A METHOD FOR MAINTENANCE OF CURIE QUANTITIES OF Y90-DTPA IN THE HUMAN BODY FOR DEFINED TIME PERIODS: TECHNIQUE AND DOSIMETRY.

A procedure is described by which a radioactive isotope may be maintained at a constant level within the body for a specified period followed by rapid removal of the isotope from the body under controlled conditions. The particular isotope used in these experiments was yttrium-90 chelated with DTPA. The procedure lends itself to use with any radioactive isotope which is either quantitatively excreted by the kidneys or which can be attached firmly to a suitable chelating agent that is rapidly cleared from the body by the kidneys. The methods and equipment necessary for continuous processing and intravenous recycling of urine containing high concentiations of a radioisotope are described. A method for estimating dosimetry is presented for injected Y/sup 90/-DTPA which is in equilibrium with plasma. However, this method has general applicabilities for any BETA or alpha emitting isotope used in the manner described. (auth)