The goal of this pilot clinical trial is to see the potential application of a CAIX targeted PET. tracer in patients with clear cell renal cell carcinoma. The main question[s] it aims to answer are:

• The biodistribution of the PET tracer
• Whether RCC lesions can be identified by the PET tracer Participants will undergo 68Ga-NY104 PET/CT scan and images will be reviewed by nuclear medicine specialists.

PET/CT imaging of three patients using 68Ga-NY104 for medical reasons will be performed. Patients received an intravenous injection of 68Ga-NY104. Images will be obtained at 0.5 h, 1 h, and 2 h after injection. A comparative 18F-FDG PET/CT scan will also be performed if necessary. The study will be carried out on a time-of-flight PET/CT scanner. SUVmax and SUVmean of normal organs and lesions, as well as tumor-to-background ratios, will be quantitatively assessed using a region-of-interest technique.

Inclusion Criteria:

1. Confirmed or suspected metastatic ccRCC
2. Age ≥ 18 y
3. Written informed consent provided for participation in the trial
4. In the opinion of investigator, willing and able to comply with required study procedures.

Exclusion Criteria:

1. Patients on VEGF TKI treatment < 1 week before 68Ga-NY104 PET/CT. TKI is known to affect girentuximab binding in patients with ccRCC. If patients were on VEGF TKI treatment, such as sunitinib, sorafenib, cabozantinib, pazopanib, or lenvatinib, a washout of one week before 68Ga-NY104 PET/CT is required.
2. Pregnancy or breastfeeding.
3. Severe claustrophobia.

Images and quantitative measures will be available upon on request