Inclusion Criteria:

• Age between 18 and 75 years；
• Diagnosed with MTC and have surgical indication based on preliminary evaluation; the tumor may be newly diagnosed or previously treated;
• Expected survival of at least 12 weeks;
• No major organ dysfunction (heart, lung, liver, kidney and other major organ include), acute or life-threatening status of infection;
• Be willing and able to understand the research content and provide written informed consent/assent for the trial.

Exclusion Criteria:

• Have a history of imaging agent allergies;
• Does not meet the PET-CT scan sedation requirements, or has contraindications for PET-CT examination;
• Be pregnant or breastfeeding, or expecting to conceive or father children within the projected duration of the trial;
• No surgical indication (i.e., no measurable disease, unresectable disease, or significant present of distant metastasis), refusing surgery or 68Ga-TCR-FAPI PET/CT-guided surgery.