Role of FDG PET/CT and chest CT in the follow-up of lung lesions treated with radiofrequency ablation.
OBJECTIVE
To compare fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) combined with computed tomography (PET/CT) and chest CT in the evaluation of the effectiveness of lung radiofrequency (RF) ablation.


METHODS
Institutional review board approved the study, and all patients gave written informed consent. Thirty-four patients (22 men and 12 women; mean age, 64 years) planned to undergo lung RF ablation were prospectively included and underwent FDG PET/CT and chest CT before (pre-RF ablation PET) and 24 hours, 1 month, and 3 months after RF ablation. Persistent equivocal findings up to 3 months were followed up.


RESULTS
Pre-RF ablation PET led to changes in the treatment strategy in nine patients (26%) by depicting unexpected metastases. Two patients without FDG uptake in lesions to be treated were excluded. Overall, 28 patients (46 lesions: five primary cancer, 41 metastases) were treated and followed up. Within 3 months after RF ablation, incomplete treatment was diagnosed in four of 28 patients (14%, three at 1 month and one at 3 months). Findings of FDG PET/CT were true-positive in four, false-positive in one, and true-negative in 23 patients. Findings of chest CT were true-positive in one, false-positive in one, false-negative in three, and true-negative in 23 patients. Inflammatory FDG uptake in mediastinal lymph nodes and at the needle path puncture site used for RF ablation was observed in 15%, 21%, and 15% of patients and in 19%, 11%, and 15% of patients at 24 hours, 1 month, and 3 months, respectively.


CONCLUSIONS
FDG PET/CT can be used for the evaluation of the effectiveness of lung RF ablation. Inflammatory FDG uptake in mediastinal lymph nodes or at the needle path site used for RF ablation may occur.
Department of Nuclear Medicine and Endocrine Oncology, Institute Gustave Roussy and University Paris-Sud XI, 39 rue Camille Desmoulins, 94805 Villejuif, France. Desiree.Deandreis@igr.fr
Désirée
D
Deandreis
Sophie
S
Leboulleux
Clarisse
C
Dromain
Anne
A
Auperin
Jérémy
J
Coulot
Jean
J
Lumbroso
Frédéric
F
Deschamps
Pramod
P
Rao
Martin
M
Schlumberger
Thierry
T
de Baère
D017115:Catheter Ablation; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013902:Radiography, Thoracic; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed / Q000379:methods*
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18