Published online Nov 8, 2015. doi: 10.4254/wjh.v7.i25.2578
Peer-review started: May 8, 2015
First decision: July 17, 2015
Revised: August 17, 2015
Accepted: October 16, 2015
Article in press: October 19, 2015
Published online: November 8, 2015
Although surgical resection is still the optimal treatment option for early-stage hepatocellular carcinoma (HCC) in patients with well compensated cirrhosis, thermal ablation techniques provide a valid non-surgical treatment alternative, thanks to their minimal invasiveness, excellent tolerability and safety profile, proven efficacy in local disease control, virtually unlimited repeatability and cost-effectiveness. Different energy sources are currently employed in clinics as physical agents for percutaneous or intra-surgical thermal ablation of HCC nodules. Among them, radiofrequency (RF) currents are the most used, while microwave ablations (MWA) are becoming increasingly popular. Starting from the 90s’, RF ablation (RFA) rapidly became the standard of care in ablation, especially in the treatment of small HCC nodules; however, RFA exhibits substantial performance limitations in the treatment of large lesions and/or tumors located near major heat sinks. MWA, first introduced in the Far Eastern clinical practice in the 80s’, showing promising results but also severe limitations in the controllability of the emitted field and in the high amount of power employed for the ablation of large tumors, resulting in a poor coagulative performance and a relatively high complication rate, nowadays shows better results both in terms of treatment controllability and of overall coagulative performance, thanks to the improvement of technology. In this review we provide an extensive and detailed overview of the key physical and technical aspects of MWA and of the currently available systems, and we want to discuss the most relevant published data on MWA treatments of HCC nodules in regard to clinical results and to the type and rate of complications, both in absolute terms and in comparison with RFA.
Core tip: In clinical practice there is an increasing interest in the use of microwave radiations as ablative technique for the treatment of small and intermediate hepatocellular carcinoma nodules. No literature data are already available about a direct comparison between radiofrequency ablation and microwave ablation; in this review we provide an extensive and detailed overview on the technical and engineering aspects of microwave devices, and we critically expose the most relevant clinical data about the experience in microwave ablation, also by making a comparison with radiofrequency ablation.