Pharmacokinetics and normal scintigraphic appearance of 99mTc aprotinin

To confirm the pharmacokinetics and biodistribution of 99mTc aprotinin in normal volunteers and to determine the optimum time for scanning post-injection, prior to further investigations of 99mTc aprotinin as an imaging agent for amyloidosis.

Five patients (three men and two women, average age 49 years, age range 38-66 years) without a history of amyloidosis or any of the associated diseases, were included in this prospective study. Blood and urine were collected and images were performed of the whole body and wrists.

Normal biodistribution of 99mTc aprotinin includes early cardiac and lung activity in the blood pool phase with subsequent hepatic activity and renal excretion with variable splenic activity. There is variable bowel uptake on later images. The best quality images were obtained 90 min post-intravenous administration, and this is likely to be the optimum time for clinical imaging.