Radiofrequency Tissue Ablation with Cooled-Tip Electrodes:An Experimental Study in a Bovine Liver Model on Variables Influencing Lesion Size.
10.3348/jkrs.2001.44.3.351
- Author:
Hyun Young HAN
1
;
Jeong Min LEE
;
Chong Soo KIM
Author Information
1. Department of Diagnostic Radiology, Chonbuk National University Hospital.
- Publication Type:Original Article
- Keywords:
Animals;
Liver, interventional procedure;
Radiofrequency (RF) ablation
- MeSH:
Animals;
Axis, Cervical Vertebra;
Consensus;
Electrodes;
Hyperthermia, Induced;
Liver*;
Necrosis
- From:Journal of the Korean Radiological Society
2001;44(3):351-358
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: The purpose of this study was to determine the influence of various factors on the extent of thermal coagulation necrosis after radiofrequency (RF) tissue ablation using a cooled-tip electrode in bovine liver. MATERIALS AND METHODS: RF ablation was induced by a monopolar 500 KHz-RF generator (CC-1; Radionics,Burlington, Mass., U.S.A.) and an 18-G cooled-tip with single or clustered electrodes. The ablation protocol involveda combination of varying current, ablation time, power output, gradual or abrupt increase of this out-put, and pulsed radiofrequency techniques. The maximum diameter of all thermal lesions which showed a color change was measured perpendicular to the electrode axis by two observers who reached their decisions by consensus. Twenty representative lesions were pathologically examined. RESULTS: With increasing current lesion diameter also increased, but above 1500 mA no further increase was induced. Extending the ablation time to 9 minutes for a single electrode and 15 minutes for a clustered electrode increased lesion diameter until a steady state was reached. Higher power levels caused larger lesions, but above 100 W no increase was observed. Ample exposure time coupled with a stepwise increase in power level induced a lesion larger than that resulting from an abrupt increase. Continuous pulsed RF with a high current led to increased coagulation necrosis diameter. CONCLUSION: These experimental findings may be useful thermotherapy. The data suggest that all involved factors significantly affect lesion size: if the factors are better understood, cancer thermotherapy can be better controlled.
