Dose Assessment and Evaluation of Cancer Risk Due to Prevalent CT Scan Procedures

Purpose: The use of Computed Tomography (CT) scans in diagnosis is increasing significantly. This research aims to evaluate the normal brain and chest (CT scans at six medical imaging departments in Tehran, the radiation dose, and the risk of cancer outbreak related to these normal CT scans. Materials and Methods: The information and scan protocols of 1080 patients were collected. Patients were categorized into six groups. NCICT dosimetry software was used to calculate organ dose and cancer incidence evaluated by BEIR VII risk models. Results: Among the 1080 patients, 642 (59%) were males, and the average age of the patients was 45.05 ± 22.60 years. Brain CT scans in 65% of cases and chest CT scans in 52% were reported normal. The third quartile of CTDIvol, DLP, and ED values in the brain and chest scans were calculated and introduced as local DRL values. These values were determined as 22.13, 428.58, and 0.65 for CTDIvol, DLP, and ED values in the brain scan and 5, 187.35, and 3.71 in the chest scan. The highest risk of cancer incidence in the brain scan was related to leukemia, with a value of 0.73 per 100000 exposures, followed by thyroid, with a value of 0.62 in women aged 20-25 years. In the chest scan, the highest risk of cancer incidence was related to breast cancer, with a value of 22.4 per 100000, followed by lung cancer, with a value of 19.02 in the same age group. Conclusion: As age decreases, the risk of cancer increases; therefore, by optimizing the radiation dose and avoiding CT scans without indications, the risk of cancer can be significantly reduced.