Unintentional human skeletal imaging with 99mTc-methylene diphosphonate 45 months beyond expiration.

Eight patients were inadvertently administered, and imaged with, 99mTc-labeled MDP which was 45 months expired. Two cases are presented. All patients were subsequently imaged with normal MDP. The images obtained with expired MDP were clinically acceptable. No differences in scan abnormalities were observed compared with normal MDP for any of the patients. None of the patients suffered any side effects attributable to the expired MDP.