OBJECTIVETo investigate the correlation between 18F-fluorodeoxyglucose (18FDG) uptake of primary lesions during PET-CT (positron emission tomography and computed tomography) examination and clinicopathological parameters such as the tumor length, depth of invasion, differentiation of the primary lesions and lymph node metastasis status in the patients with esophageal carcinoma.

METHODSFrom June 2004 to November 2006, 68 operable esophageal carcinoma patients were enrolled into this study, and all had a whole body 18FDG PET-CT scan before operation. The maximum standardized uptake value (SUVmax) of the primary lesions was measured. The tumor length, depth of invasion, differentiation of the primary lesions and lymph node metastasis status were determined by postoperative pathological examination. The correlation between the standardized uptake value (SUV) of primary lesions and the above mentioned clinicopathological parameters was analyzed.

RESULTSThe overall length of primary lesion was positively correlated with SUVmax (r=0.512, P=0.01). Depth of invasion was also positively correlated with SUVmax (r=0.860, P=0.000). There was a statistically significant difference in SUVmax between poorly differentiated group and moderately or well differentiated group (r=0.781, P=0.000), and also between the groups with or without lymph node metastasis (r=0.852, P=0.000).

CONCLUSIONThe tumor length, depth of invasion and differentiation of the primary lesions of the esophageal carcinoma are all positively correlated with maximum standardized uptake value of 18FDG. The more poorly differentiated lesions show a higher 18FDG maximum standardized uptake value. The lesions with lymph node metastasis have also a significantly higher 18FDG maximum standardized uptake value than those without lymph node metastases.