Modification of Strontium 90 Emission for Superficial Therapy

Abstract

The heteroenergetic emission of [beta]- particles from radioactive materials may be modified for the more favorable treatment of superficial disease. In this study the [beta] particles emitted by a Sr 90 source within an angle of 80 degrees were screened and redirected by a magnetic selector. The output consisted of a broad field of electrons moving in the same direction and with a selected range of energies controllable by the magnetic field. The distribution of ionization in depth of tissue produced by the highest energy band, 1[center dot]4 to 2[center dot]1 MeV, was similar to that produced by monoenergetic 1.6 MeV electrons.