Effective half-lives for patients administered radiolabeled antibodies and calculated dose to the public in close proximity to patients

Effective half-lives (Te) for radiolabeled antibodies can be much longer than that of traditional radiopharmaceuticals, potentially resulting in larger doses to members of the public. Clearance-rate data from patients treated with radiolabeled antibodies (RABs) were obtained from ten institutions. Calculations were made to determine if a single- or bi-exponential clearance-rate model was statistically justified; the results indicated that the former model was justified for more than 95% of the data. Values of Te for the different RABs are summarized. To plan actions to limit doses to less than 5 mSv annually for individuals continuously close to the patient (at 1 m), dose rates from patients at the time of release also are given as a function of Te