Diffusing Alpha-emitters Radiation Therapy or DaRT is an alpha-particle-based radiation therapy for the treatment of solid tumors. This therapy was developed at Tel Aviv University in Israel, by Professors Itzhak Kelson and Yona Keisari. The treatment is delivered by the intratumoral insertion of metal tubes called “seeds”, which have Radium-224 atoms fixed to their surface. When the radium decays, its short-lived daughter Radon-220 is released from the seed through recoil energy. The daughters of Radon-220, in particular Pb-212, disperse in the tumor, and emit high-energy alpha particles, which destroy the tumor. Because the alpha-emitting atoms diffuse only a few millimeters in tissue, the DaRT eradicates the tumor cells and spares the surrounding healthy tissue.