Aqueous formulations and kits of radiopharmaceutical compounds of general Formula (II) protected from radiolysis with stabilisers, such as L-methionine and gentisic acid, are disclosed, wherein the compounds are based on sarcophagine ligands coordinated to a radioisotope, such as 64-copper, and linked to a tetrazine group for reaction with tumour targeting antibodies having functional reactive groups such as trans-cyclooctene, processes of preparing said radioligand formulations, and uses thereof for radioimaging, diagnosing and treating cancer.
