International Journal of Radiation Research

en Establishment of regional diagnostic reference level for CT planning of breast cancer and comparing them with international values Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;">Background: All over the world, Computed Tomography (CT) scan is used as an essential method in radiation therapy treatment planning. Ionizing radiation for the medical exposures should follow principle "As Low as Reasonably Achievable" (ALARA) to reduce the dose. The objective of this study is to establish a Diagnostic Reference Level (DRL) for breast Computed Tomography planning (CTp) and compare it with other DRLs because there are no dose guidelines for breast cancer CTp in Iran. The established DRL can be used for dose optimization in CT planning. Materials and Methods: We surveyed six RT centers in Tehran and collected data from patients with breast cancer, who were of average size, regarding the volume Computed Tomography Dose Index (CTDIvol), the dose length product (DLP), the dose parameters, the scan length, the thickness of the slices, and the use of automated exposure control (AEC). DRLs were calculated for each dose descriptor using the rounded 75th percentile of the distribution of means. Results: Data were collected on a total of 90 breast cancer CT localization scans from six CT centers. Significant variation was observed in mean DLP and mean CTDIvol among centers (p value < 0.0001). Moreover, mean mAs and scan length significantly differed across centers (p < 0.0001). Calculated DRLs for breast localization are 296.29 mGy cm and 6.64 mGy for DLP and CTDIvol, respectively which were lower compared with other studies conducted in this field. Conclusion: There were differences in doses used for breast CT planning among centers. DRLs were proposed for dose optimization and patient radiation protection in CT planning.</div> Radiotherapy, CT planning, breast cancer, Dose Reference Level, dose optimization. 999 1007 http://ijrr.com/browse.php?a_code=A-10-1-1269&slc_lang=en&sid=1 E. Hasanpour 7900319475328460028704 7900319475328460028704 No Radiation Science Department, Faculty of Allied Medicine, and Radiation Biology Research Center, Iran University of Medical Sciences, Tehran, Iran A. Maziar asgharmaziar@hotmail.com 7900319475328460028705 7900319475328460028705 Yes Radiation Science Department, Faculty of Allied Medicine, and Radiation Biology Research Center, Iran University of Medical Sciences, Tehran, Iran R. Paydar paydar.r@iums.ac.ir 7900319475328460028706 7900319475328460028706 No Radiation Science Department, Faculty of Allied Medicine, and Radiation Biology Research Center, Iran University of Medical Sciences, Tehran, Iran A. Nikoofar 7900319475328460028707 7900319475328460028707 No Department of Radiation Oncology, School of Medicine, Iran University of Medical Science, Tehran, Iran