Staging pancreatic carcinoma by computed tomography

The diagnostic accuracy of endoscopic ultrasound vs. contrast-enhanced computed tomography in local staging of pancreatic adenocarcinoma: a bi-national multicenter study

BACKGROUND

Identification of pancreatic cancer (PC) local invasion is crucial to optimize patients' selection for surgery.

AIMS

To determine the diagnostic accuracy of contrast-enhanced computed tomography (CECT) and endoscopic ultrasound (EUS) in local staging of PC.

METHODS

We performed a multicenter study including all patients with PC who underwent surgery.

RESULTS

One hundred twelve patients were included. Surgical findings of peri-pancreatic lymph nodes (LN), vascular and adjacent organ involvement were seen in 67 (59.8%), 33 (29.5%) and 19 patients (17%), respectively. The diagnostic performance of EUS was better than CECT in peri-pancreatic LN. The sensitivity, specificity, positive predictive value (PPV) and negative predictive (NPV) of CECT vs. EUS were 28.4%, 80%, 67.9% and 42.9% vs. 70.2%, 75.6%, 81% and 63%, respectively. For vascular and adjacent organ involvement, the sensitivity, specificity, PPV and NPV were 45.5%, 93.7%, 75%, 80.4% and 31.6%, 89.2%, 37.5% and 86.5% for CECT, respectively, vs. 63.6%, 93.7%, 80.8%, 86.1% and 36.8%, 94.6%, 58.3% and 88% for EUS, respectively. Combining both CECT and EUS, the sensitivity for peri-pancreatic LN, vascular and adjacent organ involvement improved (76.1%, 78.8% and 42%), respectively.

CONCLUSION

EUS was superior to CECT in local staging. Combined EUS and CECT had a higher sensitivity than either alone.

Diagnosis of Pancreatic Ductal Adenocarcinoma by Immuno-Positron Emission Tomography

Diagnosis of pancreatic ductal adenocarcinoma (PDAC) by current imaging techniques is useful and widely used in the clinic but presents several limitations and challenges, especially in small lesions that frequently cause radiological tumors infra-staging, false-positive diagnosis of metastatic tumor recurrence, and common occult micro-metastatic disease. The revolution in cancer multi-"omics" and bioinformatics has uncovered clinically relevant alterations in PDAC that still need to be integrated into patients' clinical management, urging the development of non-invasive imaging techniques against principal biomarkers to assess and incorporate this information into the clinical practice. "Immuno-PET" merges the high target selectivity and specificity of antibodies and engineered fragments toward a given tumor cell surface marker with the high spatial resolution, sensitivity, and quantitative capabilities of positron emission tomography (PET) imaging techniques. In this review, we detail and provide examples of the clinical limitations of current imaging techniques for diagnosing PDAC. Furthermore, we define the different components of immuno-PET and summarize the existing applications of this technique in PDAC. The development of novel immuno-PET methods will make it possible to conduct the non-invasive diagnosis and monitoring of patients over time using in vivo, integrated, quantifiable, 3D, whole body immunohistochemistry working like a "virtual biopsy".

CT and MR features that can help to differentiate between focal chronic pancreatitis and pancreatic cancer

Diagnosis of a focal pancreatic mass in routine clinical practice can be a challenge because patients with chronic pancreatitis may present with symptoms and imaging findings that can be difficult to distinguish from pancreatic cancer. Markers, such as cancer antigen 19-9 and carcinoembryonic antigen, are helpful if abnormal, but normal values do not rule out pancreatic cancer. One of the strongest complicating factors is that chronic pancreatitis is a risk factor for pancreatic cancer. Transition of chronic pancreatitis to pancreatic cancer is relatively rare, but it normally has a poor prognosis because diagnosis is often delayed. From a radiologic diagnosis perspective, the classic so-called double-duct sign is helpful. This sign is considered a hallmark sign of pancreatic cancer on magnetic resonance cholangiopancreatography, but it can also be identified in patients with chronic pancreatitis or with other conditions. A number of additional imaging findings or signs are, therefore, necessary. The aim of this article was to describe the strong CT and MR imaging features or integrated imaging features that can help to differentiate between pancreatic cancer and focal chronic pancreatitis.