Application of PET/MRI in the Evaluation of the Efficacy of Neoadjuvant Therapy for Locally Advanced Rectal Cancer

Overview

This study plans to include LARC patients receiving neoadjuvant therapy at this center, conducting PET/CT and PET/MR examinations before treatment, and PET/MR examinations before surgery after neoadjuvant therapy. The changes in the lesion before and after treatment will be compared to evaluate the efficacy of neoadjuvant therapy, including: the relief situation of the rectal primary lesion ; lymph node metastasis; local infiltration around the tumor; peritoneal and other distant metastases , etc. The pathological relief diagnosed by surgical pathology is the gold standard, and the predictive efficacy of PET/MR will be evaluated, comparing the advantages and disadvantages of 18F-FDG and 68Ga-FAPI PET/MR, and comparing with traditional PET/CT and rectal MRI to explore the value of PET/MRI in predicting the efficacy of neoadjuvant therapy in LARC patients.

Interventions

• Diagnostic test 18F-FDG PET/CT and PET/MR scan, 68Ga-FAPI-04 PET/CT and PET/MR scan
  Patients with Locally Advanced Rectal Cancer underwent 68Ga-FAPI-04 PET/CT and PET/MR scan after injection of 0.02 to 0.04 mCi/Kg×patient weight (Kg). Within 1 week before and after the examination, 18F-FDG PET/CT and PET/MR is completed.

Primary outcome measures

• Diagnostic performance including sensitivity, specificity, accuracy [Time frame: Through study completion, an average of 1 year]

Secondary outcome measures (1)

• TNM stage changed by 68Ga-FAPI-04 PET/CT and PET/MR compared to 18F-FDG PET/CT and PET/MR. [Time frame: Through study completion, an average of 1 year]

Eligibility criteria

Inclusion criteria

• (1) Age 18-75 years old; (2) ECOG score 0-2; (3) Pathologically confirmed as rectal adenocarcinoma; (4) The lower edge of the tumor is within 12cm from the anal edge; (5) Clinically staged as cT3-4N0M0 or cTanyN+M0; (6) Untreated patients who have not received radiotherapy, chemotherapy, and surgery, etc.; (7) Good liver and kidney function, can tolerate radiotherapy and surgery; (8) Patients and their families can understand the research plan, voluntarily participate in this research and sign the informed consent form.

Exclusion criteria

• (1) ECOG score > 2; (2) Patients with multiple primary colorectal cancers; (3) Patients with a history of other malignant tumors within the past 5 years (except for cured basal cell carcinoma, cervical carcinoma in situ, surgically treated localized prostate cancer, or surgically removed breast ductal carcinoma in situ); (4) Patients with intestinal obstruction, intestinal perforation, gastrointestinal bleeding, and other emergencies requiring emergency surgery; (5) Pregnant or lactating women; (6) Patients with a history of severe mental illness, immune diseases, and hormone medication; (7) Patients with contraindications for MRI, PET examination, radiotherapy, immunotherapy, or surgical treatment; (8) Patients who have participated in other clinical studies within the last 3 months; (9) Any other conditions deemed unsuitable for inclusion by the researcher.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Diagnostic

Study locations

China · 1 center

• Peking Union Medical College Hospital — Beijing

Identifiers

NCT: NCT06653452 · PUMCH-NM-LARC-FAPI

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗