Lung tumors treated with percutaneous radiofrequency ablation: computed tomography imaging follow-up.
OBJECTIVE
To describe the morphologic evolution of lung tumors treated with radiofrequency ablation (RFA) by way of computed tomography (CT) images and to investigate patterns of incomplete RFA at the site of ablation.


METHODS
One hundred eighty-nine patients with 350 lung tumors treated with RFA underwent CT imaging at 2, 4, 6, and 12 months. CT findings were interpreted separately by two reviewers with consensus. Five different radiologic patterns were predefined: fibrosis, cavitation, nodule, atelectasis, and disappearance. The appearance of the treated area was evaluated at each follow-up CT using the predefined patterns.


RESULTS
At 1 year after treatment, the most common evolutions were fibrosis (50.5%) or nodules (44.8%). Differences were noted depending on the initial size of the tumor, with fibrosis occurring more frequently for tumors <2 cm (58.6% vs. 22.9%, P = 1 × 10(-5)). Cavitation and atelectasis were less frequent patterns (2.4% and 1.4%, respectively, at 1 year). Tumor location (intraparenchymatous, with pleural contact <50% or >50%) was not significantly correlated with follow-up image pattern. Local tumor progressions were observed with each type of evolution. At 1 year, 12 local recurrences were noted: 2 cavitations, which represented 40% of the cavitations noted at 1 year; 2 fibroses (1.9%); 7 nodules (7.4%); and 1 atelectasis (33.3%).


CONCLUSIONS
After RFA of lung tumors, follow-up CT scans show that the shape of the treatment zone can evolve in five different patterns. None of these patterns, however, can confirm the absence of further local tumor progression at subsequent follow-up.
Department of Interventional Radiology, Institut Bergonié, Regional Cancer Center, 229 cours de l'Argonne, 33076 Bordeaux Cedex, France. palussiere@bergonie.org
Jean
J
Palussière
Benjamin
B
Marcet
Edouard
E
Descat
Frédéric
F
Deschamps
Pramod
P
Rao
Alain
A
Ravaud
Véronique
V
Brouste
Thierry
T
de Baère
D017115:Catheter Ablation / Q000009:adverse effects; D018450:Disease Progression; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed