How large is the periablational zone after radiofrequency and microwave ablation? Computer-based comparative study of two currently used clinical devices. (1st January 2020)

• Record Type: Journal Article
• Authors: Trujillo, Macarena; Prakash, Punit; Faridi, Pegah; Radosevic, Aleksandar; Curto, Sergio; Burdio, Fernando; Berjano, Enrique
• Is Part Of: International journal of hyperthermia. Volume 37:Number 1(2020)
• Page Start: 1131
• Page End: 1138
• Publication Date: 2020-01-01
• Subjects: Microwave ablation -- moderate hyperthermic heating -- periablational zone -- radiofrequency ablation -- thermal ablation -- tumor ablation; Thermotherapy -- Periodicals; 615.832
• DOI: 10.1080/02656736.2020.1823022
• Languages: English
• ISSNs: 0265-6736

Abstract

Abstract: Purpose: To compare the size of the coagulation (CZ) and periablational (PZ) zones created with two commercially available devices in clinical use for radiofrequency (RFA) and microwave ablation (MWA), respectively. Methods: Computer models were used to simulate RFA with a 3-cm Cool-tip applicator and MWA with an Amica-Gen applicator. The Arrhenius model was used to compute the damage index ( Ω ). CZ was considered when Ω > 4.6 (>99% of damaged cells). Regions with 0.6< Ω < 2.1 were considered as the PZ (tissue that has undergone moderate sub-ablative hyperthermia). The ratio of PZ volume to CZ volume (PZ/CZ) was regarded as a measure of performance, since a low value implies achieving a large CZ while keeping the PZ small. Results: Ten-min RFA (51 W) created smaller periablational zones than 10-min MWA (11.3 cm 3 vs. 17.2−22.9 cm 3, for 60−100 W MWA, respectively). Prolonging duration from 5 to 10 min increased the PZ in MWA more than in RFA (2.7 cm 3 for RFA vs. 8.3−11.9 cm 3 for 60−100 W MWA, respectively). PZ/CZ for RFA were relatively high (65−69%), regardless of ablation time, while those for MWA were highly dependent on the duration (increase of up to 25% between 5 and 10 min) and on the applied power (smaller values as power was raised, 102% for 60 W vs. 81% for 100 W, both for 10 min). The lowest PZ/CZ across all settings was 56%, obtained with 100 W-5 min MWA. Conclusions: Although RFA creates smaller periablational zones than MWA, 100 W-5 min MWA provides the lowest PZ/CZ.