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

Recruiting
Conditions
Rectal Cancer
Interventions
Diagnostic Test: 18F-FAPI,18F-FDG
Registration Number
NCT06318234
Lead Sponsor
Xiao Chen
Brief Summary

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.

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.

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
32
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 & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Arm && Interventions
GroupInterventionDescription
After neoadjuvant therapy for rectal cancer18F-FAPI,18F-FDG(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.
Primary Outcome Measures
NameTimeMethod
Evaluation efficacy of tumor regression levelCompleted within half year after end of the study

The sensitivity, specificity, positive predictive value (PPV), negative predictive value

Secondary Outcome Measures
NameTimeMethod
expression of GLUT1completed within one week after surgery

Immunohistochemical evaluation of the expression of GLUT1 in postoperative tumor tissue

SUVCompleted within one week after PET examination

Standardized uptake value (SUV) of 18F-FDG and 18F-FAPI for each target lesion of subject or suspected primary tumor or/and metastasis.

expression of FAPcompleted within one week after surgery

Immunohistochemical evaluation of the expression of FAP in postoperative tumor tissue

Trial Locations

Locations (1)

Department of Nuclear Medicine, Daping Hospital of Army Medical University

🇨🇳

Chongqing, China

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