PSMA is highly expressed on the cell surface of the microvasculature of several solid tumors, including clear cell renal cell carcinoma (ccRCC). This makes it a potentially imaging target for the detection of ccRCC. This pilot study was designed to evaluate the diagnostic performance of 68Ga-P16-093, a novel radiopharmaceutical targeting PSMA, which was compared with 18F-FDG PET/CT in the same group of ccRCC patients.

Renal cell carcinoma (RCC) is the most common solid tumor within the kidney and accounts for approximately 3% of all malignancies in the world. Clear cell RCC (ccRCC) is the most common subtype and accounts for the majority of kidney cancer-related deaths. Importantly, pro-angiogenic factors (VEGF, PDGF) are strongly upregulated in clear cell RCC, leading to high vascularized tumors. Prostate-specific membrane antigen (PSMA), as known as folate hydrolase I or glutamate carboxypeptidase II, is overexpressed on the cells of prostatic adenocarcinoma. However, PSMA is also expressed by tumor cells or neovascular endothelial cells of various solid neoplasms, such as renal cell carcinoma. Therefore, PSMA may be an ideal target for the diagnosis of ccRCC. 68Ga-P16-093, a novel radiopharmaceutical targeting PSMA, with the urea fragment of a conjugate that employs the HBED-CC chelator for labeling with 68Ga(III). The HBED-based chelating ligand binds the 68Ga3+ ion with high affinity in a pseudo-octahedral N2O4 coordination sphere by its two phenolate O, two amino-acetate carboxylate O, and two amino N donor atoms. This pilot study was designed to evaluate the diagnostic performance of 68Ga-P16-093 in the same group of ccRCC patients, compared with 18F-FDG PET/CT.

Inclusion Criteria:

• patients with confirmed or suspected clear cell Renal cell carcinoma;
• 68Ga-P16-093 18F-FDG PET/CT within a week;
• signed written consent.

Exclusion Criteria:

• pregnancy;
• breastfeeding;
• known allergy against PSMA;
• any medical condition that in the opinion of the investigator may significantly interfere with study compliance.