FDG positron emission tomography in the surveillance of hepatic tumors treated with radiofrequency ablation.
OBJECTIVE
Radiofrequency thermal ablation (RFA) is an emerging technique in the treatment of focal hepatic tumors. Magnetic resonance imaging (MRI) and computed tomography (CT) are currently used to monitor hepatic tumors after RFA for residual disease and recurrence. Fluorodeoxyglucose (FDG) positron emission tomography (PET) is an excellent imaging method for the detection of liver metastases, but it has not been thoroughly evaluated as an alternative to anatomic imaging in the surveillance of liver tumors treated with RFA. The purpose of this investigation was to determine the role of FDG-PET imaging in the surveillance of liver tumors treated with RFA.


METHODS
Thirteen patients with histories of malignant tumors of the liver treated with RFA and who had received post-treatment FDG-PET scans were assessed retrospectively. One patient had two post-RFA FDG-PET scans, eight patients had concurrent MRI scans, and six patients had concurrent CT scans. Imaging findings were compared with the results of clinical follow-up.


RESULTS
There were either recurrent tumors at the ablation site (8 patients) or new metastases (3 patients) in 11 patients. FDG-PET identified all 11 cases and did not misidentify any cases. Of the seven patients with positive PET findings who received an MRI scan, three were also positive on MRI (42.9%); the other four cases were either negative or equivocal. Of the four patients with positive PET findings who received a CT scan, only two had positive CT scan findings (50%). All recurrences diagnosed by PET were confirmed on clinical follow-up.


CONCLUSIONS
In this preliminary study, FDG-PET was superior to anatomic imaging in the surveillance of patients treated with RFA for malignant hepatic tumors.
Anderson
Gregory S
GS
Division of Nuclear Medicine Univerisity of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA. zhuang@oasis.rad.upenn.edu
Brinkmann
Frank
F
Soulen
Michael C
MC
Alavi
Abass
A
Zhuang
Hongming
H
D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis / Q000000981:diagnostic imaging; D002295:Carcinoma, Transitional Cell / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000556:secondary; D017115:Catheter Ablation; D003110:Colonic Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000556:secondary; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007340:Insulinoma / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000556:secondary; D008113:Liver Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000000981:diagnostic imaging*; D018365:Neoplasm, Residual; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000556:secondary; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012509:Sarcoma / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000556:secondary; D014055:Tomography, Emission-Computed / Q000379:methods*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014915:Whole-Body Counting
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18