RT Journal Article SR Electronic T1 The Radiotoxicity of 131I Therapy of Thyroid Cancer: Assessment by Micronucleus Assay of B Lymphocytes JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 608 OP 611 VO 45 IS 4 A1 Naoto Watanabe A1 Hirokazu Kanegane A1 Seigo Kinuya A1 Noriyuki Shuke A1 Kunihiko Yokoyama A1 Hiroshi Kato A1 Gakuto Tomizawa A1 Masashi Shimizu A1 Hisashi Funada A1 Hikaru Seto YR 2004 UL http://jnm.snmjournals.org/content/45/4/608.abstract AB We investigated cytologic radiation damage in thyroid cancer after 131I therapy using micronucleus assay (MNA) of B lymphocytes exclusively, as opposed to our previous study in which MNA of all lymphocyte subsets was used. Methods: We studied 22 thyroid cancer patients treated with 3.7 GBq of 131I. Peripheral lymphocytes were harvested, and B lymphocytes were isolated by an immunomagnetic method and assayed for the frequency of micronuclei. Results: The frequency of micronuclei among B cells after 131I therapy was significantly increased relative to that in untreated control subjects, and the 131I-induced increase in micronuclei frequency among B cells was significantly greater than that among all lymphocytes. Conclusion: Compared with the MNA of all lymphocytes, the MNA among specifically B cells may more sensitively detect cytologic radiation damage associated with 131I therapy of thyroid cancer.