Usefulness of radiofrequency ablation of liver tumors

AUGUSTOVSKI, F; PICHON-RIVIERE A,; ALCARAZ A; BARDACH, ARIEL; FERRANTE, D; GARCIA MARTÍ, SEBASTIAN; GLUJOVSKY, D; LOPEZ, A; REGUEIRO, A

Documentos de Evaluación de Tecnologías Sanitarias

IECS

Año: 2005 p. 1 - 30

1668-2793

The aim of this review was to assess the efficacy and safety of radiofrequency ablation (RFA) of liver tumors.A bibliographic search was carried out on the main bibliographic databases (MEDLINE, Cochrane, DARE, NHS EED), in general Internet search engines, in sanitary technology evaluation agencies and health suppliers, using the following key words: radiofrequency and hepat*. Priority was given to the inclusion of systematic revisions; controlled randomized clinical trials (CRCT); assessment of sanitary technologies and economic evaluations; clinical practice guidelines and coverage policies of other health systems.A revision carried out by ASERNIP-S (Australian Agency) and published by the National Institute for Clinical Excellence (NICE) of England, based mainly on a systematic revision undertaken by Sutherland et al was identified. Besides, a controlled, randomized clinical trial published (CRCT) by Lin et al was identified after this revision.Sutherland describes a CRCT comparing RFA and a percutaneous ethanol injection (PEI). No differences were observed in mortality at one and two years (0% and 2% versus 4% and 12%) when comparing both techniques. On the other hand, Lin´s work shows longer survival with RFA than with PEI. Sutherland observed that there was a tendency towards less local post-treatment recurrence (RR 0.24, CI 95% 0.05 - 1.04), with a median follow-up of 14 months, and a better long-term tumor control (a 16 month median follow-up) for RFA than for PEI (RR 1.23, CI95% 1.02 - 1.50). He also observed more survival without local recurrence for RFA (98% and 96%) than for PEI (83% and 62%). Lin´s et al study shows similar results at one, two and three years of follow-up. When evaluating safety measures, more adverse effects were observed with RFA than with PEI (fever, pain and analgesics need). The length of hospital stay assessed in a CRCT was shorter for RFA than for PEI (p<0.01), although operative times were longer.As regards surgical resection, the rates of recurrence and the presence of residual disease were significantly higher with RFA than with the surgical treatment. Sutherland et al describe a quasi-experimental study, in which in a 38-month follow-up, and in cases where the tumor diameter was less than 3.5 cm., recurrence in the patients who underwent surgery was 14%, whereas in those treated with RFA, it was 39% (p<0.05). In the same revision, a CRCT is described which compares the use of RFA with microwave coagulation therapy (MCT). No significant differences were found at 18 months with respect to residual disease. In addition, fewer complications are described for RFA, without differences in major complications. On the other hand, a study which compared RFA with laser induced thermotherapyshowed that RFA presents a smaller proportion of residual nodules. Besides, complications such as arterioportal fistulas, liver infarct, focal atrophy and subcapsular fluid collections were also fewer for RFA. When comparing tumor growth control between RFA and a historic control group that used hepatic artery infusion chemotherapy, no statistically significant differences were found (50% vs 30%, p=NS). There were also, fewer complications with RFA than in the control group treated with chemotherapy. No differences are described with respect to mortality rates when RFA is compared with other techniques (except in the paper published by Lin et al). Several health organizations are considering the use of radiofrequency ablation of liver tumors when certain requirements are fulfilled: a) They are not candidates for surgical tumor resection (either because of local involvement, or because of the tumor location or comorbidities); b) there are metastases of an isolated colorectal cancer or a hepatocarcinoma; c) They do not have systemic or extrahepatic disease; d) identification images have been performed (ultrasound or computed tomography); and e) tumors are less than 4 cm in diameter. Those tumors of other origins which are treated with RFA or which are treated for palliative treatment are considered investigational.