ALB and neoplasm: In this study, we site-selectively radiolabeled HSAwith zirconium-89 (89Zr), using the octadentate chelatorDFO*, to provide an imaging probe with enhanced stability and sufficienthalf-life to elucidate the long-term (tumoral) albumin homeostasis.[89Zr]­Zr-DFO*malHSA demonstrated excellent metabolic stabilityand high tumor uptake in a longitudinal PET study (72 h p.i.)usinga subcutaneous colorectal cancer allograft model (CT26).