PET/MR Evaluation of Regression Grading After Neoadjuvant Therapy for Rectal Cancer

Research Focused on Developing and Assessing a Non-intrusive Diagnostic Approach for Grading Tumor Regression Post-neoadjuvant Treatment in Rectal Cancer, Utilizing 18F-FAPI in Conjunction With FDG PET/MR Imaging.

This project aims to evaluate the role of 18F-FAPI combined with 18F-FDG PET/MRI imaging in quantitatively and accurately evaluating the grading of rectal cancer after SCRT neoadjuvant therapy in patients with advanced rectal cancer as the research object, with postoperative histopathological analysis as the reference index, and to assess the ability of patients to achieve pCR. A diagnostic model and evaluation system will also be constructed.

Study Overview

• Status: Recruiting
• Conditions: Rectal Cancer
• Intervention / Treatment: Diagnostic test: 18F-FAPI，18F-FDG

Detailed Description

1. Correlation analysis between the expression levels of FAP and GLUT1 and the degree of tumor regression in rectal cancer

   The study focuses on patients with advanced rectal cancer treated with SCRT neoadjuvant therapy, and conducts immunohistochemical staining of FAP and GLUT1 (glucose transporter 1) on postoperative specimens to evaluate histopathological changes related to the degree of rectal cancer tumor regression. The expression levels of FAP and GLUT1 and the grading of tumor regression are quantitatively analyzed, and their correlation is analyzed to explore the correlation between the expression levels of FAP and GLUT1 in the lesions of neoadjuvant therapy patients and the degree of tumor regression.

2. Construction and validation of a diagnostic model for the degree of tumor regression in rectal cancer after neoadjuvant therapy using 18F-FAPI combined with 18F-FDG PET/MRI imaging

   The patient underwent preoperative 18F-FAPI and 18F-FDG PET/MRI imaging, followed by immunohistochemical staining of FAP and GLUT1 on postoperative specimens and evaluation of histopathological changes related to the degree of rectal cancer tumor regression. The patient's uptake of 18F-FAPI and 18F-FDG (SUVmax, SUVmean, SUVpeak, FAPI metabolic volume, MTV, TBR, TLG), expression levels of FAP and GLUT1, and degree of tumor regression were quantitatively analyzed, and the correlation between the patient's uptake of 18F-FAPI and 18F-FDG and the degree of tumor regression was explored. A graded diagnostic model and evaluation system were constructed to verify their effectiveness.

3. Comparison of the efficacy of PET/MR-TRG and MR-TRG in assessing pTRG after neoadjuvant therapy for rectal cancer

Compare the constructed PET/MR tumor regression grading diagnostic model with the commonly used clinical imaging diagnostic method MRI in evaluating the efficacy, pTRG, and pCR of neoadjuvant therapy for rectal cancer.

• Study Type: Observational
• Enrollment (Estimated): 32

Contacts and Locations

• Study Contact: Name: Xiao Chen, Ph.D; Phone Number: +8615922970174; Email: xiaochen229@foxmail.com

Study Locations

• China
  • Chongqing, China
    • Recruiting
    • Department of Nuclear Medicine, Daping Hospital of Army Medical University
    • Contact: Xiao Chen, Ph.D; Phone Number: +8615922970174; Email: xiaochen229@foxmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

The subjects the investigators selected are adults who are not restricted by gender.

Description

Inclusion Criteria:

• Pathologically confirmed as rectal adenocarcinoma, with baseline clinical staging of T3~4 and/or N+;
• No distant metastasis;
• Not receiving chemotherapy or any other anti-tumor treatment before enrollment;
• Has not received immunotherapy before enrollment and is able to adhere to the protocol during the study period (neoadjuvant therapy of short-term radiotherapy sequential chemotherapy combined with immunotherapy);
• After neoadjuvant therapy, 18F-FAPI and 18F-FDG PET/MRI imaging were performed within 7 days before surgery, and the two scans were collected over two days;
• Patient age ≥ 18 years old

Exclusion Criteria:

• Pregnant or lactating patients;
• Patients with severe heart disease in clinical practice;
• Organ transplantation requires immunosuppressive therapy and long-term use of hormone therapy;
• Patients with autoimmune diseases;
• Serious uncontrolled recurrent infections or other serious uncontrolled comorbidities;
• The imaging quality is poor and cannot be used for diagnosis and evaluation;
• Fasting blood glucose levels are higher than 11.1 mmol/L;
• Patients with contraindications for MRI examination.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

After neoadjuvant therapy for rectal cancer; (1) Pathologically confirmed as rectal adenocarcinoma, with baseline clinical staging of T3~4 and/or N+; (2) No distant metastasis; (3) Not receiving chemotherapy or any other anti-tumor treatment before enrollment; (4) Has not received immunotherapy before enrollment and is able to adhere to the protocol during the study period (neoadjuvant therapy of short-term radiotherapy sequential chemotherapy combined with immunotherapy); (5) After neoadjuvant therapy, 18F-FAPI and 18F-FDG PET/MRI imaging were performed within 7 days before surgery, and the two scans were collected over two days; (6) Patient age ≥ 18 years old; (7) The patient voluntarily participates and signs an informed consent form.

Diagnostic test: 18F-FAPI，18F-FDG; FAPI and FDG combined with PET/MR imaging in patients with rectal cancer after neoadjuvant therapy

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluation efficacy of tumor regression level	The sensitivity, specificity, positive predictive value (PPV), negative predictive value	Completed within half year after end of the study

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
SUV	Standardized uptake value (SUV) of 18F-FDG and 18F-FAPI for each target lesion of subject or suspected primary tumor or/and metastasis.	Completed within one week after PET examination
expression of FAP	Immunohistochemical evaluation of the expression of FAP in postoperative tumor tissue	completed within one week after surgery
expression of GLUT1	Immunohistochemical evaluation of the expression of GLUT1 in postoperative tumor tissue	completed within one week after surgery

Collaborators and Investigators

• Sponsor: Xiao Chen

Publications and helpful links

General Publications

• Wang Y, Shen L, Wan J, Zhang H, Wu R, Wang J, Wang Y, Xu Y, Cai S, Zhang Z, Xia F. Neoadjuvant chemoradiotherapy combined with immunotherapy for locally advanced rectal cancer: A new era for anal preservation. Front Immunol. 2022 Dec 8;13:1067036. doi: 10.3389/fimmu.2022.1067036. eCollection 2022.

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2024
• Primary Completion (Estimated): December 31, 2025
• Study Completion (Estimated): December 31, 2025

Study Registration Dates

• First Submitted: March 5, 2024
• First Submitted That Met QC Criteria: March 12, 2024
• First Posted (Actual): March 19, 2024

Study Record Updates

• Last Update Posted (Actual): March 19, 2024
• Last Update Submitted That Met QC Criteria: March 12, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Keywords: Rectal cancer; Immunotherapy; PET/MRI; 18F-FDG; Efficacy evaluation; 18F-FAPI; New assistance
• Additional Relevant MeSH Terms: Digestive System Diseases; Neoplasms; Neoplasms by Site; Gastrointestinal Neoplasms; Digestive System Neoplasms; Gastrointestinal Diseases; Intestinal Diseases; Intestinal Neoplasms; Rectal Diseases; Colorectal Neoplasms; Rectal Neoplasms; Molecular Mechanisms of Pharmacological Action; Radiopharmaceuticals; Fluorodeoxyglucose F18
• Other Study ID Numbers: 202435

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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