Ikuro Anzai

Estimation of whole body absorbed dose of the patient administered 57Co-bleomycin for tumor diagnosis.

The whole body absorbed dose of the patient administered 57Co-Bleomycin for tumor diagnosis was estimated in accordance with the MIRD Committee method. The whole body retention function was well described by the two component exponential model. The effective half-lives were several hours in the initial rapidly decreasing phase and 2-3 months in the successive slow phase. The accumulated whole body absorbed dose following intravenous administration of 1mCi of 57Co-Bleomycin was calculated to be approximately 3 rads, more than 90% of which was delivered in the first one year following injection. It was also revealed that no less than 99% of the dose was brought by the slow phase component, which indicated the importance of obtaining slow phase excretion date for dose estimation concerning the newly applied radiosubstances, irrespective of necessity or unneeessity for the diagnosis itself. Relatively high level of deposition was observed in the liver of a male patient of 82 years old who died of lung cancer 15 days after intravenous injection of 57Co-Bleomycin.