en Radiation Biology Radiation Biology گزارش کوتاه Short Report <div style="text-align: justify;"><span style="font-size:10pt"><span style="text-justify:newspaper"><span style="text-kashida-space:50%"><span style="line-height:119%"><span style="font-family:Calibri"><span style="color:black"><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Background</span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-weight:bold"><span style="language:en-US">:</span></span></span></span></span> <span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">The aim of this study was to evaluate the radiation dose effect of a low-dose chest computed tomography (CT) protocol implemented in our hospital during the outbreak of Coronavirus disease 2019 (COVID-19) by estimating lifetime attributable risk (LAR). </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Materials and Methods:&nbsp; </span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">A total of 583 patients were randomly included in this study. The values of volumetric CT dose index (CTDIvol, mGy) and dose length product (DLP, mGy.cm) were extracted from CT console. CT-Expo is a CT dose software that was used to estimate effective dose (E) and organ doses. Lifetime attributed risk (LAR) of cancer incidence were calculated according to the Biological Effects of Ionizing Radiation (BEIR) VII report. </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Results: </span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">Of the 583 patients included in this study, 262 (44.9%) were men and 321 (55.1%) were women. The third quartile of CTDIvol and DLP were 2.5 mGy and 79.4 mGy.cm, respectively. The mean value of E was 1.1 &plusmn; 0.3 mSv, and it was statistically higher in females. Esophagus, lung and thymus received highest doses, and also in females breast received highest dose. The mean LAR of lung cancer was 5.3 per 100,000 patients, while the mean LAR of liver cancer was 0.1 per 100,000 patients. </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Conclusions: </span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">Despite the large number of chest CT scans during the Covid-19 era, the low-dose chest CT protocol implemented in our hospital caused low doses to organs and very low cancer risks.</span></span></span></span></span></span></span></span></span></div> Tomography, X-Ray computed, Covid-19, lifetime risk, radiation exposure. 501 504 http://ijrr.com/browse.php?a_code=A-10-1-1200&slc_lang=en&sid=1 F. Rasoulinejad 7900319475328460027843 7900319475328460027843 No Faculty of Medicine, Gonabad University of Medical Sciences, Gonabad, Iran M. Keshtkar Keshtkar.dmohammad@yahoo.com 7900319475328460027844 7900319475328460027844 Yes Medical Physics and Radiology Department, Faculty of Medicine, Infectious Diseases Research Center, Gonabad University of Medical Sciences, Gonabad, Iran