Evaluation of The Increasing Use of Ct Scan in Covid-۱۹ Pandemic And Its Effect on The Risk of Radiation-Induced Cancers in Zanjan

Background: With the spread of COVID-۱۹ and its impact on patients' lungs, the number of lung CT scans was increased. Considering the harmful effects of ionizing radiation, this study has investigated the increased number of CT scans in the COVID era and its effect on the probability of radiation-induced cancer in Zanjan.Methods: In this cross-sectional-analytic study, all lung CT scans performed during the fall of ۲۰۱۹ (before the pandemic) and ۲۰۲۰ (pandemic peak in Iran) in the hospitals of Zanjan were included. Images, demographic information of the patients, and the absorbed dose (DLP) were obtained from PACS. All scans were reviewed by a radiologist for COVID signs. The radiation-induced cancer probability was calculated using ICRP ۱۰۳. Independent t-test was used for statistical analysis.Results: ۱۱۳۰۵ (۴۵.۵% female and ۵۴.۵% male) lung CT scans were included in this study. The number of lung scans performed in ۲۰۱۹ was ۲۲۳۵ and ۹۰۹۵in ۲۰۲۰. The mean age of patients in ۲۰۱۹ was significantly lower than in ۲۰۲۰ (۶۰.۲۲±۱۹.۲۶ and ۴۹.۹۸±۱۹.۱۱, respectively (P<۰.۰۵)). Only ۵۵.۶% of ۲۰۲۰ scans showed COVID infection, the rest were normal. The mean DLP of scans performed in ۲۰۱۹ and ۲۰۲۰ were ۱۸۴.۲۳ (SD=۹۳.۲۵) and۱۷۲.۵۴ (SD=۱۰۷.۸۶), respectively (P<۰.۰۵). There was a slight decrease in the probability of one new case of cancer (esophagus, lung, breast, and thyroid cancer) per ۱۰,۰۰۰ people due to lung scans in ۲۰۲۰ compared to ۲۰۱۹, but the number of scans was ۴ times greater than in ۲۰۱۹.Conclusion: although radiotechnologists have reduced the absorbed dose of patients in ۲۰۲۰ and this has reduced the possibility of thoracic cancers, but the number of lung scans has multiplied by ۴. Also, COVID-۱۹ has caused the average age of patients referred for lung scan to decrease by more than ۱۰ years. Half of the lung scans were normal, which indicates the indiscriminate use of CT scans. All these together will increase the radiation-induced cancer incident rate.

کلیدواژه ها:

CT scan ، Absorbed dose ، Cancer ، Coronavirus ، pandemic