The radiotoxicity of 131I therapy of thyroid cancer: assessment by micronucleus assay of B lymphocytes.

UNLABELLED: We investigated cytologic radiation damage in thyroid cancer after (131)I 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 (131)I. 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 (131)I therapy was significantly increased relative to that in untreated control subjects, and the (131)I-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 (131)I therapy of thyroid cancer.