Effect of Cobalt-60 Irradiation upon Cell-Mediated Immunity

Abstract

In a study of 45 humans, the effects of cancericidal cobalt-60 radiation upon cell-mediated immunity was estimated in vivo by determination of delayed hypersensitivity response (DHR) to a nonspecific challenge system—dinitrochlorbenzene. Therapeutic doses of cobalt 60 did not adversely affect the immune responses in 85% of the patients studied, as measured by this method. The method is considered superior to the previously described in vitro procedures that lead to ambiguous conclusions. Further deterioration of DHR in the remaining 15% of patients is attributed to natural biological tumor burden rather than to radiation effect.