Safety of [⁶⁸Ga]Ga-FAPI-46 PET/CT including hemodynamic measurements and patient-reported outcomes in cancer patients

Fibroblast activation protein inhibitor (FAPI) has demonstrated promising oncological diagnostic performance. Although no adverse events (AEs) have been previously reported, a formal safety evaluation of FAPI PET/CT is lacking. This study aimed to assess the safety and tolerability of [⁶⁸Ga]Ga-FAPI-46 PET/CT, with a focus on hemodynamic parameters, AEs, and patient-reported discomfort.

Participants were included from two ongoing prospective diagnostic trials: (1) FAPI PET/CT in ovarian cancer (EU CTIS no. 2023-505938-98-00) and (2) FAPI PET/CT in gastric and gastroesophageal junction cancer (EU CTIS no. 2023-505916-40-01). A dose of 150-250 MBq [⁶⁸Ga]Ga-FAPI-46 was administered, and low-dose, non-contrast CT was performed. Hemodynamic parameters, including systolic and diastolic blood pressure (BP) and heart rate (HR), were measured at baseline, 1-min post-injection (p.i.), 10 min p.i., and post-scan. Additionally, potential AEs and discomfort were assessed at these timepoints and 1 day p.i., and participants were instructed to report events. AEs were graded according to the Common Terminology Criteria for Adverse Events version 5.0.

Thirty participants were included. No patient reported AEs or discomfort attributable to [⁶⁸Ga]Ga-FAPI-46, and no significant changes in mean systolic or diastolic BP were observed; however, three patients experienced increases in systolic BP classified as AEs. A clinically non-relevant but statistically significant (p < 0.01) decrease in HR (from 77 bpm at baseline to 73 bpm at post-scan) was observed.

[⁶⁸Ga]Ga-FAPI-46 PET/CT is well tolerated with no immediate patient-reported discomfort or clinically relevant hemodynamic AEs. The observed decrease in HR from baseline to post-scan likely reflects prescan nervousness.