title: Microwave ablation of primary and secondary liver tumours: ex vivo, in vivo, and clinical characterisation.
abstract: The aim of this study was to compare the performance of a microwave ablation (MWA) apparatus in preclinical and clinical settings.
  
  
  
  The same commercial 2.45 GHz MWA apparatus was used throughout this study. In total 108 ablations at powers ranging from 20 to 130 W and lasting from 3 to 30 min were obtained on ex vivo bovine liver; 28 ablations at 60 W, 80 W and 100 W lasting 5 and 10 min were then obtained in an in vivo swine model. Finally, 32 hepatocellular carcinomas (HCCs) and 19 liver metastases in 46 patients were treated percutaneously by administering 60 W for either 5 or 10 min. The treatment outcome was characterised in terms of maximum longitudinal and transversal axis of the induced ablation zone.
  
  
  
  Ex vivo ablation volumes increased linearly with deposited energy (r2= 0.97), with higher sphericity obtained at lower power for longer ablation times. Larger ablations were obtained on liver metastases compared to HCCs treated with 60 W for 10 min (p < 0.003), as ablation diameters were 4.1 ± 0.6 cm for metastases and 3.7 ± 0.3 cm for HCC, with an average sphericity index of 0.70 ± 0.04. The results on the in vivo swine model at 60 W were substantially smaller than the ex vivo and clinical results (either populations). No statistically significant difference was observed between ex vivo results at 60 W and HCC results (p > 0.08).
  
  
  
  For the selected MW ablation device, ex vivo data on bovine liver was more predictive of the actual clinical performance on liver malignancies than an in vivo porcine model. Equivalent MW treatments yielded a significantly different response for HCC and metastases at higher deposited energy, suggesting that outcomes are not only device-specific but must also be characterised on a tissue-by-tissue basis.
authors.affiliation: a R&D Unit , H.S. Hospital Service SpA , Rome , Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Amabile
authors.affiliation: b Department of Radiology , Beth Israel Deaconess Medical Center, Harvard Medical School , Boston , Massachusetts , USA.
authors.forename: Muneeb
authors.initials: M
authors.lastname: Ahmed
authors.affiliation: c Department of Interventional Oncologic Radiology , General Hospital of Busto Arsizio , Busto Arsizio , Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Solbiati
authors.affiliation: d Department of Radiology , San Gerardo Hospital , Monza , Italy.
authors.forename: Maria Franca
authors.initials: MF
authors.lastname: Meloni
authors.affiliation: e Department of Electronics, Information and Bioengineering , Politecnico di Milano , Milan , Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Solbiati
authors.affiliation: a R&D Unit , H.S. Hospital Service SpA , Rome , Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Cassarino
authors.affiliation: a R&D Unit , H.S. Hospital Service SpA , Rome , Italy.
authors.forename: Nevio
authors.initials: N
authors.lastname: Tosoratti
authors.affiliation: e Department of Electronics, Information and Bioengineering , Politecnico di Milano , Milan , Italy.
authors.forename: Yitzhak
authors.initials: Y
authors.lastname: Nissenbaum
authors.affiliation: c Department of Interventional Oncologic Radiology , General Hospital of Busto Arsizio , Busto Arsizio , Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Ierace
authors.affiliation: b Department of Radiology , Beth Israel Deaconess Medical Center, Harvard Medical School , Boston , Massachusetts , USA.|f Department of Radiology , Hadassah Hebrew University Medical Centre , Jerusalem , Israel.
authors.forename: S Nahum
authors.initials: SN
authors.lastname: Goldberg
mesh_terms: D055011:Ablation Techniques; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000556:secondary / Q000601:surgery*; D002417:Cattle; D005260:Female; D006801:Humans; D008099:Liver / Q000601:surgery; D008113:Liver Neoplasms / Q000556:secondary / Q000601:surgery*; D008297:Male; D008872:Microwaves / Q000627:therapeutic use*; D008875:Middle Aged; D013552:Swine; D016896:Treatment Outcome
keywords: Ablation; comparison; ex vivo; in vivo; microwave; tumour