Which Modality is Best for Diagnosing Pancreatic Cancer?

Researchers from Shanghai Jiao Tong University School of Medicine in China conducted a meta-analysis to compare the diagnostic value of fluorodeoxyglucose (FDG)-positron emission tomography (FDG-PET) scanning versus endoscopic ultrasonography (EUS) versus combined FDG-PET and computed tomography scanning (PET/CT) in diagnosing pancreatic carcinoma. They searched several databases (MEDLINE, EMBASE, Cochrane Library, etc) for all studies in English or Chinese between January 1996 to April 2009 that investigated the diagnostic value of these three imaging techniques. After assessing methodological quality, the researchers decided to include 51 of the identified studies in their analysis.

Data analysis determined the pooled sensitivity for combined PET/CT was 90.1%, significantly higher than the 88.4% sensitivity of FDG-PET alone and the 81.2% sensitivity of EUS. Although lowest in sensitivity, EUS was highest for specificity, at 93.2% versus 83.1% for FDG-PET and 80.1% for PET/CT.

The investigators estimated a pooled diagnostic odds ratio (DOR) of 49.774 for EUS, which was significantly higher than the DOR for FDG-PET (32.778) and PET/CT (27.105). The diagnostic value of EUS decreased when used to differentiate pancreatic cancer from chronic pancreatitis.

The researchers concluded that PET/CT was highly sensitive and EUS was highly specific in diagnosing pancreatic cancer. Pancreatic cancer is difficult to diagnose in its early stages, and other studies have indicated that EUS is superior to CT scanning at detecting smaller pancreatic tumors. The investigators suggested that EUS and PET/CT might have different roles to play in diagnosing pancreatic carcinoma dependent on the patient’s condition. Results were published in the European Journal of Radiology.