Radiation dose and cancer risks from radiation exposure during abdominopelvic computed tomography (CT) scans: comparison of diagnostic and radiotherapy treatment planning CT scans

In the present study, radiation doses and cancer risks resulting from abdominopelvic radiotherapy planning computed tomography (RP-CT) and abdominopelvic diagnostic CT (DG-CT) examinations are compared. Two groups of patients who underwent abdominopelvic CT scans with RP-CT (n?=?50) and DG-CT (n?=?50) voluntarily participated in this study. The two groups of patients had approximately similar demographic features including mass, height, body mass index, sex, and age. Radiation dose parameters included CTDI_vol, dose–length product, scan length, effective tube current, and pitch factor, all taken from the CT scanner console. The ImPACT software was used to calculate the patient-specific radiation doses. The risks of cancer incidence and mortality were estimated based on the BEIR VII report of the US National Research Council. In the RP-CT group, the mean?±?standard deviation of cancer incidence risk for all cancers, leukemia, and all solid cancers was 621.58?±?214.76, 101.59?±?27.15, and 516.60?±?189.01 cancers per 100,000 individuals, respectively, for male patients. For female patients, the corresponding risks were 742.71?±?292.35, 74.26?±?20.26, and 667.03?±?275.67 cancers per 100,000 individuals, respectively. In contrast, for DG-CT cancer incidence risks were 470.22?±?170.07, 78.23?±?18.22, and 390.25?±?152.82 cancers per 100,000 individuals for male patients, while they were 638.65?±?232.93, 62.14?±?13.74, and 575.73?±?221.21 cancers per 100,000 individuals for female patients. Cancer incidence and mortality risks were greater for RP-CT than for DG-CT scans. It is concluded that the various protocols of abdominopelvic CT scans, especially the RP-CT scans, should be optimized with respect to the radiation doses associated with these scans.