Abstract: A device and method for radioembolization in the treatment of cancer cells in the body. In preferred embodiments, the device comprises at least two isotopes; wherein a first isotope is focused on therapeutic purposes and a second isotope is focused on dosimetric imaging purposes. In further embodiments, the first isotope is a radiation emitter for therapy where the radiation emitted is primarily alpha particles, and the second isotope is a positron emitter for PET imaging. In preferred embodiments, the isotopes are bound to a single resin microsphere, and an after a radiation dose using the present invention, both treatment and treatment efficacy can be provided to a cancer patient.