Age- and sex-related bone uptake of Tc-99m-HDP measured by whole-body bonescanning

Aim of this study was to validate a recently introduced new and easy-to-per form method for quantifying bone uptake of Tc-99m-labelled diphosphonate in a routine clinical setting and to establish a normal data bose for bone up take depending on age and gender. Methods: In 49 women (14-79 years) and 47 men (6-89 years) with normal bone scans as well as in 49 women (33-81 year s) and 37 men (27-88 years) with metastatic bone disease whole-body hone sc ans were acquired at 3 min and 3-4 hours p.i. to calculate bone uptake afte r correction for both urinary excretion and soft tissue retention. Results: Bone uptake values of various age-related subgroups showed no significant differences between men and women (p > 0.05). Furthermore, no differences c ould be proven between age-matched subgroups of normals and patients with l ess than 10 metastatic bone lesions, while patients with wide-spread bone m etastases revealed significantly increased uptake values. in both men and w omen highest bone uptake was obtained (p <0.05) in subjects younger than 20 years with active epiphyseal growth plates. In men, bone uptake slowly dec reased with age up to 60 years and then showed a tendency towards increasin g uptake values. In women, the mean uptake reached a minimum in the decode 20-29 years and then slowly increased with a positive linear correlation of age and uptake in subjects older than 55 years (r = 0.57). Conclusion: Sin ce the results proposed in this study ore in good agreement with date from literature, the new method used for quantification could be validated in a large number of patients, Furthermore, age- and sex-related normal bone upt ake values of Tc-99m-HDP covering a wide range of age could be presented fo r this method as a basis for further studies on bone uptake.