ABSTRACT
Cytological radiation damage to lymphocytes can result in augmentation of cells with micronuclei. In this study we investigated Cytological radiation damage to peripheral blood lymphocytes using the micronuclei assay [MNA] method. Considering the value of Iodine-131 in diagnostic and therapeutic nuclear medicine and high absorbed dose of I131 radioiodine in comparison with gamma emitters and the effect of type of radiation, dose and species on radiosensitivity of patients, this study was conducted. To evaluating the Cytological radiotoxicity of therapeutic radiotracers such as radioiodine I131. We studied 22 patients with differential thyroid carcinoma who were referred for treatment with 100 or 150 mci I131. Before and one weak after treatment the peripheral lymphocytes were harvested and isolated by a Cytological method and assayed for frequency of micronuclei as a marker of Cytological radiotoxicity. The means of micronuclei in one hundred binuclear lymphocytes were 6.3 +/- 2.2 before treatment and 9.6 +/- 3.1 after treatment, differences in the number of micronuclei being statistically significant [p value <0.05]. High doses of radioiodine therapy used after surgery for differentiated thyroid carcinoma can increase micronuclei among peripheral lymphocytes as an indirect marker of chromosomal aberrations and cytotoxic radiation damage