Gastrointestinal - Learning Modules - CTisus.com CT Scanning

Pitfalls and Pearls in the CT Diagnosis of Pancreatic Cancer

Elliot K. Fishman MD

Does the Pancreas MDC have an impact on patient care and management?

“The single-day pancreatic multidisciplinary clinic provided a comprehensive and coordinated evaluation of patients that led to changes in therapeutic recommendations in close to one-quarter of patients.”
Evaluating the impact of a single-day multidisciplinary clinic on the management of pancreatic cancer.
Pawlik TM, Laheru D, Hruban RH, Coleman J, Wolfgang CL, Campbell K, Ali S, Fishman EK, Schulick RD, Herman JM
Ann Surg Oncol 2008 Aug; 15(8):2078-80

A classic publication summarizes some of our Pancreatic MDC results and impact on patients.

“Outcomes trended toward superior survival for MDC vs. non-MDC patients, and almost 30% of patients had a change in diagnosis. Adjusted for home region, MDC patients were more likely retained, suggesting higher patient satisfaction. Total costs per patient were lower for MDC patients, even with higher retention. Outpatient costs were higher for MDC, suggesting that greater outpatient engagement in MDCs supplant more costly inpatient encounters. Because quality is superior with lower costs, these data suggest multidisciplinary models offer higher-value care.”
Multidisciplinary Oncology Clinics Deliver Higher Value Care.
Elnahal SM, Rosati LM, Moningi S, Hodgin M, Laheru DA, Fishman EK, Weiss MJ, Pawlik TM, Wolfgang CL, Herman JM
Int J Radiat Oncol Biol Phys. 2016 Oct 1;96(2S):S133

From these conferences we have recognized that there are a series of errors that impact on the diagnosis of pancreatic cancer. Many of these errors and pitfalls are avoidable and this exhibit will focus on these pitfalls and provide recommendations on how to avoid them. With a limit of 35 slides we are obviously limited on the number of examples we can provide.

Pitfalls and Pearls in the CT Diagnosis of Pancreatic Cancer: Lessons Learned from a Weekly Multidisciplinary Conference to Improve Diagnostic Accuracy

Pitfalls and Pearls in the CT Diagnosis of Pancreatic Cancer: Lessons Learned from a Weekly Multidisciplinary Conference to Improve Diagnostic Accuracy

CT of the Pancreas: Mistakes in Diagnosis

False Positive studies
- Autoimmune pancreatitis
- Groove pancreatitis
- Chronic pancreatitis
- Focal steatosis in the gland (usually HOP)
- Stent in place in CBD
- Failure to recognize normal gland anatomy
- Vascular processes can simulate a pancreatic mass (pseudolesion)

Autoimmune Pancreatitis: A Great Mimicker

Diffuse glandular enlargement with loss of lobular texture (“featureless gland)
Homogeneously iso- or hypoattenuating parenchyma with a nondilated or diffusely narrowed pancreatic duct
“halo” around gland is not uncommon

Groove Pancreatitis Simulates a Pancreatic Mass

Groove Pancreatitis Simulates a Pancreatic Tumor with Dilated CBD

CT of the Pancreas: Mistakes in Diagnosis

False Negative studies
- Small pancreatic mass not recognized
- Absence of secondary signs like dilated PD or CBD
- Acute pancreatitis or chronic pancreatitis masks underlying tumor
- Poor scan protocol (single phase, poor injection, poor timing)

Small Pancreatic Cancer with Dilated Pancreatic Duct

Neuroendocrine Tumor HOP Seen Only On Arterial Phase

Patient Referred for a Pancreatic Tail Mass Had Varices but no Pancreatic Mass

Subtle Cancer Body of the Pancreas

Adenocarcinoma Pancreas with Subtle Arterial Involvement

CT of the Pancreas: Mistakes in Diagnosis and Staging

Misdiagnosis as to the etiology of the pancreatic mass. The mass was not an adenocarcinoma but was;
- Cystadenoma of the pancreas
- Neuroendocrine tumor of the pancreas
- Metastatic disease to the pancreas
- Primary biliary tumor
- Peripancreatic tumors including duodenal GIST tumor and duodenal adenocarcinoma, lymphoma, metastatic nodes from colon cancer and biliary tumors

Metastatic Breast Cancer to the Pancreas (dx 2 yrs ago)

Breast Cancer Metastatic to the Pancreas Invades Portal Vein

Metastatic Melanoma to Duodenum Simulates a Pancreatic Mass with Dilated CBD

Duodenal Carcinoid Tumor Simulates a Pancreatic PET

Duodenal Adenocarcinoma with Double Duct Sign

Duodenal Adenocarcinoma Simulates a Pancreatic Mass

Duodenal GIST Tumor Simulates a Pancreatic Mass. Key is lack of CBD or PD Obstruction and Epicenter of Lesion

GIST Tumor Duodenum Simulates Pancreatic Mass

CT of the Pancreas: Mistakes in Diagnosis and Staging

Staging of the patients tumor was incorrect with errors commonly including;
- False positive or false negative liver metastases
- Incorrect staging of vascular involvement including the celiac, SMA, hepatic artery and GDA
- Incorrect staging of vascular involvement of the portal vein, SMV and/or splenic vein
- Presence of carcinomatosis including implants on the omentum, mesentery and bowel
- Missed presence of second pancreatic primary resulting in change of surgical plan

“Although these routine CT examinations may be diagnostic for pancreatic adenocarcinoma, they are inadequate for disease extent assessment given the lack of optimal multi-phasic enhancement and use of thicker slice selection. These factors limit the ability to generate high quality reformatted images and 3D reconstructions that are often necessary for accurate staging. It is therefore essential that these patients undergo MDCT angiogram using a dedicated pancreatic protocol.”
Pancreatic Ductal Adenocarcinoma Radiology Reporting Template: Consensus Statement of the Society of Abdominal Radiology (SAR), and the American Pancreatic Association (APA)
Al-Hawary MH, Francis IR, Chari ST, Fishman EK et al.
Radiology 2014;270:248-260

Pancreatic Scan Protocol: Data Acquisition

The success of a pancreatic cancer study is dependent on the CT scan protocol used. Some of the key factors for the successful exam include;
- Venous access to allow for injection rate of 5 cc/sec of non-ionic contrast
- Dual phase acquisition at 30 seconds (arterial) and 60 seconds (venous)
- Reconstruction of data using thin section CT (.75 mm reconstruction at .5 mm) multiplanar imaging (coronal and sagittal imaging) and 3D post processing (volume rendering and MIP)

Conclusion

The review of complex cases in a multidisciplinary setting provides insights into scan interpretation and results in an improved Radiologist experience
Many pitfalls in pancreatic imaging are predictable and a careful interpretation strategy is needed to avoid them.
Radiology case conferences are a great way of sharing misdiagnosis and pitfalls in diagnosis.