Collagen-binding probe PET/MR for distinguishing fibrotic from inflammatory strictures in Crohn’s disease
摘要
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 methodsPatients 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.
ResultsFive 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).
Conclusion68Ga-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 registrationClinicalTrials.gov, NCT06252493. Date of first enrollment: 19 December 2023. Registered: 2 February 2024 (retrospectively registered).