title: Thermal ablation of lung tissue: in vivo experimental comparison of microwave and radiofrequency.
abstract: This study was designed to compare feasibility, safety, and effectiveness of microwave (MW) ablation versus radiofrequency (RF) ablation of lung tissue in a rabbit model. Twenty New Zealand White rabbits were submitted to MW (n = 10, group A) or RF ablation (n = 10, group B). The procedures were performed with a prototype MW ablation device with a 1.6-cm radiating section antenna (Valleylab MW Ablation System) and with a 2-cm exposed-tip RF electrode (Cool-tip RF Ablation System). At immediate computed tomography increase in density, maximum diameters (D1-D3) of ablation zones were measured and ablation volume was calculated. Histopathologic assessment was performed 3 and 7 days after the procedure. Technical success was achieved in nine of 10 rabbits in each group. One death occurred in group B. Complications included pneumothorax (group A, n = 4; group B, n = 4), abscess (group A, n = 1; group B, n = 1), and thoracic wall burn (group A, n = 4). No significant differences were demonstrated in attenuation increase (P = 0.73), dimensions (P = 0.28, 0.86, 0.06, respectively, comparing D1-D3) and volume (P = 0.17). At histopathology, ablation zones were similar, with septal necrosis, edema, hemorrhage, and peripheral lymphocytic infiltrate. Complete thrombosis of more than 90% of vessels up to 2 mm in diameter was depicted at the periphery of the ablation zone in group A specimens. In group B specimens, complete thrombosis was depicted in 20% of vessels. Feasibility and safety of MW and RF ablation are similar in a lung rabbit model. MW ablation produces a greater damage to peripheral small vessels inducing thrombosis.
authors.affiliation: Division of Radiodiagnostic, Department of Oncological and Radiological Sciences, Pisa University Hospital, Pisa, Italy. l.crocetti@med.unipi.it
authors.forename: Laura
authors.initials: L
authors.lastname: Crocetti
authors.forename: Elena
authors.initials: E
authors.lastname: Bozzi
authors.forename: Pinuccia
authors.initials: P
authors.lastname: Faviana
authors.forename: Dania
authors.initials: D
authors.lastname: Cioni
authors.forename: Clotilde
authors.initials: C
authors.lastname: Della Pina
authors.forename: Alberto
authors.initials: A
authors.lastname: Sbrana
authors.forename: Gabriella
authors.initials: G
authors.lastname: Fontanini
authors.forename: Riccardo
authors.initials: R
authors.lastname: Lencioni
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000379:methods*; D005240:Feasibility Studies; D008168:Lung / Q000000981:diagnostic imaging* / Q000601:surgery*; D008872:Microwaves; D023421:Models, Animal; D011817:Rabbits; D015642:Radiology, Interventional / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods