This invention relates new radiopharmaceutical conjugates for use in improved methods of diagnosis and treatment of cancer. The radiopharmaceutical conjugate comprises, in sequence: a metabolite that targets tumour cells, bound to a chelating agent capable of containing a radionuclide, bound to a linker capable of binding with an EPR agent in vitro or in vivo or a chelating agent capable of containing a radionuclide, bound to a metabolite that targets tumour cells, bound to a linker capable of binding with an EPR agent in vitro or in vivo. The radiopharmaceutical conjugates of the present invention provide active and passive targeted radio nuclide delivery systems that can help to improve the biodistribution and pharmacological toxicity of the radiopharmaceuticals used for the diagnosis and therapy of cancer.
