International Journal of Bioelectronics

Microwave Ablation in Tumors: A State of the Art Review

Abstract

This review summarizes the state of the art of microwave ablation (MWA) for tumors in organs such as liver, lung, kidney, and breast, highlighting its role as a minimally invasive option for patients who are not candidates for surgery. The paper outlines tumor biology, compares ablation techniques (RFA, cryoablation, laser), and compiles clinical and preclinical evidence supporting MWA as a compelling alternative. Keywords: Tumor, Ablation, Microwave.

Introduction

A tumor is an abnormal mass of cells that can be benign or malignant. Malignant tumors may invade nearby tissues and metastasize via lymphatic or hematogenous routes. The review introduces basic concepts and tumor classes (carcinomas and sarcomas) before discussing energy-based ablation therapies.

Tumor Ablation

When surgery is not feasible, tumors may be destroyed by heat, cold, or chemicals delivered through percutaneous probes. RFA uses electrical current to heat tissue; cryoablation freezes it; other methods include laser-induced interstitial thermotherapy and ethanol ablation. MWA is increasingly favored due to larger active heating zones and reduced heat-sink sensitivity compared with RFA.

State of the Art in Microwave Ablation (MWA)

Modern MWA relies on interstitial antennas engineered to focus energy while sparing healthy tissue. Designs include internally cooled antennas that prevent shaft overheating (< ~20 °C) versus non-cooled variants (>90 °C), multiple-slot coaxial designs, and multi-antenna phase-controlled arrays. Simulation studies (e.g., COMSOL-based) show that phase differences between antennas (0°–180°) significantly affect ablation patterns, informing multi-antenna strategies.

Evidence by Organ

• Liver: Preclinical porcine/bovine studies report ablation zones of ~3–6.5 cm at 2.45 GHz; large human series (e.g., Livraghi et al.) show low complication and zero mortality rates across hundreds of patients.
• Lung: High-energy antennas (120–180 W) achieved ~88% ablation control with procedure times adjusted to tumor size (e.g., 2–6 min).
• Kidney: Comparative studies versus partial nephrectomy report intermediate-term survival of ~91% (MWA) vs ~96% (surgery) with 14–15G applicators.
• Breast: The review references proposals and doctoral work suggesting MWA feasibility; clinical human series were not yet reported at the time of writing.

Conclusion

MWA has demonstrated safety and efficacy across multiple organs, offering a minimally invasive alternative where resection is not possible. Wider clinical adoption requires dissemination, equipment availability, and continued validation with clear communication of risks and benefits to patients.

References

See original article for the full reference list.

© International Journal of Bioelectronics (IJBIOE). Article licensed under CC BY 4.0.