Myocardial uptake of bone scintigraphic agents associated with increased pulmonary uptake

Due to delivery problems with the most commonly used bone scintigraphic agent medronate-(99m)Tc-methylene diphosphonate (MDP) (medronate), several regional institutions changed, at various time points, to (99m)Tc-dicarboxypropane diphosphonate (DPD) (Teceos) from 2010. Extraosseous uptake, in particular, myocardial uptake, was observed in a number of patient examined with DPD, with reduced quality of the bone scans. Additionally, an increase in pulmonary uptake was apparent in many of these patients. The aim of this quality control was to assess pulmonary soft tissue uptake in the patients with high myocardial uptake.

A retrospective analysis of the 2435 bone scintigraphies performed during a 3-year period revealed relatively intense myocardial uptake in 10 of the 1195 patients examined with DPD (Teceos). A comparison of pulmonary uptake in a control group of age- and gender-matched subjects and a control group of patients examined with the same preparation of DPD were assessed.

In patients with cardiac uptake of DPD, it could also be shown a relatively intense background uptake in the lungs with significantly higher uptake ratio over intercostals regions versus the abdomen, compared to the control groups. Furthermore, we found, as already well documented, a significantly lower bone to soft tissue uptake in these patients, as quantified by a femur to surrounding soft tissue ratio.

Cardiac uptake of bone scintigraphic agents is associated with high pulmonary uptake. This may be a sign of pulmonary involvement which may give extraosseous bone tracer uptake its own importance and DPD a new role.