Radiofrequency tissue ablation: physical principles and techniques for increasing coagulation necrosis

Area of Science:

• Oncology
• Medical Physics
• Minimally Invasive Surgery

Background:

• Radiofrequency tumor ablation (RTA) is a validated technique for inducing thermal coagulation necrosis in malignant tissues.
• Current RTA applications include treating hepatic, cerebral, and bony cancers via percutaneous or surgical approaches.

Purpose of the Study:

• To discuss technical considerations for optimizing radiofrequency ablation parameters.
• To present advanced RTA strategies for increasing coagulation necrosis.
• To review biophysical limitations affecting RTA efficacy.

Main Methods:

• Analysis of conventional monopolar radiofrequency electrode parameters: energy deposition, application duration, and electrode dimensions.
• Presentation of advanced techniques: multiprobe/bipolar arrays, internally-cooled electrodes, pulsed-radiofrequency, and cluster techniques.
• Discussion of laboratory results and biophysical limitations, including perfusion-mediated tissue cooling.

Main Results:

• The extent of coagulation necrosis is directly influenced by energy deposition, application duration, and electrode characteristics.
• Advanced RTA strategies show potential for enhanced necrosis induction.
• Vascular perfusion significantly impacts RTA effectiveness by mediating tissue cooling.

Conclusions:

• Optimizing technical parameters is crucial for maximizing RTA efficacy.
• Novel RTA techniques offer improved therapeutic potential.
• Understanding and mitigating factors like perfusion cooling are essential for successful tumor ablation.