Prostate specific membrane antigen (PSMA) is a type II transmembrane protein and acts as a glutamate carboxypeptidase enzyme. It is first described in prostate cancer cell lines and later identified in various tissues, include salivary gland. This pilot study was designed to evaluate the diagnostic performance of 68Ga-P16-093 in primary sjogren's syndrome patients.

Primary sjogren's syndrome (pSS) is a systemic autoimmune disease mainly presented hyperglobulinemia and exocrine gland involvement,and lack of diagnostic gold standard.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 various solid organs , such as salivary gland,which is often observed damage in primary Sjogren's syndrome patients.Therefore, PSMA may be an ideal target for evaluating salivary gland injury.

Inclusion Criteria:

• pathological diagnosis confirmed by operation or biopsy.
• Obtain written informed consent and accepted follow-up.

Exclusion Criteria:

• Pregnant, lactating women or having parenting plans during the study
• Head and neck radiotherapy history ;
• Active hepatitis C infection (PCR positive), include immunodeficiency syndrome, sarcoidosis, amyloidosis, graft versus host disease, IgG4 related diseases.
• Other situaition researchers considered it was not appropriate to participate in trials.