Eur J Nucl Med Mol Imaging. 2026 Feb 17. doi: 10.1007/s00259-025-07741-x. Online ahead of print.
ABSTRACT
PURPOSE: To evaluate the feasibility and diagnostic performance of 68Ga-CBP8 PET/MR enterography for noninvasive detection of bowel collagen deposition and differentiation of inflammatory from fibrotic or mixed strictures in Crohn’s disease.
MATERIALS AND METHODS: Patients with stricturing Crohn’s disease scheduled for bowel resection or endoscopic biopsy were prospectively enrolled. PET/MR enterography was performed after intravenous administration of 68Ga-collagen binding probe 8 (68Ga-CBP8). Focal radiotracer uptake was defined as activity exceeding local background and anatomically corresponding to an MR-identified bowel stricture. Surgical and biopsy specimens underwent blinded pathologic evaluation for fibrosis. Descriptive statistics, sensitivity and specificity were calculated to assess diagnostic performance. Differences in SUVmax and SUVmax stricture-to-uninvolved bowel ratio between fibrotic and non-fibrotic segments were evaluated using the Mann-Whitney U test, with p < 0.05 considered statistically significant.
RESULTS: Five patients (4 M, 1 F; median age: 50; IQR: 11) with seven strictured bowel segments (median length: 24 mm; IQR: 14) were included. Five segments (71.4%) demonstrated focal 68Ga-CBP8 uptake and were pathologically confirmed as mixed inflammatory-fibrotic strictures. Two segments (28.6%) showed no significant uptake and were confirmed as strictures devoid of fibrosis. 68Ga-CBP8 PET/MR enterography achieved 100% sensitivity for mixed inflammatory-fibrotic strictures and 100% specificity for non-fibrotic strictures. SUVmax and SUVmax stricture-to-uninvolved bowel ratio were higher in fibrotic than non-fibrotic segments (median SUVmax: 2.29 vs. 1.01; median ratio: 2.36 vs. 0.88), although without statistically significant differences (both p = 0.095).
CONCLUSION: 68Ga-CBP8 PET/MR enterography is a feasible noninvasive technique to assess bowel strictures in Crohn’s disease and may enable differentiation of inflammatory and fibrotic components.
TRIAL REGISTRATION: ClinicalTrials.gov, NCT06252493. Date of first enrollment: 19 December 2023. Registered: 2 February 2024 (retrospectively registered).
PMID:41699282 | DOI:10.1007/s00259-025-07741-x
