177Lu-DOTA-HYNIC-Lys(Nal)-Urea-Glu: synthesis and assessment of the ability to target the prostate specific membrane antigen

SPECT/CT images have proved the capability of 99m Tc-EDDA/HYNIC-Lys(β-naphthylalanine)-NH-CO-NH-Glu to detect prostate cancer tumors in patients. Considering that theranostics combines the potential of therapeutic and diagnostic radionuclides in the same molecular probe, this research aimed to prepare 177 Lu-DOTA-HYNIC-Lys(β-naphthylalanine)-NH-CO-NH-Glu ( 177 Lu-iPSMA) and evaluate the in vitro and in vivo radiotracer ability to target the PSMA protein overexpressed in prostate cancer cells (LNCaP). 177 Lu-iPSMA, obtained with radiochemical purities of 99%, showed specific in vitro and in vivo recognition for PSMA in prostate cancer cells and high LNCaP-tumor uptake (11 ± 2% ID/g at 24 h). The results obtained warrant further studies to evaluate the therapeutic efficacy of 177 Lu-iPSMA.