05). For PET/CT, a blind designed or non-blind designed study was the possible source of heterogeneity in PET/CT (P < 0.05). In subgroup analysis, the sensitivity of enhanced versus unenhanced PET/CT in the detection of pancreatic cancer was 0.91 (95% CI, 0.86–0.96) versus 0.84 (95% CI, 0.78–0.90), the specificity 0.88 (95% CI, 0.73–1.00) versus 0.81 (95% CI, 0.69–0.94), but there were no significant differences (P > 0.05). In this meta-analysis, we found that FDG-PET/CT was highly sensitive and DWI was a highly specific diagnostic modality for patients suspected to have pancreatic cancer. FG-4592 molecular weight This indicates that PET/CT and DWI could play

different roles in diagnosing pancreatic carcinoma. But the diagnostic value of PET/CT and DWI is restricted by its high heterogeneity. To explore sources of heterogeneity in the studies for PET/CT and DWI, the meta-regression analysis was performed. The heterogeneity for PET/CT and DWI is caused by other factors like study characteristics and imaging

techniques. The results of meta-regression analysis indicate that the subgroup of lesion size is the most important characteristic, which significantly influenced its diagnostic accuracy for DWI. A blind designed or non-blind designed study was the possible source of heterogeneity in PET/CT. More recently, a study confirmed that the use of enhanced PET/CT was accurate and superior to unenhanced PET/CT in find more the assessment of resectability.17 Kauhanen et al.34 also reported PET/CT combined with contrast-enhanced MDCT could be used as a first-line imaging method in patients with suspicion of pancreatic cancer to detect optimally unexpected metastatic lesions and FDG-negative histologic types. Similar results were published by Farma et al.39 Our further subgroup analysis showed that contrast enhanced PET/CT seems to be superior to non-contrast PET/CT as well. However, the use of CT contrast agents in PET/CT is still controversial.

Some argue that CT image data should be used only for attenuation selleck inhibitor correction of PET, reduction of acquisition time, and localization of hypermetabolic lesions with a low radiation dose,42,43 whereas others advocate the need to perform contrast-enhanced, full-dose, and high resolution CT (“diagnostic CT”) in various types of cancer.44,45 Some reports have stated that there is an increase in standardized uptake value in normal and pathologic regions of high concentration when intravenous contrast-enhanced CT is used for attenuation; this increase is clinically insignificant in the evaluation of patients with cancer, and contrast-enhanced CT could be used for attenuation correction.44 Further study in larger patient populations is needed to elucidate the efficacy, radiation exposure, and cost-effectiveness of PET/contrast-enhanced CT. In the present study, DWI appears to be a highly specific modality for pancreas cancer.