PT - JOURNAL ARTICLE AU - Weeks, Joanna K. AU - Pantel, Austin R. AU - Gitto, Sarah B. AU - Liu, Fang AU - Schubert, Erin K. AU - Pryma, Daniel A. AU - Farwell, Michael D. AU - Mankoff, David A. AU - Mach, Robert H. AU - Simpkins, Fiona AU - Lin, Lilie L. TI - [<sup>18</sup>F]Fluorthanatrace PET in Ovarian Cancer: Comparison with [<sup>18</sup>F]FDG PET, Lesion Location, Tumor Grade, and Breast Cancer Gene Mutation Status AID - 10.2967/jnumed.124.267627 DP - 2024 Dec 05 TA - Journal of Nuclear Medicine PG - jnumed.124.267627 4099 - http://jnm.snmjournals.org/content/early/2024/12/05/jnumed.124.267627.short 4100 - http://jnm.snmjournals.org/content/early/2024/12/05/jnumed.124.267627.full AB - Poly(adenosine diphosphate–ribose) polymerase-1 (PARP1) inhibitors have improved ovarian cancer treatment outcomes. However, clinical response remains heterogeneous. Existing biomarkers, mainly breast cancer susceptibility genes 1 and 2 (BRCA1/2), are suboptimal. New tools are needed to guide patient selection. In this study, [18F]fluorthanatrace ([18F]FTT), a PET radiotracer for imaging PARP1, was compared with [18F]FDG and tumor features commonly assessed in ovarian cancer. Methods: Subjects with epithelial ovarian cancer underwent both [18F]FTT and [18F]FDG PET before new oncologic treatment. The SUVmax of [18F]FTT and [18F]FDG was compared between lesions. [18F]FTT SUVmax was compared with tumor location, tumor grade, and germline or somatic BRCA1/2 status. Linear mixed models were fitted to identify subject-level differences. Results: Fifty-five lesions were identified in 14 subjects. No correlation was found between [18F]FTT SUVmax and [18F]FDG SUVmax per lesion, supporting distinct molecular targets. [18F]FTT uptake varied widely across lesions, with no significant differences between mean SUVmax and tumor location, grade, or BRCA1/2 status. Conclusion: Our findings suggest that [18F]FTT PET may provide unique information on ovarian cancer distinct from [18F]FDG PET and commonly assessed tumor features. Our results imply a wide range of PARP1 expression in the studied ovarian tumors not explained by [18F]FDG PET, location, grade, or mutational status.