Microwave Ablation Outperforms Other Modalities in Treatment Times and Sedation

Computed tomography (CT)-guided percutaneous microwave ablation has a treatment response that is similar to that of radiofrequency ablation or cryoablation for the treatment of stage T1N0M0 renal cell carcinoma. Additionally, patients who underwent microwave ablation experienced shorter treatment times and less sedation than those who had radiofrequency ablation or cryoablation.

Radiofrequency ablation and cryoablation are widely used and provide results that compare to surgical resection. Another thermal ablation technique, microwave ablation, is a more recent addition that has shown promise in terms of feasibility and effectiveness. At the current time, operator preference typically guides the choice of modality, the researchers stated. “Our goal was to curate empiric evidence to help guide the clinical choice of ablation modality,” they wrote.

To better understand how microwave ablation compares with radiofrequency and cryoablation, the investigators undertook a retrospective analysis of 384 patients between October 2006 and October 2016. The patients had a total of 437 clinical stage T1N0M0 renal cell carcinomas that were proven by biopsy. The tumors measured 1.2 to 6.9 cm and were treated with CT–guided microwave ablation in 44 cases, radiofrequency ablation in 347 cases, and cryoablation in 46 cases.

Among patients in the three cohorts, complication rates and immediate renal function changes were similar, and patient demographics and tumor characteristics were as well. Microwave ablation was found to have an advantage in several areas. It was linked with significantly decreased ablation time, procedural time, and dosage of sedative medicine.

Functional outcomes in the study were assessed via pre- and postablation serum blood urea nitrogen, creatinine, and estimated glomerular filtration rate, while linear regression analyses were used to compare sedation medication dosages. Rates of residual disease and complications among treatment modalities were compared through univariable and multivariable logistic regression analyses.

“Based on the results of the present study, microwave ablation is at least as tolerable and safe in the short term as cryoablation and radiofrequency ablation,” the authors said. They added, “Despite our encouraging outcomes, future intermediate- and long-term studies are necessary to critically assess the merits and limitations of each ablative modality.”


Zhou W, Arellano RS. Thermal ablation of T1c renal cell carcinoma: a comparative assessment of technical performance, procedural outcome, and safety of microwave ablation, radiofrequency ablation, and cryoablation. J Vasc Interv Radiol. Published online ahead of print. https://doi.org/10.1016/j.jvir.2017.12.020