68Ga-NOTA-AE105 is a radioligand targeting urokinase plasminogen activator receptor (uPAR), which is a promising imaging biomarker of tumor aggressiveness. 68Ga-NOTA-AE105 PET/CT will be applied in patients with mCRPC during treatment with Radium-223. PET/CT will be performed before initiation of Radium therapy and after two treatment cycles. The initial semiquantitative uptake (standard uptake values, SUVs) of 68Ga-NOTA-AE105 in metastases as well as the change in these parameters after therapy will be correlated with overall survival and progression free survival.
