PT - JOURNAL ARTICLE AU - Dendl, Katharina AU - Koerber, Stefan A. AU - Finck, Rebecca AU - Tamburini, Katharina AU - Staudinger, Fabian AU - Kratochwil, Clemens AU - Debus, Jürgen AU - Haberkorn, Uwe AU - Giesel, Frederik TI - <strong>FAP-ligands and uterine fibroids: subsidiary findings in cancer imaging </strong> DP - 2022 Aug 01 TA - Journal of Nuclear Medicine PG - 3096--3096 VI - 63 IP - supplement 2 4099 - http://jnm.snmjournals.org/content/63/supplement_2/3096.short 4100 - http://jnm.snmjournals.org/content/63/supplement_2/3096.full SO - J Nucl Med2022 Aug 01; 63 AB - 3096 Introduction: Fibroblast activation protein (FAP) is upregulated by cancer associated fibroblasts and, thereby, mainly elevated in neoplastic tissue. However, FAP is also overexpressed during tissue remodeling, at sites of inflammation, wound healing and non-malignant diseases. Hence, we sought to evaluate the phenomenon of uterine fibroides induced uptake in oncological patients receiving 68Ga-FAPI-PET/CT.Methods: This retrospective preliminary analysis comprises 16 cancer patients with uterine fibroides undergoing 68Ga-FAPI-PET/CT. Quantification of tracer uptake was determined based on standardized uptake values (SUVmean and SUVmax). Furthermore, the uteri of 95 women within a similar age range were measured in order to establish a referential physiological uptake. Results: The evaluation determined a considerably high mean SUVmean of 6.4 and SUVmax of 11.7. The referential physiological uptake (n=95; range 47-77y) presented significantly lower mean uptake in terms of SUVmean (1.9; p&lt;0.0001) and SUVmax (3.1; p&lt;0.0001) compared to tracer accumulation in patients with uterine fibroides. Conclusions: This preliminary investigation of FAPI accumulation in benign lesions clearly reveales uterine fibroides as subsidiary findings. These identified lesions presented significantly higher tracer uptake than the established referential physiologic standard. The knowledge of tracer accumulation in benign conditions is critical to assure accurate interpretation of FAPI-PET/CT scans and therefore, urgently requires further (cross)-validation.