Percutaneous radiofrequency ablation of lung tumors in a large animal model.
OBJECTIVE
Percutaneous radiofrequency ablation (RFA) is accepted therapy for liver tumors in the appropriate clinical setting, but its use in lung neoplasms remains investigational. We undertook this study to evaluate the feasibility and immediate effectiveness of RFA for treatment of both solitary pulmonary nodules and clusters of lung tumors in a large animal model.


METHODS
Percutaneous RFA of 14 lung tumors in five dogs was performed under CT guidance. Animals were euthanatized 8-48 hours after the procedure. The lungs and adjacent structures were harvested for gross and histopathologic evaluation.


RESULTS
Five solitary pulmonary nodules (range, 17-26 mm) and three clusters of three nodules each (range, 7-17 mm per nodule) were treated with RFA. All ablations were technically successful. Perilesional ground-glass opacity and small asymptomatic pneumothoraces (n = 4) were visualized during the RFA sessions. One dog developed a large pneumothorax treated with tube thoracostomy but was euthanatized 8 hours post-RFA for persistent pneumothorax and continued breathing difficulty. Follow-up CT 48 hours post-RFA revealed opacification of the whole lung segment. Gross and histopathologic evaluation showed complete thermal coagulation necrosis of all treated lesions without evidence of any viable tumor. The region of thermal coagulation necrosis typically extended to the lung surface. Small regions of pulmonary hemorrhage and congestion often surrounded the areas of coagulation necrosis.


CONCLUSIONS
RFA can be used to treat both solitary pulmonary nodules and clusters of tumor nodules in the canine lung tumor model. This model may be useful for development of specific RFA protocols for human lung tumors.
Ahrar
Kamran
K
University of Texas M.D. Anderson Cancer Center, the Departments of Diagnostic Radiology, 1515 Holcombe Boulevard, Unit 325, Houston, Texas 77030-4009, USA. kahrar@mdanderson.org
Price
Roger E
RE
Wallace
Michael J
MJ
Madoff
David C
DC
Gupta
Sanjay
S
Morello
Frank A
FA
Wright
Kenneth C
KC
D000818:Animals; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D004285:Dogs; D005240:Feasibility Studies; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D003074:Solitary Pulmonary Nodule / Q000601:surgery; D014057:Tomography, X-Ray Computed