Ralph M. Kniseley

DISTRIBUTION OF COLLOIDAL RADIOACTIVE CHROMIC PHOSPHATE AFTER INTRACAVITARY ADMINISTRATION

Colloidal radioactive gold, Au198, has been used for several years in the palliative treatment of patients with recurrent pleural and abdominal effusions caused by malignant neoplasm. Its use has been reasonably well established and evaluated, but the results, although encouraging, leave much to be desired. The extent of the contribution of the gamma emission of the radioactive gold to the therapeutic result is not known, but this component of the radiation produces a total-body effect that is undesirable. An isotope which, like colloidal gold 198, remains largely in the region of the injected cavity, yet has only a beta emission, would have the advantage of producing less total-body irradiation. Since the need for protecting the operator against gamma radiation complicates the use of the gold, a beta emitter would also be easier to administer. P32 with an energetic beta emission of 1.72 mev, in the form of a colloid, chromic phosphate, should be useful for this purpose. The chromic phosphate can be made ...

INTRACAVITARY USE OF COLLOIDAL RADIOACTIVE GOLD

Among the radioisotopes which have therapeutic value is radioactive gold, AU198. It has a half-life of 2.8 days and decays with both beta and gamma emissions. One peculiar advantage of this element is that it can be prepared as a colloid which is chemically stable and relatively inert biologically. Dr. Paul Hahn, of Meharry Medical College, has introduced the use of this isotope for direct injection of tumors and intravenous administration (1, 2, 3). Its value as a means of irradiating body cavities for the control of fluid accumulation is the subject of the present discussion. This use for the isotope was first suggested by J. Muller (4), of Switzerland. During the last two years our group at the Oak Ridge Institute has been carrying on a program of experimental treatment with radioactive colloidal gold. The present discussion is based largely upon material which has already appeared in other publications (5–8). We have injected the isotope into pleural and peritoneal spaces of patients with effusions ca...