean follow-up period of 26.7 +/- 1.1 months, the local tumor progression rates at 12 and 18 months were 4 and 20% in the manual group and 12 and 24% in the modified automated group (p = 0.3). Only tumors >3 cm were independently associated with local tumor progression (odds ratio 1.25; 95% CI 1.06-2.34, p = 0.03).

CONCLUSIONS

The manual algorithm requires more overlapping ablations and treatment sessions in order to achieve similar primary technique effectiveness and local tumor progression rates compared with the modified automated algorithm.