The mechanisms by which ionizing radiation ultimately produces a clinical result are very complicated, but a study of the process of polymerization offers a suitable approach. Polymerization can be initiated by very low doses of ionizing radiation. The random events occurring within chemicals, within cells, or within tissues after irradiation are the results of effects produced by the energy exchange at the randomly spaced sensitive areas, and the results can be both degradation and synthesis of polymeric matrices. This concept is proposed as an integrating complement to the chemical and target theories of radiation effects. It should also afford a logical basis for the methodical investigation of the place of chemicals in combination with irradiation in the treatment of tumors.