Study of cytogenetic toxicity of low-dose radioiodine therapy in hyperthyroid patients using a micronuclei assay.

OBJECTIVE

Radioiodine, in low doses, has been used as a treatment modality for hyperthyroidism worldwide for a long time. However, there is little information available on the severity of cytotoxicity of radioiodine at these low doses. The present investigation aimed to study the cytogenetic toxicity of low-dose radioiodine in hyperthyroid patients using a cytokinesis-blocked micronuclei (MN) assay.

MATERIALS AND METHODOLOGY

All of the patients received radioiodine in the form of sodium iodine (oral form). Blood samples of these patients were collected before therapy and 3 months after therapy, and lymphocytes were analysed for MN assay.

RESULTS

Peripheral blood lymphocytes were analysed in 74 hyperthyroid patients (52 men, 22 women). The results indicated a positive relationship between age and the frequency of MN. However, there was no statistically significant difference in MN frequency at 3 months after therapy in comparison with that before therapy.

CONCLUSION

This study showed that the cytogenetic damage produced by low-dose radioiodine was transient and reversible. Thus, patients can be motivated to undergo this safe and easy procedure as a modality of treatment for hyperthyroidism.