Table 1.

Clinical studies about the role of radiolabelled FAPI PET/CT in patients with infectious, inflammatory, or rheumatological diseases published until January 2023 (case reports including less than 5 patients or studies related to other conditions such as renal or myocardial fibrosis are not reported)

Authors	Publication year	Country	Topic on infectious or inflammatory diseases	No. of patients	Main findings
Wang et al. [6]	2023	China	Periprosthetic hip joint infection	103	[⁶⁸ Ga]Ga-FAPI PET/CT seems promising in the diagnosis of periprosthetic joint infection using the diagnostic criteria of the uptake pattern of the radiopharmaceutical
Chen et al. [7]	2023	China	Crohn’s disease	16	[⁶⁸ Ga]Ga-FAPI PET/CT seems a promising method for assessing disease activity in Crohn’s disease. FAPI PET/CT correlated well with endoscopic, computed tomography enterography, and disease biomarkers. It was highly sensitive in the detection of different classes of lesions in all intestinal segments
Treutlein et al. [8]	2023	Germany	Systemic sclerosis	14	[⁶⁸ Ga]Ga-FAPI PET/CT may be a diagnostic option to monitor cardiac fibroblast activity being able to visualize myocardial fibrosis related to systemic sclerosis
Yang et al. [9]	2023	China	Interstitial lung diseases	83	[⁶⁸ Ga]Ga-FAPI PET/CT can assess the profibrotic activity of interstitial lung diseases. Radiolabelled FAPI uptake was significantly related to lung function decline in patients with interstitial lung diseases
Röhrich et al. [10]	2022	Germany	Interstitial lung diseases	15	[⁶⁸ Ga]Ga-FAPI PET/CT is a promising method for detecting fibrotic interstitial lung diseases and associated lung cancer
Wang et al. [11]	2022	China	Light-chain amyloidosis	30	[⁶⁸ Ga]Ga-FAPI PET/CT is feasible in detecting myocardial fibroblast activation in patients with light-chain cardiac amyloidosis in correlation with myocardial remodeling. Radiolabelled FAPI uptake was significantly correlated with cardiac magnetic resonance, echocardiography, and clinical biomarkers
Sviridenko et al. [12]	2022	Austria	COVID-19	6	[⁶⁸ Ga]Ga-FAPI PET/CT may detect pulmonary fibrosis in patients with long-term CT abnormalities after severe COVID-19
Luo et al. [13]	2021	China	IgG-4 related disease	26	[⁶⁸ Ga]Ga-FAPI PET/CT might be promising for the assessment of IgG4-related disease showing higher detection rate compared to [¹⁸F]FDG PET/CT
Schmidkonz et al. [14]	2020	Germany	IgG-4 related disease	27	The combination of [¹⁸F]FDG and [⁶⁸ Ga]Ga-FAPI PET/CT may enable the discrimination between inflammatory and fibrotic activity in IgG4-related disease