Lupus Nephritis Revealed by FAPI PET/CT

Area of Science:

• Nuclear Medicine
• Radiochemistry
• Oncology

Background:

• Systemic lupus erythematosus (SLE) is a chronic autoimmune disease.
• Lupus nephritis (LN) is a common and serious complication of SLE.
• Fibroblast activation protein (FAP) is implicated in inflammation and cancer.

Purpose of the Study:

• To describe the imaging characteristics of lupus nephritis using 68Ga-FAPI-04 PET/CT.
• To report the incidental finding of a carotid body tumor on 68Ga-FAPI-04 PET/CT.
• To evaluate the utility of 68Ga-FAPI-04 PET/CT in a patient with SLE.

Main Methods:

• A 38-year-old woman with SLE underwent a 68Ga-FAPI-04 PET/CT scan.
• Imaging analysis focused on kidney parenchyma and identified incidental findings.

Main Results:

• Diffuse increased uptake in both kidney parenchyma was observed, consistent with lupus nephritis.
• An incidental carotid body tumor with increased 68Ga-FAPI-04 uptake was detected.
• The scan successfully visualized both the autoimmune kidney disease and an incidental tumor.

Conclusions:

• 68Ga-FAPI-04 PET/CT can visualize lupus nephritis.
• FAPI PET/CT may incidentally detect other pathologies, such as carotid body tumors.
• This case demonstrates the potential of FAPI PET/CT in evaluating patients with systemic autoimmune diseases.