Results of positron emission tomography with fluorine-18-labelled fluorodeoxyglucose in staging and differential diagnosis of pancreatic cancer

Although the detection of pancreatic carcinoma has been considerably improved by recently developed imaging procedures, differential diagnosis between cancer and benign tumor masses, as well as lymph node staging, is still difficult. In vivo evaluation of regional glucose metabolism by means of positron emission tomography (PET) and fluorine-18-labelled fluorodeoxyglucose (FDG) is a new approach utilizing metabolic instead of morphological tumor properties for diagnosis. Patients and methods: A total of 85 patients with suspected pancreatic carcinoma were investigated by FDG-PET prior to surgery. Static PET scans were evaluated visually as well as quantitatively, taking increased FDG uptake as a sign of malignancy. PET results were correlated with intraoperative findings and histopathology of surgical specimens. Results: Forty-seven out of 55 (85%) malignant tumors and 23 out of 30 (77%) benign lesions were correctly classified by PET, Lymph node metastases were present in 31 patients, 19 of them (61%) positive in PET. In 7 our of 13 (54%) patients with liver metastases, PET detected hypermetabolic lesions. False-negative findings were mainly due to disturbance of glucose metabolism in diabetic patients, while most false-positive results could be attributed to acute inflammatory lesions in chronic pancreatitis. Conclusions: Our results indicate that classification of pancreatic masses can be improved by use of FDG-PET which might lead to a reduction of unnecessary laparotomies in patients with benign or incurable disease.