A comparison between the diagnostic efficacy of 99mTc-MDP, 99mTc-DPD and 99mTc-HDP for the detection of bone metastases.

We have investigated the clinical efficacy for the detection of bone metastases of two recently marketed bone-seeking radiopharmaceuticals, HDP and DPD, compared with traditionally used MDP. Twenty patients received 15 mCi 99mTc-MDP; after assessment ten of these patients later received 15 mCi 99mTc-DPD and ten other patients of this group were injected with 15 mCi 99mTc-HDP. Scintigraphy took place 3 h after tracer injection. Quantitative analysis included the calculation of normal bone to soft tissue ratios, lesion to soft tissue ratios and lesion to normal bone ratios for all three radiopharmaceuticals. Visual inspection of the scintiphotos revealed the same number of bone lesions at the same localisations.