Local recurrence after laparoscopic radiofrequency thermal ablation of hepatic tumors

Background: Since we first described laparoscopic radiofrequency ablation ( LRFA) of liver tumors, several reports have documented technical and safety aspects of this procedure. Little is known, however, about the long-term. follow-up of such patients. Methods: From January 1996 to February 1999, we performed LRFA on 250 liver rumors in 66 patients. Triphasic spiral computed tomographic scanning was obtained preoperatively and at 1 week, and every 3 months postoperatively. Lesion diameter was measured in the x- and y-axes and the volume estimated; 181 lesions in 43 patients for whom computed tomographic scans available w ere included in the study. The tumor types were as follows: 64 metastatic a denocarcinomas, 79 neuroendocrine metastases, 27 other metastases, and 11 p rimary liver tumors. Results: One week postoperatively, the ablated zone was larger than the ori ginal tumor in 178 of 181 lesions, which suggests ablation of the tumor and a margin of normal liver tissue. A progressive decline in lesion size was seen in 156 (88%) of 178 lesions, followed for at least 3 months (mean, 13. 9 months; range, 4.9-37.8 months), which suggests resorption of the ablated tissue. Fourteen definite local treatment failures were apparent by increa se in size and change in computed tomographic scan appearance, and eight le sions were scored as failures because of multifocal recurrence that encroac hed on ablated foci (22 total recurrences). predictors of failure include l ack of increased lesion size at 1 week (2 of 3 such lesions failed), adenoc arcinoma or sarcoma (18 of 22 failures; P < .05), larger tumors (failures, M = 18 cm(3) vs. successes, M = 7 cm(3); P < .005) and vascular invasion on laparoscopic ultrasonography, By size criteria, 17 of 22 failures were app arent by 6 months. Energy delivered per gram of tissue was not significantl y different (P = .45). Conclusions: LRFA has a 12% local failure rate, with larger adenocarcinomas and sarcomas at: greatest risk. Failures occur early in follow-up, with mo st occurring by 6 months. LRFA seems to be a safe and effective treatment t echnique for patients with primary and metastatic liver malignancies.