To advance the design of self-assembled metallosupramolecular architectures as new generation theranostic agents, the synthesis of 18F-labelled [Pd2L4]4+ metallacages is reported. Different spectroscopic and bio-analytical methods support the formation of the host-guest cage-cisplatin complex. The biodistribution profiles of one of the cages, alone or encapsulating cisplatin have been studied by PET/CT imaging in healthy mice in vivo, in combination to ICP-MS ex vivo.