INVIVO ANALYSIS OF BONE CALCIUM BY LOCAL NEUTRON-ACTIVATION OF THE HAND - RESULTS IN NORMAL AND OSTEOPOROTIC SUBJECTS

Abstract

Mineral loss from bone can be measured accurately and reproducibly by neutron activation of the hand bones using a 5-min irradiation (106 n(neutron?)/cm2-s) with two 200-.mu.g sources of Cf-252. The hand dose is 7.5 rad equivalent and the dose to the rest of body is 1.5 mrem. Controls (132) and osteoporotic patients (45) were compared. Between ages 20-60 the control group showed a bone Ca concentration of 0.177 .+-. 0.025 g/cm3, independent of age. Between 60-70 the content remained unchanged in men but declined in women to 0.15 .+-. 0.2 g/cm3. In all age groups, osteoporotic patients in general showed lower Ca content. Comparison of the findings (Ca) with estimates of bone mineral content obtained by photon absorptiometry (BMC) yields 0.07 Ca + 0.262 (r [correlation coefficient] = 0.87). Activation analysis of hand bone appears more precise than BMC for the monitoring of bone-mineral loss in each individual and as a measure of treatment efficacy.