METHODOLOGICAL ISSUES OF "JUSTIFICATION" OF CHEST CT IN THE FEMALE POPULATION OF GEORGIA

Abstract

To further refine the criteria for justifying chest computed tomography (CT) scanning in Georgia, taking into account its specific characteristics, this study analyzes the diagnostic value and clinical feasibility of chest CT scanning upon hospital admission of COVID-19 patients. Data on COVID-19 incidence, hospitalization, and mortality in Georgia for 2020–2021 were obtained from the First University Clinic of Tbilisi State Medical University (Georgia) and the National Center for Disease Control and Public Health (NCDC). Prognostic values for the incidence of radiogenic breast cancer among women with COVID-19 hospitalized in 2021 and undergoing chest CT scanning were obtained from our previous work.      
    In the risk-benefit analysis, clinical benefit was defined as the difference between the risk of severe complications or mortality without CT scanning and the residual risk of the same outcomes with CT scanning. This was determined using binary logistic regression methods, receiver operating characteristic (ROC) curve analysis, and Monte Carlo simulations within a Bayesian approach. 
    It was found that, although the results of CT scanning have virtually no effect on the prognosis of complications of the disease, in the group of seriously ill patients they significantly improve the prognosis of a fatal outcome of the disease (sensitivity (with specificity = 0.05) is 0.89 taking into account the results of CT and 0.78 without taking into account the results of CT).
    Based on these data, the age structure of excess mortality in COVID-19 patients in the Georgian population associated with the lack of use of computed tomography was estimated.
    A comparative analysis was conducted between this excess mortality and the prognostic incidence of radiogenic breast cancer in female COVID-19 patients who underwent chest CT. The results indicated that for patients under 40 years of age, excess mortality and breast cancer incidence are approximately equivalent. However, in the 40–59 age cohort, excess mortality exceeds the radiation-induced breast cancer incidence by 80 times, and for patients over 60 years of age, by 1800 times.  From these positions, CT examination for COVID-19 patients under 40 years of age at the time of hospitalization cannot be considered “justified”, in the age range of 40-60 years - desirable, and in patients over 60 years - necessary. The results we obtained practically do not differ from the recommendations of international professional organizations, however, they clearly demonstrate the relevance of quantitative analysis of the "benefit/ risk" in computed tomography from the point of view of radiation protection of the population and indicate promising directions for its methodological provision.