Using PSMA and FAPI PET scans to map salivary gland function and inflammation in Sjögren's syndrome

Exploring the Novel Value of PSMA PET in Sjögren's Syndrome: Integrated Analysis With Established FAPI PET Imaging

This study will test whether combining PSMA and FAPI PET scans can better show salivary gland function and inflammation in people with primary Sjögren's syndrome.

Quick facts

• Phase: NA
• Study type: Interventional
• Enrollment: 60 (estimated)
• Ages: 18 Years to 80 Years
• Sex: All
• Sponsor: Peking Union Medical College Hospital (other)
• Locations: 1 site (Beijing)
• Trial ID: NCT07324733 on ClinicalTrials.gov

What this trial studies

This single-center study will perform paired 68Ga-PSMA PET/CT and 68Ga-FAPI PET/CT scans in adults with primary Sjögren's syndrome and a comparison group of patients scheduled for FAPI imaging for solid tumors. PSMA uptake is expected to reflect salivary acinar cell function while FAPI uptake highlights activated fibroblasts and fibroblast-driven remodeling; the investigators will compare tracer signals within the same glands. They will derive a combined PSMA/FAPI Index to map a function–inflammation spectrum and examine correlations between the two tracers and clinical disease features. Imaging results will be analyzed to explore whether this noninvasive paired biomarker can improve staging and monitoring of pSS.

Who should consider this trial

Good fit: Adults aged 18–80 who meet the 2016 ACR–EULAR criteria for primary Sjögren's syndrome (or patients with a solid tumor already scheduled for FAPI PET) and who are not using hormones or biological agents are ideal candidates.

Not a fit: Patients with overlapping connective tissue diseases, current use of hormones or biologic therapies, pregnancy or lactation, or other contraindications to PET/CT are unlikely to receive benefit from participation.

Why it matters

Potential benefit: If successful, this approach could provide a noninvasive imaging marker to more precisely stage disease, monitor progression, and help guide treatment decisions in primary Sjögren's syndrome.

How similar studies have performed: Prior imaging work has shown PSMA relates to salivary acinar cells and FAPI to fibroblast activity, but applying a paired PSMA/FAPI index in pSS is a novel and largely untested approach.

Eligibility criteria

Inclusion Criteria:

* Age 18-80 years;
* Fulfillment of the 2016 ACR-EULAR Classification Criteria for pSS at enrollment. OR diagnosis of a solid tumor scheduled for FAPI PET imaging

Exclusion Criteria:

* Combined with tumors or other connective tissue diseases (for SS group);
* Patients who are currently using hormones/biological agents (for both groups)；
* Pregnancy or lactation

Where this trial is running

Beijing

• Peking Union Medical College Hospital — Beijing, China (RECRUITING)

Study contacts

• Study coordinator: Zhaohui Zhu, MD

Conditions: Primary Sjögren Syndrome, PET