thyroid cancer risk in patients undergoing 64 slice brain and paranasal sinuses computed tomography

Purpose: computed tomography (ct) is a fundamental part of diagnosis of diseases. during ct examinations organs in and out of scanned volume are exposed to ionization radiation. the aim of this study was estimation thyroid cancer risk in patients who underwent 64 slice brain and paranasal sinuses ct scan.materials and methods: with permission from the authors and editor, data related to thyroid dose of 40 patients in mazyar et al.'s paper was used and by using biological effects of ionizing radiation (beir)vii model thyroid cancer risk was calculated for different ages at exposure in male and female.results: in both brain and paranasal sinuses ct, err values in female patients were twice as many as those in male patients. at age range from 20 to 40 years, err was considerably more than at age range 40-60 years since young patients are more radiosensitive than old patients.conclusion: the calculations of err indicate that pns and brain ct increase the theoretical risk of thyroid cancer incidence. although the err values are low, impacts on the thyroid cancer incidence should not be disregarded.