Cytogenetic Studies of Chromosome Abnormalities in Thyroid Cancer Patients Before and After Iodine-131 Treatment

Objective: Thyroid cancer is among the most common endocrine malignancies. Initial management consists surgery and ablation. I-131,which is used to damage surgically unremoved thyroid tissue or treat metastases, is a source for ionizing radiation (IR), also generates potential mutagenic and carcinogenic effects. The purpose of research is to investigate the damage on chromosomes at the I-131 treatment of thyroid cancer patients exposed to the same dose of genotoxic agent. Methods: Peripheral blood of 20 patients and 20 healthy control individuals were used in study. Materials were collected from patients before the I-131 treatment and three times on the 15th day, the first and second month after the I-131 treatment. All chromosome abnormalities, spontaneous chromosomal breakages, and sister chromatid exchange (SCE) were analyzed by cytogenetic methods in the samples. Results: The results obtained from peripheral blood of patiens who received ablation therapy revealed no significant increase for chromosome breakages, chromosome abnormalities, and SCE. Karyotyped metaphase spreads showed none of the structural and numerical chromosome abnormalities. The results of chromosome breakages and SCE have been statistically assessed by Aspin Welch test and did not differ from the control group. The t values of this variability were found to be -1.001,-1.654, respectively, and p>0.05. Conclusion: Our results demonstrate that applied therapeutic clinical dose does not show cytogenetic abnormalities risks of the early period in patients. I-131 treatment is a good option for the treatment of thyroid cancer,but also we recommend that physicians should perform long term follow-up examinations for IR exposed patients and prevent possible complications.