The Effect of 99m Tc on Dual-Energy X-Ray Absorptiometry Measurement of Body Composition and Bone Mineral Density

Contemporary methods of body composition measurement

“…The precision of DXA determination of whole‐body FM expressed as CV ranges from 0·8 to 2·7% (SEM 0·39–0·5 kg) and for lean soft tissue 0·4–1·3 % (SEM 0·35–0·54 kg) in sequential measurements (Johnson & Dawson‐Hughes, ; Tothill et al ., ; Kiebzak et al ., ; Cordero‐MacIntyre et al ., ; Genton et al ., ; Hind et al ., ; Fosbol et al ., ). Precision of regional body composition measurements has been reported to be poorer than whole‐body measurements, particularly for fat mass of the trunk (Johnson & Dawson‐Hughes, ; Tothill et al ., ; Kiebzak et al ., ; Cordero‐MacIntyre et al ., ; Hind et al ., ).…”

“…Other sources of potential errors in DXA measurement involve inaccurate positioning of the subject, especially for regional composition analysis (Libber et al ., ), presence of metallic implants (Henderson et al ., ), antecedent administration of radioactive tracer to the patient (Fosbol et al ., ) or the limitation that some subjects are too wide or too tall for the scan field. The latter can be compensated for in tall subjects by scanning the head and trunk + limbs in two separate scans (Evans et al ., ; Santos et al ., ).…”

DXA: Technical aspects and application

“…In literature the most controversial effects have been reported for nuclear medicine isotopes. Two recent studies reported opposite conclusions: (a) caution should be taken when interpreting the results of DXA scans performed in proximity to procedures involving the administration of technetium (significant decrease in fat mass and bone and a corresponding increase in lean mass) and (b) DXA may be performed simultaneously with technetium and iodine therapy, respectively [29,30].…”

Bone Mineral Densitometry Reporting: Pearls and Pitfalls

“…Therefore, it is important that standard operating procedures are in place to identify and delay DXA testing in order to mitigate these effects. Fosbøl et al 21 studied the effects of antecedent administration of 99m Tc-labeled radiotracers on patients undergoing DXA. Using both patient and phantom measurements, they found a significant dose-related decrease in BMD values in patients who had received radiotracer injection; however, other investigators have found no such effect.…”