The clinical value of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in postoperative patients with gastrointestinal mucinous adenocarcinoma.

OBJECTIVE

To evaluate the clinical value of F-fluorodeoxyglucose positron emission tomography and computed tomography (¹⁸F-FDG PET/CT) in postoperative patients with gastrointestinal mucinous adenocarcinoma.

METHODS

From July 2007 to March 2009, 30 patients who had previous surgical resection of histopathologically diagnosed gastrointestinal mucinous adenocarcinoma underwent ¹⁸F-FDG PET/CT scans in our center. The standard of reference for tumor recurrence, regional lymph node (LN) metastasis, peritoneal and distant metastasis consisted of histopathologic confirmation or clinical follow-up information for at least 6 months after PET/CT examinations.

RESULTS

With final diagnosis, tumor recurrences were confirmed in eight of the 30 patients (26.7%). If a maximum standardized uptake value (SUVmax) of 2.5 or more was used as a cut-off point, the sensitivity, specificity, and accuracy of PET/CT were 87.5, 77.3, and 80.0%, respectively. However, if an SUVmax of 4.0 or more was the criterion, the sensitivity, specificity, and accuracy were 25.0, 86.4, and 70.0%, respectively. A cut-off point of 2.5 showed a higher sensitivity (P=0.041), and there was no statistical difference in the specificity and the accuracy of these two criteria. For the diagnosis of metastasis in regional LNs and peritoneum, the detection rate was 95.2 and 86.4%, respectively. In addition, we followed up 20 patients with 26 suspicious distant lesions. The sensitivity, specificity, and accuracy were 58.3, 92.9, and 76.9%, respectively.

CONCLUSION

¹⁸F-FDG PET/CT may be effective to discriminate tumor recurrence, and to detect regional LNs, peritoneal and distant metastasis in postoperative patients with gastrointestinal mucinous adenocarcinoma.