The goal of this clinical trial is to evaluate the diagnostic value of CAIX protein specific probe 68Ga-C1 in PET/CT imaging in clear cell renal cell carcinoma patients. It will also learn about the safety, tolerability and radiation dosimetry of 68Ga-C1.

Researchers will compare the diagnostic value of 68Ga-C1 PET/CT and 18F-FDG PET/CT in Chinese patients with indeterminate renal masses or confirmed clear cell renal cell carcinoma.

Carbonic anhydrase IX (CAIX) is a transmembrane protein which is highly expressed in approximately 95% of clear cell renal cell carcinomas, and it is closely related to tumor progression, patients prognosis and treatment response. Here, we developed a CAIX specific small molecule probe 68Ga-C1, which has shown a good diagnostic accuracy in PET/CT imaging in our preclinical mouse model of clear cell renal cell carcinoma. This enables high-contrast imaging of clear cell renal carcinoma, providing a new imaging method for the precise diagnosis of clear cell renal carcinoma. In this clinical trail, we will compare the diagnostic value of 68Ga-C1 PET/CT and 18F-FDG PET/CT in Chinese patients with indeterminate renal masses or confirmed clear cell renal cell carcinoma.

Inclusion Criteria:

1. Signed written informed consent；
2. Age ≥18；
3. Patients with confirmed or suspected clear cell renal cell carcinoma;
4. Expected survival ≥6 months.

Exclusion Criteria:

1. Renal mass is known to be a metastasis of another primary tumor;
2. Have other malignancies that require treatment;
3. Have received chemotherapy, radiotherapy, or immunotherapy within 4 weeks;
4. Renal insufficiency with glomerular filtration rate (GFR) ≤ 60 mL/min/1.73 m²;
5. Pregnant and lactating women or female patients plan to become pregnant within 6 months;
6. Uncontrolled psychiatric disorders;
7. Vulnerable population (e.g., being in detention) or have a serious non-malignant disease (e.g., infectious disease, autoimmune disease, or metabolic disease).