The Turnover of Strontium-85 in Man as Determined by Whole-Body Counting

Publisher Website
Google Scholar
Abstract
The retention of intravenous tracer doses of Sr85 was measured in 10 patients directly by whole-body counting, and indirectly by urinary and fecal S85r excretion. Sr85 retention, determined by the 2 methods, differed during the first few days after administration of the isotope, inasmuch as the changing pattern of tissue distribution of the Sr85 altered the geometry and thus the counting efficiency of the Nal crystal detector of the whole-body counter. Retention in long-term studies can be expressed either as a series of exponentials or as a single-term power function. The mean biological half-life of Sr for 6 patients, was 843 days, during the period 100 to 320 days. The mean value for radiostrontium retention, R, as a function of time for these 6 patients in the period 30 to 397 days after intravenous injection of the Sr85 was given by the power function R = 52.2t-0.175. As the "final" ex-ponential term from which the half-life value is derived has been shown to depend on the period of time over which it is determined, it is preferable to use the power model to estimate retention over long periods. More long-term data on isotope retention are necessary to chose between the 2 mathematical models for the biological turnover of Sr over a human life span.

This publication has 6 references indexed in Scilit: