Use of F-18 fluorodeoxyglucose positron emission tomography with dual-phase imaging to identify intraductal papillary mucinous neoplasm

Abstract

Background & aims: We investigated the usefulness of dual-phase F-18 fluorodeoxyglucose positron emission tomography with computed tomography (FDG-PET/CT) to differentiate benign from malignant intraductal papillary mucinous neoplasms (IPMNs) and to evaluate branch-duct IPMNs.

Methods: We used FDG-PET/CT to evaluate IPMNs in 48 consecutive patients who underwent surgical resection from May 2004 to March 2012. IPMNs were classified as benign (n = 16) or malignant (n = 32) on the basis of histology analysis. The ability of FDG-PET/CT to identify branch-duct IPMNs was compared with that of the International Consensus Guidelines.

Results: The maximum standardized uptake value (SUVmax) was higher for early-phase malignant IPMNs than that for benign IPMNs (3.5 ± 2.2 vs 1.5 ± 0.4, P < .001). When the SUVmax cutoff value was set at 2.0, early-phase malignant IPMNs were identified with 88% sensitivity, specificity, and accuracy. The retention index values for malignant and benign IPMNs were 19.6 ± 17.8 and -2.6 ± 12.9, respectively. When the SUVmax cutoff was set to 2.0 and the retention index value to -10.0, early-phase malignant IPMNs were identified with 88% sensitivity, 94% specificity, and 90% accuracy. In identification of branch-duct IPMNs, when the SUVmax cutoff was set to 2.0, the sensitivity, specificity, and accuracy values were 79%, 92%, and 84%, respectively. By using a maximum main pancreatic duct diameter ≥7 mm, the Guidelines identified branch-duct IPMNs with greater specificity than FDG-PET/CT. The Guidelines criteria of maximum cyst size ≥30 mm and the presence of intramural nodules identified branch-duct IPMNs with almost equal sensitivity to FDG-PET/CT.

Conclusions: Dual-phase FDG-PET/CT is useful for preoperative identification of malignant IPMN and for evaluating branch-duct IPMN.