3rd Annual BMRP Investigator Meeting - Abstract
Testing the Homogeneity of the Stenotic/Stricturing Phenotype in Crohn’s Disease Utilizing PET/CT Imaging
Philip M. Ginsburg1,a, Elizabeth A. Montgomery2,b, Richard L. Wahl3,b, Heather Jacene3,b and Theodore M. Bayless1
1Harvey M. and Lyn P. Meyerhoff Inflammatory Bowel Disease Center, Division of Gastroenterology, Department of Medicine, 2Division of Gastrointestinal Pathology, Department of Pathology, and 3Division of Nuclear Medicine/PET, Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine (Baltimore, Maryland, U.S.A.)
Background: The “Stenotic/Stricturing” phenotype is associated with obstructive symptoms in approximately half of ileal Crohn’s disease (CD) patients and is more frequent with NOD2/CARD 15 mutations, however, this phenotype may be heterogeneous. Surgery is appropriate for lumen narrowing due to fixed fibrosis, but medical therapy including infliximab could be considered when inflammation is a major factor. On pathologic review of 20 consecutive patients operated for small bowel obstructive problems, only four had marked scarring. Five had predominant inflammation with muscle hypertrophy. We hypothesize that PET/CT may differentiate between stenosis due to fibrosis versus inflammation.
Methods: 20 CD patients undergoing surgery for obstruction have a pre-operative PET/CT scan where the intensity of metabolic activity is quantified. Resected specimens are graded for inflammation, muscle hypertrophy, and fibrosis.
Results: Patients who have completed the study had well defined areas of localized radioisotope uptake in the right lower quadrant, which fused to the terminal ileum on the CT scan. The intensity of uptake measured by standardized uptake variable (SUV) was 10.8 for a patient with severe inflammatory stenosis with only minimal (10%) fibrosis in the resected ileum. Conversely, SUV was 6.5 for a patient with marked fibrotic narrowing involving 100% of the muscularis mucosa with only minimal acute and moderate chronic inflammation. Muscle hypertrophy is thus far universal.
Conclusions: Initial data from this study suggest: 1) a good correlation between PET/CT and histopathologic findings; and 2) that this methodology can distinguish inflammatory stenosis from fibrotic stenosis.
aPrincipal Investigator
bDid not review this abstract due to blinding