Use of F-18 Fluorodeoxyglucose Positron Emission Tomography With Dual-Phase Imaging to Identify Intraductal Papillary Mucinous Neoplasm
BACKGROUND & AIMS: We investigated the usefulness of dual-phase, F-18 fluorodeoxyglucose positron emission tomography with computed tomography (FDGPET/CT) to differentiate benign from malignant intraductal papillary mucinous neoplasms (IPMNs) and evaluate branch-duct IPMNs. METHODS: We used FDG-PET/CT to evaluate IPMNs in 48 consecutive patients, from May 2004 to March 2012, who underwent surgical resection. IPMNs were classified as benign (n=16) or malignant (n=32) based on 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 (SUV(max)) 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 SUV(max) cut-off value was set at 2.0, early-phase malignant IPMNs were identified with 88% sensitivity, specificity, and accuracy. The retention index (RI) values for malignant and benign IPMNs were 19.6±17.8 and -2.6±12.9, respectively. When the SUV(max) cut-off was set to 2.0 and the RI 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 SUV(max) cut-off was set to 2.0, the sensitivity, specificity, and accuracy values were 79%, 92%, and 84%, respectively. Using a maximum main pancreatic duct diameter =7 mm, the Guidelines identified branch-duct IPMNs with greater specificity than FDG-PET/CT. The Guideline criteria of maximum cyst size =30 mm and the presence of intramural nodules identified branch-duct IPMNs with almost equal sensitivity to FDGPET/CT. CONCLUSIONS: Dual-phase FDG-PET/CT is useful for preoperative identification of malignant IPMN and for evaluating branch-duct IPMN.
[Show abstract] [Hide abstract] ABSTRACT: The aim of our study is to establish the potential role of dual-phase 18F-fluorodeoxyglucose positron emission tomography / computed tomography (FDG-PET/CT) in patients presenting ovarian masses with diffuse peritoneal infiltration for differentiating benign from malignant lesions. Twenty patients (13 with ovarian cancers and 7 with benign lesions) were evaluated preoperatively by dual-phase 18F-FDG-PET/CT performed 1 h and 2 h after injection of 18F-FDG. The maximum standardized uptake value (SUVmax) for both time points SUVmax1 and SUVmax2 were determined, respectively, and the retention index (RI) was calculated by subtracting the SUVmax1 from the SUVmax2 and dividing by SUVmax1. The areas under the receiver operating characteristic curves (AUCs) of SUVmax1 and SUVmax2 were 0.753 (P = 0.062, 95 % confidence interval [CI] = 0.512-0.915) and 0.835 (P = 0.001, 95 % CI = 0.604-0.961), respectively. The AUC of the RI was 0.901 (P < 0.001, 95 % CI = 0.684-0.988). Using pairwise comparisons, the AUC of SUVmax2 was significantly higher than that of SUVmax1 (P = 0.032). The AUC of the RI was higher than those of SUVmax1 and SUVmax2, but the difference was not statistically significant. Dual-phase 18F-FDG PET/CT might be considered when preoperative imaging is indeterminate. A larger-scaled, prospective study is needed to verify these results.0Comments 3Citations
- "However, many different acquisition protocols have been proposed to overcome the aforementioned false-negative or falsepositive results obtained with 18 F-FDG-PET/CT. Saito et al.  used a protocol involving early-phase and delayed-phase scans (1 h and 2 h after 18 F-FDG administration ) in 48 consecutive patients with intraductal papillary mucinous neoplasia of the pancreas. In this study, SUV max increased further in the delayed phase imaging in 92.3% patients with malignant pancreatic neoplasia, and only 60.0% of those with benign pancreatic neoplasia . "
[Show abstract] [Hide abstract] ABSTRACT: Pancreatic cancer continues to have a grim prognosis with 5-year survival rates at less than 5 %. It is a particularly challenging health problem given these poor survival outcomes, aggressive tumor biology, and late onset of symptoms. Most patients present with advanced unresectable cancer however, margin-negative resection provides a rare chance for cure for patients with resectable disease. The standard imaging modality for the diagnosis and management of pancreatic cancer is contrast-enhanced multidetector computed tomography. Remarkable advances in CT technology have led to improvements in the ability to detect small tumors and intricate vasculature involvement by the tumor, yet CT is still restricted to providing a morphological portrait of the tumor. Diagnosis can be challenging due to similar appearance of certain benign and malignant disease. Distant metastatic disease can be silent on CT leading to improper staging, and thus management, of certain patients. Furthermore, radiation-induced fibrosis and necrosis complicate assessment of treatment response by CT alone. F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) is becoming a prevalent tool employed by physicians to improve accuracy in these clinical scenarios. Malignant transformation causes a high metabolic activity of cancer cells. 18F-FDG-PET captures this functional activity of malignancies by capturing areas with high glucose utilization rates. Imaging function rather than morphological appearance, 18F-FDG-PET has a unique role in the management of oncology patients with the ability to detect regions of tumor involvement that may be silent on conventional imaging. Literature on the sensitivity and specificity of 18F-FDG-PET fails to reach a consensus, and improvements resulting in hybridization of 18F-FDG-PET and CT imaging techniques are preliminary. Here we review the potential role of 18F-FDG-PET and PET/CT in improving accuracy in the initial evaluation and subsequent steps in the management of pancreatic cancer patients.0Comments 1Citation
- "Other studies, however, fail to report such a high sensitivity in detecting malignancy within cystic lesions [33, 34]. Saito et al.  evaluated the usefulness of dual-phase 18 F-FDG-PET/CT with imaging taken at 60 and 120 min after injection of 18 F-FDG. With a combination of SUVmax cutoffs and an index for retention of 18 F-FDG activity in the later scan, the sensitivity and specificity of identifying early malignant IPMNs were 88 and 94 %, respectively. "
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