Utility of FDG-PET for investigating unexplained serum AFP elevation in patients with suspected hepatocellular carcinoma recurrence.
The aim of this study was to evaluate the potential role of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) in patients with unexplained rising serum alpha-fetoprotein (AFP) levels after the treatment of hepatocellular carcinoma (HCC).


METHODS
Thirty-one FDG-PET studies were performed in 26 patients (age range, 45-83; 21 men and 5 women), who had undergone either surgical resection or interventional therapy for HCC, but were subsequently noted to have high AFP serum levels on routine follow-up examinations, although imaging studies and physical examinations were normal. The FDG-PET results were correlated with histological findings, as well as long-term radiological and clinical follow-up (shortest follow-up period after FDG-PET was 6 months).


RESULTS
FDG-PET was abnormal in 22 of the 31 studies (71.0%) among the 26 patients. Intrahepatic lesions were detected in 20 of a total 30 lesions (66.7%) in 18 studies of FDG-PET among 26 patients. Ten FDG-PET studies among 9 patients identified one intrahepatic lesion, while 3 studies among 3 patients identified more than one intrahepatic lesion. Extrahepatic metastases were found in 9/31 studies of FDG-PET (29.0%) among 8 patients. These metastatic foci, composed of increased FDG accumulation, were identified in several locations; lung (4 studies among 4 patients), bone (2 studies among 2 patients) and the peritoneum (4 studies among 3 patients). Overall, FDG-PET for detecting HCC recurrence demonstrated 22 true-positives, 8 false-negatives, 1 true-negative and 0 false-positive results., The sensitivity, specificity and accuracy of FDG-PET for detecting HCC recurrence was 73.3%, 100% and 74.2%, respectively.


CONCLUSIONS
When conventional examinations are normal, FDG-PET is a valuable imaging tool in patients who have rising AFP levels after HCC treatment. FDG-PET whole-body scan also provides an important and valuable imaging study for detecting extrahepatic metastasis.
Chen
Yen-Kung
YK
Department of Nuclear Medicine and PET Center, Shin Kong Wu Ho-Su Memorial Hospital, Taipei and China Medical University, Taichung, Taiwan.
Hsieh
Dar-Shih
DS
Liao
Chao-Sheng
CS
Bai
Chyi-Huey
CH
Su
Chen-Tau
CT
Shen
Yeh-You
YY
Hsieh
Jih-Fang
JF
Liao
Alfred C
AC
Kao
Chia-Hung
CH
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000097:blood* / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D008113:Liver Neoplasms / Q000097:blood* / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012189:Retrospective Studies; D000509:alpha-Fetoproteins / Q000378:metabolism*
D019275:Radiopharmaceuticals; D000509:alpha-Fetoproteins; D019788:Fluorodeoxyglucose F18