Compositions of high specific activity 117mSn with specific activity of greater than 100 Ci/g Sn and methods of producing the same. The method includes exposing 116Cd to an α-particle beam of sufficient incident kinetic energy and duration to convert a portion of the 116Cd to 117mSn to form an irradiated material. The irradiated material is dissolved to form an intermediate solution containing 117mSn and 116Cd. The 117mSn is separated from the 116Cd to yield high specific activity 117mSn.
