Keloid scars are common benign fibroproliferative reticular dermal lesions. Fibroblasts are considered to be the key cellular mediators of fibrogenesis in keloid scars. Thus this prospective study is going to investigate whether 68Ga-FAPI PET/CT may provide evidence for diagnosis and evaluate the effectiveness of treatment.

Keloid scars are common benign fibroproliferative reticular dermal lesions with unknown etiology and ill-defined management with a high rate of recurrence post-surgery. The progression of keloids is characterized by increased deposition of extracellular matrix proteins, invasion of the surrounding healthy skin, and inflammation.

Fibroblast activation protein alpha (FAP-a) and dipeptidyl peptidase IV(DPPIV) are proteases located at the plasma membrane promoting cell invasiveness and tumor growth and have been previously associated with keloid scars. Thus this prospective study is going to investigate whether 68Ga-FAPI PET/CT may be superior for diagnosis, therapy response assessment, and follow-up of keloid.

This study aims to explore whether FAP plays a role in the mechanisms of scar tissue progression, as well as the diagnostic efficacy of these two imaging agents, and to be able to evaluate relevant treatments for personalized therapy.

Inclusion Criteria:

• suspected or confirmed pulmonary fibrosis patients;
• signed written consent.

Exclusion Criteria:

• pregnancy;
• breastfeeding;
• known allergy against FAPI
• any medical condition that in the opinion of the investigator may significantly interfere with study compliance