RT Journal Article SR Electronic T1 131I in Blood Samples: A Danger for Professionals? A Problem for Immunoassays? JF Journal of Nuclear Medicine Technology JO J. Nucl. Med. Technol. FD Society of Nuclear Medicine SP 172 OP 174 VO 33 IS 3 A1 Julie Vialard-Miguel A1 Agnès Georges A1 Joaquim Mazère A1 Dominique Ducassou A1 Jean-Benoît Corcuff YR 2005 UL http://tech.snmjournals.org/content/33/3/172.abstract AB Objective: Our objective was to investigate the safety of radioactive blood samples from patients receiving 131I and whether the radioactivity affects the validity of assays. Methods: First, the activity of samples from patients given 131I was measured by 3 methods and compared with the upper threshold. Then, pilot sera were spiked with 131I, and possible interference was investigated using 2 immunoradiometric assays. Results: The activity of 13 of the 15 samples was below the European limit; the other 2 samples were from patients with reduced renal clearance rates. No differences in thyroglobulin level or thyroid-stimulating hormone level were found between sera that were spiked with 131I and sera that were not. Conclusion: These blood samples are safe because they contain negligible activity, and the use of radioimmunoassays or immunoradiometric assays on them produces reliable results.