Radiation Dose to the Breasts during Thoracic CT

Introduction: Thoracic CT is a frequent CT examination that contributes to radiation exposure of ionizing radiations to the breasts. The superficial position and expose to low energy scattered photons placed the breasts at risk to receive high radiation exposure during thoracic CT. This is of particular concerns as the breast tissue is highly sensitive to radiation. Therefore, it is necessary to monitor the breast received dose and ensures that the dose is kept as low as reasonably achievable. The aim of this study was to evaluate the radiation dose to the breasts in patients undergoing thoracic CT.Material and Methods: After primary coordination, 40 female patients (18 years or older) who were referred to clinically indicated thoracic CT at our institution were recruited into the study. The LiF: Mg, Cu, P thermoluminescent dosimeters (TLD) were used for radiation dose measurements. Before the study, the TLDs were calibrated. Five TLDs were placed on the surface of each breast and the standard scan was performed. The SPSS software version 20 was used for data analysis.Results: The patients’ age was ranged from 18 to 76 years. The mean of absorbed dose at the surface of the right and left breast was obtained 23±4.1 mGy and 22±3.9 mGy, respectively. There was a direct correlation between patents age and the received dose.Conclusion: The radiation dose delivered to the breast during thoracic CT in our study was exceeded the values reported in the literatures and it may be a reason for concern. Strict adherence to the safety guideline is seems to be necessary.

Keywords:

thoracic , CT , breast , radiation dose , patient