title: Comparison of microwave ablation and multipolar radiofrequency ablation, both using a pair of internally cooled interstitial applicators: results in ex vivo porcine livers.
abstract: OBJECTIVE
  To compare the effectiveness of microwave ablation (MWA) and multipolar radiofrequency ablation (RFA) in ex vivo porcine livers, in both cases using a pair of internally cooled interstitial applicators.
  
  
  METHODS
  MWA was performed on ex vivo porcine livers (n = 60) using a pair of simultaneously powered, internally cooled shaft interstitial antennae. Four power settings were used: 50 W, 60 W, 70 W and 80 W (n = 15 per setting). Multipolar RFA was also performed on ex vivo porcine livers (n = 30), also using a pair of simultaneously powered, internally cooled shaft interstitial bipolar applicators. This was performed for two applicator types T30 (3 cm length) and T40 (4 cm length) at a manufacturer prescribed power of 60 W and 80 W, respectively (n = 15 per applicator). Spacing between the two probes was 2 cm in all cases. Each power setting was applied for 15 ablations for 10 min each. The long-axis diameter (Dl), short-axis diameter (Ds) and the ratio Ds/Dl for each ablation were measured. Temperature data were recorded at 10 positions. Temperature curves were recorded at 3 locations, as well as the time required for the temperature to rise to 50°C.
  
  
  RESULTS
  Dl and Ds for all the power settings of MWA were significantly larger than that of both kinds of multipolar RFA (P < 0.05). The rates of temperature to rise to 50°C in all the MW ablations power settings were significantly faster than those in both multipolar RF ablations.
  
  
  CONCLUSIONS
  MWA by the simultaneous application of double antennae may be more advantageous for treating larger liver tumour than multipolar RFA.
authors.affiliation: Department of Medical Imaging and Interventional Radiology, Cancer Centre and State Key Laboratory of Oncology in South China, Sun Yat-Sen University, No. 651 Dongfeng East Road, Guangzhou, Guangdong Province, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Liang
authors.initials: L
authors.lastname: Zhang
authors.forename: Weijun
authors.initials: W
authors.lastname: Fan
authors.forename: Ming
authors.initials: M
authors.lastname: Zhao
authors.forename: Ligang
authors.initials: L
authors.lastname: Wang
authors.forename: Tian
authors.initials: T
authors.lastname: Tang
authors.forename: Hua
authors.initials: H
authors.lastname: Jiang
authors.forename: Jianlei
authors.initials: J
authors.lastname: Zhang
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods*; D004867:Equipment Design; D006801:Humans; D008099:Liver / Q000473:pathology / Q000528:radiation effects* / Q000601:surgery*; D008113:Liver Neoplasms / Q000473:pathology / Q000601:surgery; D008872:Microwaves; D000078702:Radiofrequency Therapy; D034421:Sus scrofa; D013696:Temperature