Sarah Verhoeff

35 Lesion detection by [89Zr]Zr-DFO-girentuximab and [18F]FDG PET/CT in mccRCC patients Upon completion of the follow-up data of all patients included in the IMPACT-RCC study, we will analyze whether [89Zr]Zr-DFO-girentuximab and [18F]FDG-PET/CT contributes to a better prediction of the course of disease during watchful waiting in good and intermediate prognosis mccRCC patients. Conclusions The addition of [89Zr]Zr-DFO-girentuximab-PET/CT and [18F]FDG-PET/CT to CT increases lesion detection compared to CT alone in newly diagnosed good and intermediate prognosis mccRCC patients eligible for watchful waiting. The quantitative analyses of [89Zr]Zr-DFO-girentuximab and [18F]FDG-uptake can be relevant in clinical practice, as site-specific heterogeneity may require a different treatment approach. 2