Published online Aug 21, 2010. doi: 10.3748/wjg.v16.i31.3964
Revised: May 12, 2010
Accepted: May 19, 2010
Published online: August 21, 2010
AIM: To evaluate the capacity of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for detecting multiple primary cancer of upper gastrointestinal (UGI) tract.
METHODS: Fifteen patients (12 without cancer histories and 3 with histories of upper GI tract cancer) were investigated due to the suspicion of primary cancer of UGI tract on X-ray barium meal and CT scan. Subsequent whole body 18F-FDG PET/CT scan was carried out for initial staging or restaging. All the patients were finally confirmed by endoscopic biopsy or surgery. The detection rate of multiple primary malignant cancers was calculated based on 18F-FDG PET/CT and endoscopic examinations.
RESULTS: 18F-FDG PET/CT scan was positive in 32 suspicious lesions, 30/32 were true positive primary lesions, and 2/32 were false positive. In 15 suspicious lesions with negative 18F-FDG PET/CT scan, 12/15 were true negative and 3/15 were false negative. Among the 15 patients, 12 patients had 29 primary synchronous tumors confirmed by pathology, including 8 cases of esophageal cancers accompanied with gastric cancer and 4 of hypopharynx cancers with esophageal cancer. The other 3 patients had 4 new primary metachronous tumors, which were multiple primary esophageal cancers. PET/CT imaging detected local lymph node metastases in 11 patients. Both local lymph node metastases and distant metastases were detected in 4 patients. On a per-primary lesion basis, the sensitivity, specificity, accuracy, negative predictive value and positive predictive value of 18F-FDG PET/CT for detecting multiple primary cancer of UGI tract were 90.9%, 85.7%, 89.4%, 80% and 93.7%, respectively.
CONCLUSION: The whole body 18F-FDG PET/CT may play an important role in evaluating the multiple primary malignant tumors of UGI tract cancer.