Positron emission tomography in gastric and esophageal cancer

Positron emission tomography using the positron emitting glucose analogue 18F-fluorodeoxyglucose has recently emerged as a promising metabolism-based whole-body imaging tool for cancer diagnosis and follow-up. Several reports have recently appeared indicating the potential and limitations of this technique. The review limits its scope to the recent advances of 18F-fluorodeoxyglucose positron emission tomography in the clinical management of gastric and esophageal cancer.

New studies have been reported on the use of 18F-fluorodeoxyglucose positron emission tomography to assess the early and late metabolic response of a gastroesophageal tumor to chemo(radiation) therapy. The metabolic response as measured by serial 18F-fluorodeoxyglucose positron emission tomography, performed before and during treatment or some weeks thereafter, can be used to predict the clinical and histopathologic response. Moreover, the metabolic positron emission tomography response seems to be related to overall and disease-free survival.

Gastroesophageal 18F-fluorodeoxyglucose positron emission tomography could add significant diagnostic information to the different phases of patient management. At initial diagnosis of esophageal cancer, positron emission tomography detects more distant lymph node and organ metastases compared with conventional diagnostics, allowing a more accurate selection of the most appropriate treatment. Serial 18F-fluorodeoxyglucose positron emission tomography performed before and during chemotherapy allows early identification of nonresponding tumors. 18F-fluorodeoxyglucose positron emission tomography performed after a treatment allows accurate assessment of the residual tumor load. 18F-fluorodeoxyglucose positron emission tomography allows accurate detection and restaging of recurrent disease.