18F-FDG and 68Ga-FAPI PET/CT in Crohn's Disease

A Prospective Study to Evaluate the Inflammation and Fibrosis of Intestinal Stricture in Patients With Crohn's Disease by 18F-FDG and 68Ga-FAPI PET/CT

Intestinal stricture is a complication of Crohn's disease (CD), which is thought to be the result of chronic transmural inflammation combined with a dysregulated wound-healing process. While inflammatory strictures may respond to anti-inflammatory treatment, fibrotic strictures are usually anti-inflammation resistant, requiring further endoscopic balloon dilation or surgical intervention. Therefore, to determinate the inflammatory or fibrotic nature of intestinal stricture is a key step in the treatment of CD. 18F-FDG is a radiotracer reflecting the glucose metabolism of disease and is usually accumulated in inflammatory disease. 68Ga-FAPI is a novel radiotracer that specifically targets fibroblast activation protein (FAP). FAP is a membrane glycoprotein expressed on activated fibroblasts, which are key cells in the process of fibrotic intestinal stricture of CD. In this study, we hypothesis that the inflammatory or fibrotic nature of intestinal stricture can be non-invasively evaluated by 18F-FDG and 68Ga-FAPI PET/CT in patients with CD.

Study Overview

• Status: Unknown
• Conditions: Crohn Disease
• Intervention / Treatment: Diagnostic test: 18F-FDG and 68Ga-FAPI PET/CT

Detailed Description

Patients with intestinal stricture will undergo 18F-FDG and 68Ga-FAPI PET/CT on two consectutive days. The accumulation of 18F-FDG and 68Ga-FAPI at the site of stricture will be determined by standard uptake value (SUV), molecular volume (MV), and total molecular index (TMI). In patients with a planned surgical resection of one or more stricture (s), the image results will be compared with histological findings.

• Study Type: Interventional
• Enrollment (Anticipated): 30
• Phase: Phase 2

Contacts and Locations

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Written informed consent signed
• Crohn's disease patients with proofs of intestine stricture by other modalities, e.g. MRI, CT, ultrasound, and/or endoscopy.

Exclusion Criteria:

• Known hypersensitivity to any of the excipients of 18F-FDG and 68Ga-FAPI.
• If the patients are on metformin, discontinuation of 48 hours is required before 18F-FDG injection to minimize the bowel uptake.
• Pregnant or breast-feeding women.
• Any mental condition rendering the patient unable to understand the nature, scope, and possible consequences of the study, and/or evidence of an uncooperative attitude.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Crohn's disease: patients with intestinal stricture; Patients with intestinal strictures confirmed by other modalities, e.g. CT, MR, ultrasound, and endoscopy, will be recruited in the study.

Diagnostic test: 18F-FDG and 68Ga-FAPI PET/CT; Participants will undergo 18F-FDG (0.12-0.15mCi/kg) and 68Ga-FAPI (3-6mCi) PET/CT on two consecutive days. At least 6 hours of fast is required for 18F-FDG PET scan, while no dietary control is necessary for 68Ga-FAPI PET scan. If the patients are on metformin, discontinuation of 48 hours is required before 18F-FDG injection to minimize the bowel uptake. If the patient is planned for surgical resection of one or more stricture (s), the scans have to be completed within a maximum period of 30 days before the surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
SUVmax of stenotic intestine	The SUVmax of stenotic intestine will be determined on 18F-FDG and 68Ga-FAPI PET scan to reflect the highest extent of inflammation and fibrosis, respectively.	Day 30 after PET scan
MV of stenotic intestine	The MV of stenotic intestine will be determined on 18F-FDG and 68Ga-FAPI PET scan to reflect the involved area of inflammation and fibrosis, respectively.	Day 30 after PET scan
TMI of stenotic intestine	The TMI of stenotic intestine will be determined on 18F-FDG and 68Ga-FAPI PET scan to reflect the overall extent of inflammation and fibrosis, respectively.	Day 30 after PET scan

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Histological findings	In patients with surgical resection of stenotic intestine, the extent of inflammation and fibrosis will be determined.	Day 90 after surgery

Collaborators and Investigators

• Sponsor: Peking Union Medical College Hospital

Study record dates

Study Major Dates

• Study Start (Anticipated): September 1, 2020
• Primary Completion (Anticipated): September 1, 2021
• Study Completion (Anticipated): September 1, 2021

Study Registration Dates

• First Submitted: August 4, 2020
• First Submitted That Met QC Criteria: August 4, 2020
• First Posted (Actual): August 6, 2020

Study Record Updates

• Last Update Posted (Actual): August 7, 2020
• Last Update Submitted That Met QC Criteria: August 5, 2020
• Last Verified: August 1, 2020

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Digestive System Diseases; Gastrointestinal Diseases; Gastroenteritis; Intestinal Diseases; Inflammatory Bowel Diseases; Crohn Disease; Molecular Mechanisms of Pharmacological Action; Radiopharmaceuticals; Fluorodeoxyglucose F18
• Other Study ID Numbers: FAPICD

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No