The Therapeutic Efficacy of 18F-FDG Combined With 18F-FAPI PET/MR in Neoadjuvant Therapy for Gastric Cancer

NCT06327386 | Recruiting

• 1 other identifier: 202434
• Study Type: observational
• Target: 32
• Locations: 1 country
• Sites: 1

Brief Summary

Gastric cancer is the fifth most common cancer worldwide and the third leading cause of cancer-related deaths. Although surgical treatment can benefit the survival of the vast majority of patients, currently only early gastric cancer patients can be cured directly through endoscopic resection or surgery alone. Neoadjuvant therapy reduces tumor volume and improves tumor response rate through preoperative radiotherapy and chemotherapy, thereby increasing R0 resection rate and improving overall survival, without increasing postoperative complications and mortality. Timely imaging re staging during neoadjuvant therapy can allow patients to enter the surgical stage earlier, thereby reducing their preoperative burden. According to the different stages of neoadjuvant therapy, clinical staging can be divided into baseline stage (cBSstage) and clinical rest stage (cReStage) after neoadjuvant therapy. At present, the conventional imaging methods for diagnosing cBStage in gastric cancer include CT, endoscopic ultrasonography (EUS), and MRI. The NCCN guidelines recommend CT for cBStage, with a diagnostic accuracy of 77.1% to 88.9%. Similarly, EUS and MRI were also used for cBStage, with accuracy rates of 65.0% to 92.1% and 71.4% to 82.6%, respectively. The application of diffusion-weighted imaging (DWI) has improved the accuracy of MRI diagnosis of cBStage to 93%. However, due to the destruction of the gastric wall structure by neoadjuvant therapy, accurate imaging re staging is difficult. Currently, accurate tumor regression grading can only be obtained through surgical resection of pathological specimens. For cReT after neoadjuvant therapy, the diagnostic accuracy of EUS is only 63% (T2: 44%, T3: 68%, T4: 90%). Due to the presence of chronic inflammatory reactions, such as tumor cell apoptosis, necrosis, fibrosis, etc., in both the tumor and the critical normal gastric wall after neoadjuvant therapy, imaging cannot accurately identify the level of gastric wall, leading to the current low value of CT for cReT. Meanwhile, due to the fact that the pathological reactions of lymph nodes after neoadjuvant therapy are mainly subacute inflammatory reactions accompanied by scar tissue formation, and not all lymph node volumes that experience these pathological reactions will rapidly decrease, the accuracy of CT diagnosis of cReN is only 44%, while the sensitivity and specificity of EUS diagnosis of cReN are 50% and 56%, respectively. In addition, positron emission tomography (PET) can reflect the abnormal metabolism, protein synthesis, DNA repair, and cell proliferation of tumors at the molecular level, providing important information in tumor grading diagnosis, prognosis evaluation, treatment decision-making, and efficacy monitoring. The conventional positron tracer 18F-FDG can reflect the glucose metabolism ability of different tissues, while most types of malignant tumors exhibit high metabolism. Therefore, 18F-FDG can be used for the diagnosis, staging, and treatment monitoring of cancer. However, in gastric cancer patients, 18F-FDG has certain limitations, including 1) interference with physiological or inflammatory uptake of the gastric wall; 2) Low uptake of 18F-FDG is present in signet ring cell carcinoma, mucinous adenocarcinoma, or other poorly differentiated cancers with high mucus content; 3) There are cases of false positive FDG after immunotherapy. In the study of SUV changes in the tumor area before and after treatment, it was found that patients with postoperative pathological regression grades 1-5 Δ SUVs are between 0-70%. Tumor associated fibroblasts are closely related to tumor growth, invasion, and distant metastasis, and their activation requires the involvement of fibroblast activation protein (FAP). Therefore, radiolabeled fibroblast activation protein inhibitor (FAPI) can achieve in vivo FAP targeted tracing and quantification by specifically binding to FAP. Currently, a large number of studies have shown that 18F-FAPI is superior to 18F-FDG in the staging and re staging of gastric cancer. Furthermore, prospective studies have shown a certain relationship between tumor regression grade (TRG) and 18F-FAPI rate of change parameters (SUVmax, SUVavg, SUVR). Therefore, in the early stage of this study, 18F-FAPI combined with 18F-FDG PET/MRI imaging was used to evaluate the efficacy of neoadjuvant therapy for gastric cancer, preoperative assessment of tumor regression grade after treatment, and re staging to guide the development of further clinical treatment plans.

Conditions

Cancer

Outcome Measures

Primary Outcomes (1)

• 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 Outcomes (3)

• expression of FAP

  completed within one week after surgery

• expression of GLUT1

  completed within one week after surgery

• SUV

  Completed within one week after PET examination

Study Arms (1)

After neoadjuvant therapy for gastric cancer

* Diagnosed primary gastric adenocarcinoma patients (cT2N+non-surgical treatment, cT3NanyMany and above staging) * Staging of MRI enhanced examination before neoadjuvant therapy * Restaging of preoperative 18F-FAPI and 18F-FDG PET/MRI examination * Postoperative resection was performed after neoadjuvant therapy, with postoperative pathology, regression grading, and related immunohistochemistry * Patient age ≥ 18 years old * The patient voluntarily participates and signs an informed consent form.

Diagnostic Test: 18F-FAPI#18F-FDG

Interventions

18F-FAPI#18F-FDG DIAGNOSTIC_TEST

FAPI and FDG combined with PET/MR imaging in patients with gastric cancer after neoadjuvant therapy

After neoadjuvant therapy for gastric cancer

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

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

You may qualify if:

• Diagnosed primary gastric adenocarcinoma patients (cT2N+non-surgical treatment, cT3NanyMany and above staging)
• Staging of MRI enhanced examination before neoadjuvant therapy
• Restaging of preoperative 18F-FAPI and 18F-FDG PET/MRI examination
• Postoperative resection was performed after neoadjuvant therapy, with postoperative pathology, regression grading, and related immunohistochemistry
• Patient age ≥ 18 years old
• The patient voluntarily participates and signs an informed consent form.

You may not qualify if:

• Severe comorbidities may interfere with treatment or affect disease-specific health-related quality of life
• Drug requirements that interfere with the research protocol
• Pregnant or lactating male subjects who are expected to conceive or cause their spouse to conceive during the planned trial period
• The imaging quality is poor and cannot be used for diagnosis and evaluation.

Sponsors & Collaborators

• Daping Hospital and the Research Institute of Surgery of the Third Military Medical University: lead

Study Sites (1)

Department of Nuclear Medicine, Daping Hospital of Army Medical University

Chongqing, Chongqing Municipality, 400010, China

RECRUITING

Related Publications (1)

• Yoshikawa T, Tanabe K, Nishikawa K, Ito Y, Matsui T, Kimura Y, Hasegawa S, Aoyama T, Hayashi T, Morita S, Miyashita Y, Tsuburaya A, Sakamoto J. Accuracy of CT staging of locally advanced gastric cancer after neoadjuvant chemotherapy: cohort evaluation within a randomized phase II study. Ann Surg Oncol. 2014 Jun;21 Suppl 3:S385-9. doi: 10.1245/s10434-014-3615-8. Epub 2014 Mar 5.

  PMID: 24595801 RESULT

Biospecimen

Retention: SAMPLES WITH DNA

histopathological findings obtained from biopsy or resected surgical specimens

MeSH Terms

Conditions

Neoplasms

Central Study Contacts

Xiao Chen, Ph.D

CONTACT

+8615922970174; xiaochen229@foxmail.com

Study Design

• Study Type: observational
• Observational Model: CASE ONLY
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director of Nuclear Medicine Department

Study Record Dates

• First Submitted: March 17, 2024
• First Posted: March 25, 2024
• Study Start: January 1, 2024
• Primary Completion: January 1, 2026
• Study Completion: January 1, 2026
• Last Updated: August 14, 2024

Record last verified: 2024-08

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)