Pilot Study Using Secretin and Iodinated Intravenous Contrast and 64-Channel CT in Patients at High Risk for Pancreatic Adenocarcinoma
Pancreatic cancer is the fourth most common cause of cancer death in the US. Because
patients with pancreatic cancer rarely presents with disease specific symptoms until late in
the course of the disease, identifying and developing surveillance strategies for early
detection of asymptomatic pancreatic cancer is critical. EUS and fine needle aspirate (FNA)
are currently the most accurate non-operative methods of establishing the presence or
absence of pancreatic cancer.
The CT findings of pancreatic cancer include an attenuation difference between the
pancreatic mass and the surrounding pancreatic parenchyma, pancreatic ductal dilation and
cutoff, disruption of the normal fatty marbling of the pancreatic parenchyma, rounding of
the inferior margin of the posterior head of the pancreas, atrophy of the proximal gland,
and signs of locally advanced or distant disease. In a case-controlled retrospective review
of pancreatic cancers missed at CT prior to clinical presentation at the Mayo Clinic, Gangi
et al found that CT findings definite or suspicious for pancreatic cancer were present in
50% of scans obtained up to 18 months before the clinical diagnosis of pancreatic cancer.
Pancreatic duct dilation and cutoff were early CT findings indicating tumor presence, and
were associated with near-perfect and substantial interobserver agreement. Consequently,
early pancreatic neoplasms likely result in at least partial occlusion of the duct, leading
to subsequent ductal dilation.
We hypothesize that increased production of the pancreatic juice distends the otherwise
small caliber pancreatic duct, and accentuate the secondary sign of pancreatic duct
obstruction by a small pancreatic mass. The investigators will be able to take advantage of
this physiologic effect of secretin, by obtaining multi-planar scans with isotropic
resolution using a 64-channel CT system.
Secretin is a safe agent that increases pancreatic exocrine secretion. Intravenously
administered secretin increases the pancreatic juice secretion, and magnetic resonance or CT
scan obtained after secretin has been shown to improve visualization of the pancreatic duct.
Day 1: Patient will fast 4 hours prior to the study. 1 L of water is given by mouth as an
oral contrast material 30 minutes prior to the study. After placing an angiocath in the
antecubital fossa, the patient will be placed in a supine position on the CT scanner.
Secretin test dose will be given intravenously (0.2mcg (0.1ml). If no reaction is noted
after one minute, then Secretin will be given intravenously (0.2 mcg/kg IV slowly over one
minute). If an allergic reaction is noted, the patient will not have a CT scan performed as
part of this study protocol, and that participant will be ineligible to participant with
this study. Secretin bolus will be terminated if Systolic BP < 90mm/Hg is not corrected
with IV fluids.
Pre-contrast scan will be obtained with collimation of 0.6 x 64 mm and a pitch of 1.2
through the abdomen under deep inspiration. Images will be reconstructed with 1 mm slice
thickness and 2 mm increment.
Five minutes after administration of the intravenous Secretin, iodinated contrasted
Omnipaque 350 administered at 3-5ml/sec. Post-iodine-contrast scanning will be obtained with
collimation of 0.6 x 64 mm and a pitch of 1.2 through the abdomen with scan delays of 40-
and 70-seconds. Total of 150 ml of intravenous iodinated contrast will be administered at
the rate of 3 - 5 ml/ sec.
For the 3 month (Day 2) and 18 month (Day 3) follow-up CT imaging:
Patient will fast four hours before scan. 1 liter of water given orally 30 minutes prior to
scan. An IV will be placed, and participant will have iodinated contrast (Omnipaque 350)
administered at 3-5ml/sec. Post iodine scanning will be done with collimation of 0.6 x64mm
and a pitch of 1.2 through the abdomen with scan delays of 40 and 70 seconds.
For the optional CT scan for those who have initial positive CT:
This exam is to be done only before endoscopic ultrasound (EUS). Patient will fast four
hours before scan. 1 liter of water given orally 30 minutes prior to scan. An IV will be
placed, and participant will have iodinated contrast (Omnipaque 350) administered at
3-5ml/sec. Post iodine scanning will be done with collimation of 0.6 x64mm and a pitch of
1.2 through the abdomen with scan delays of 40 and 70 seconds.
Subjects will be followed up for 3-5 years to determine if they develop pancreatic cancer.
Allocation: Non-Randomized, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Diagnostic
Number of Subjects With Evidence of Pancreatic Tumor or Any Secondary Findings of Pancreatic Tumor as Shown by CT.
Subjects will receive the secretin test dose just prior to the CT scan. Definitions: Evidence of Pancreatic Tumor (low-attenuation mass), Secondary Findings of Pancreatic Tumor such as dilated pancreatic duct or liver masses suggestive of liver metastases.
Day 1 of study
Naoki Takahashi, M.D.
United States: Food and Drug Administration
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