The therapeutic application of radioactive phosphorus with special reference to the treatment of primary polycythemia and chronic myeloid leukemia.

The use of radioactive phosphorus in the treatment of disease stems from the initial studies made by Lawrence and his colleagues in 1936 (1). Since then there have been a number of reports which establish the efficacy of this form of therapy in chronic leukemia and polycythemia (2-11). These clinical reports have been issued from a number of separate institutions, indicating that independent experiences are now fairly widespread. The report by Reinhard et al. (12) is an exhaustive review of the clinical course of patients treated in this fashion. Similar studies by Doan et al. (13) and Lawrence et al. (14) add extensively to the data now available in the literature. It is our intention here to add to the clinical observations presented in the previous reports, but we wish particularly to emphasize the pertinent information available from the literature and from our own work which is the basis and rationale for such treatment. The concept of treating disease with internally distributed radioactive materials is not completely new and attempts in this direction have previously been made by introducing into the blood stream some of the naturally occurring elements, such as radium. However, the invention of the cyclotron and more recently the development of high energy nuclear reactors of the Atomic Energy Commission have given considerable impetus to this concept of therapy. This is particularly true because of the wide variety of radioactive elements which can be produced by these devices, some of which have suitable characteristics (desirable half-life, proper radiation characteristics, and satisfactory chemical properties). The rationale of treating patients with radioactive material arises from the desire to irradiate selectively certain specific tissues and to prolong