Percutaneous radiofrequency thermal ablation of lung VX2 tumors in a rabbit model using a cooled tip-electrode: feasibility, safety, and effectiveness.
OBJECTIVE
To evaluate the feasibility, safety, and effectiveness of percutaneous CT-guided transthoracic radiofrequency ablation (RFA) of lung VX2 tumors implanted in rabbits.


METHODS
Thirty-five rabbits with implanted lung VX2 tumors were divided into two groups, an RFA group (n = 28) and a control group (n = 7). In the RFA group, RFA was performed on VX2 tumors using a 17-gauge internally cooled-tip electrode. Contrast-enhanced CT was performed before the RFA and on the same day, day 3, weeks 1, 2, 3, and months 1, 2, 6, and 9, after the RFA. The therapeutic efficacy was evaluated by CT and pathologic findings.


RESULTS
RFA of lung tumors was technically successful in each instance. Complete tumor ablation was achieved in 19 of the 28 rabbits (67.9%) in the RFA group. Nine rabbits (32.1%) showed local tumor relapse and mediastinal lymph nodal or pleural metastasis. The animals in the control group died of end-stage malignancies with diffuse tumor spread and malignant pleural effusion (mean 26 +/- 2.7 days). There were 17 (60.7%) complications related to the procedure, ie, pneumothorax (n = 12), obstructive pneumonia (n = 3), hemothorax (n = 1), and burn (n = 1). RFA of centrally located VX2 tumors (in inner 2/3 of the lung) was more frequently associated with complications than RFA of peripherally located VX2 tumors ( P= 0.02).


CONCLUSIONS
This experimental study demonstrates the feasibility of RFA therapy for treating lung VX2 tumors in rabbits, although RFA for central tumors carries the potential for major complications, including large pneumothorax or obstructive pneumonia.
Lee
Jeong Min
JM
Department of Diagnostic Radiology, Chonbuk National University Hospital, Chonbuk, South Korea. jmlshy@naver.com
Jin
Gong Yong
GY
Li
Chun Ai
CA
Chung
Gyung Ho
GH
Lee
Sang Yong
SY
Han
Young Min
YM
Chung
Myoung Ja
MJ
Kim
Chong Soo
CS
D000818:Animals; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D016009:Chi-Square Distribution; D004566:Electrodes; D005240:Feasibility Studies; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008297:Male; D009364:Neoplasm Recurrence, Local; D009368:Neoplasm Transplantation; D011183:Postoperative Complications; D011817:Rabbits; D012449:Safety; D014057:Tomography, X-Ray Computed; D014407:Tumor Cells, Cultured