The detection of prostate cancer lesions by PET imaging of the prostate-specific membrane antigen (PSMA) has gained highest clinical impact during the last years. 68Ga-labelled Glu-urea-Lys(Ahx)-HBED-CC ([68Ga]Ga-PSMA-HBED-CC) represents a successful novel PSMA inhibitor radiotracer which has recently demonstrated its suitability in individual first-in-man studies. Early detection of metastases or recurrent prostate cancer (PC) lesions is of utmost clinical relevance in terms of clinical staging, prognosis and therapy management . The high clinical impact of targeting the prostate-specific membrane antigen (PSMA) was recently demonstrated in a series of first-in-man examinations with either 68Ga- [3–5] or 123I-labelled  PSMA inhibitors. PSMA is a membrane-type zinc protease, also called glutamate carboxypeptidase II (GCPII), which is expressed by nearly all prostate cancers. Enhanced expression levels were found in poorly differentiated, metastatic and hormone-refractory carcinomas . Since urea-based inhibitors of PSMA clear rapidly from the circulation and since only low levels of physiological PSMA expression were detected in a few organs like the brain, kidney, salivary gland and small intestine PSMA represents an ideal biological target for high quality PET imaging of prostate cancer .
Image Ga68 PSMA PET scan: Courtesy Sheba medical center
for more information please read “Comparison of PET imaging with a 68Ga-labelled PSMA