Measurement of the secretion of technetium-99m hexamethylpropylene amine oxime into breast milk

There are no published data for the activity of technetium-99m hexamethylpropylene amine oxime (^99mTc-HMPAO) found 1in breast milk. The amount of radioactivity in breast milk following the administration of 500 MBq^99mTc-HMPAO for a brain perfusion study has been measured. The effective dose to the infant was calculated to be 0.26 mSv, so necessitating no interruption of breast feeding. Unbound^99mTc is readily secreted into breast milk and the effective dose will remain less than 1 mSv if the^99mTc-HMPAO labelling effici ency is 99% for the worse reported case, and could remain <1 mSv for the mean reported case for^99mTc-HMPAO labelling efficiencies down to 94%.