Clinical role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in post-operative follow up of gastric cancer: initial results.
OBJECTIVE
To evaluate the clinical role of (18)F-fluorodeoxyglucose positron emission and computed tomography ((18)F-FDG PET/CT) in detection of gastric cancer recurrence after initial surgical resection.


METHODS
In the period from January 2007 to May 2008, 23 patients who had previous surgical resection of histopathologically diagnosed gastric cancer underwent a total of 25 (18)F-FDG PET/CT scans as follow-up visits in our center. The standard of reference for tumor recurrence consisted of histopathologic confirmation or clinical follow-up information for at least 5 mo after PET/CT examinations.


RESULTS
PET/CT was positive in 14 patients (61%) and negative in 9 (39%). When correlated with final diagnosis, which was confirmed by histopathologic evidence of tumor recurrence in 8 of the 23 patients (35%) and by clinical follow-up in 15 (65%), PET/CT was true positive in 12 patients, false positive in 2, true negative in 8 and false negative in 2. Overall, the accuracy of PET/CT was 82.6%, the negative predictive value (NPV) was 77.7%, and the positive predictive value (PPV) was 85.7%. The 2 false positive PET/CT findings were actually chronic inflammatory tissue lesions. For the two patients with false negative PET/CT, the final diagnosis was recurrence of mucinous adenocarcinoma in the anastomosis in one patient and abdominal wall metastasis in the other. Importantly, PET/CT revealed true-positive findings in 11 (47.8%) patients who had negative or no definite findings by CT. PET/CT revealed extra-abdominal metastases in 7 patients and additional esophageal carcinoma in one patient. Clinical treatment decisions were changed in 7 (30.4%) patients after introducing PET/CT into their conventional post-operative follow-up program.


CONCLUSIONS
Whole body (18)F-FDG PET/CT was highly effective in discriminating true recurrence in post-operative patients with gastric cancer and had important impacts on clinical decisions in a considerable portion of patients.
Sun
Long
L
Minnan PET Center and Department of Nuclear Medicine, the First Hospital of Xiamen, Fujian Medical University, Xiamen, Fujian Province, China.
Su
Xin-Hui
XH
Guan
Yong-Song
YS
Pan
Wei-Ming
WM
Luo
Zuo-Ming
ZM
Wei
Ji-Hong
JH
Wu
Hua
H
D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography / Q000379:methods; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D014057:Tomography, X-Ray Computed / Q000379:methods
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18