Exploring the Application Value of PET Molecular Imaging Targeting FAP in Oral Squamous Cell Carcinoma

Positron emission tomography (PET) molecular imaging provides a valuable method for the diagnosis, differential diagnosis and staging of various tumors. Cancer associated fibroblasts (CAFs) are the main components of tumor stroma, which are involved in tumor cell proliferation, invasion, metastasis and tumor angiogenesis, and play an important role in the occurrence and development of tumors. Fibroblast activation protein (FAP) is the most potential specific molecular marker of CAF, which is mainly expressed in stromal fibroblasts of epithelial tumors and is a potential molecular target for tumor diagnosis and treatment. Oral cancer is the most common type of malignant head and neck cancer, seriously endangering human health. Accurate delineation of the primary tumor, detection of regional nodal metastases, distant metastases and second primary tumors are important for determining the therapeutic strategy and prognosis of oral cancer. Currently, the molecular imaging agent most commonly used in clinical practice for oral cancer is 18F-fluoro-deoxy-glucose (18F-FDG). However, 18F-FDG exhibits some shortages. Inflammatory lesions and the surrounding normal tissue such as brain, tonsils and salivary glands show high uptake of 18F-FDG, often affecting the judgment of lesions. In this prospective study, the investigators will use integrated PET/CT with the agent 68Ga-FAPI and conventional imaging agent 18F-FDG to explore the application value of FAP-targeted molecular imaging in the diagnosis and staging for oral cancer.

Inclusion criteria were as follows: (i) adult patients (18 years or older); (ii) pathologically confirmed or highly suspected HNSCC; (iii) clinically suspected recurrence of HNSCC; (iv) underwent paired 18F-FDG and 68Ga-FAPI PET/CT within one week. The exclusion criteria were as follows: (i) received anticancer therapy within 3 months before PET/CT scan; (ii) hyperglycemia (fasting glucose \> 11.1 mmol/L); (iii) patients failing to complete both PET/CT scans; (iv) the final pathological findings showed non-SCC; (v) patients with second primary tumor; (vi) patients with unknown primary tumor.

Eligibility Criteria:
Inclusion Criteria:

1. Volunteered to participate in this study and signed informed consent;
2. Age range from 18 to 70 years;
3. Clinically highly suspected oral cancer and recurrence after treatment, obtaining pathology results and planning surgery;
4. Willing and able to follow schedule visits, treatment plans and laboratory tests;
5. The clinical laboratory general biochemical examination (heart, liver, kidney, blood routine) and other indicators are in the normal range or abnormal without clinical significance.

Exclusion Criteria:

1. Female patients who plan to become pregnant within 6 months, or are pregnant or breastfeeding;
2. Those who are allergic to test drugs, allergic constitution, or allergic to multiple drugs;
3. People with poor general condition, their heart, lung, liver, kidney and other important organ functions cannot tolerate surgery;
4. Before the injection of 18F-FDG, the fasting blood glucose level exceeded 11.0 mmol/L;
5. The weight exceeds 100 kg;
6. Patients with claustrophobia;
7. Those who cannot tolerate lying supine for 15\~30 minutes;
8. Researchers think it is inappropriate to participate in this clinical trial;
9. Those who have participated in clinical trials or are participating in other clinical trials in the past month.