134 M . Keshtkar : Radioprotection 2024 , 59 ( 2 ), 131 – 137
The risk of lung cancer incidence was highest ( 16.41 ± 4.92 ) in the females RC-CT of G1 age group and lowest ( 8.83 ± 2.36 ) in the females CD-CT of G3 age group . The lowest cancer risk was for thyroid in all three age groups for males and females .
It should be noted that for all three age groups and for males and females , CD-CT groups had statistically lower risk of cancer incidence ( P < 0.05 ).
4 Discussion
Figure 1 . Organ dose of different organs for three age groups .
For the breast in females , the highest dose ( 3.17 ± 0.99 mGy ) was in the RC-CT protocol of the G3 age group , and the lowest dose ( 1.96 ± 0.52 mGy ) was in the CD-CT protocol of the G1 age group . It should be noted that for all three age groups and for males and females , CD-CT groups received statistically lower organ dose ( P < 0.05 ).
Figure 2 shows cancer incidence risk of some organs for G1 , G2 , and G3 . Among the three age groups , the risk of cancer incidence of thyroid , lung , and breast was higher for the G1 age group . The risk of breast cancer incidence was highest ( 19.66 ± 6.14 ) in the females RC-CT of G1 age group and lowest ( 10.66 ± 2.71 ) in the females CD-CT of G3 age group .
Several studies emphasize the importance of minimizing radiation dose in children undergoing CT scans , particularly by employing pediatric-specific imaging protocols and dose reduction techniques ( Miglioretti et al ., 2013 ). Adhering to these guidelines helps to strike a balance between diagnostic accuracy and reducing radiation-related risks in the pediatric population . In this study , we compared the organ dose and cancer risk associated with RC-CT and CD-CT protocols that were implemented in our institution .
Based on Table 2 , the p-values related to effective diameter for the comparison of the two protocols for all age groups was above 0.05 , indicating a good match between the two protocols . In other study ( Bagherzadeh et al ., 2021 ), body mass index ( BMI ) was used to match two groups . However , in this study , we did not have access to BMI data , so we could not use it for matching . Instead , the matching between the two groups ( CD-CT protocol and RC-CT protocol for males and females separately ) was conducted based on an equal number of patients and effective diameter . As expected , the maximum effective diameter was for the oldest group , which is in line with the study by Karim et al . ( 2021 ) study . This is because effective diameter is a measure of the size of the body part being imaged , and older individuals tend to have larger body parts due to factors such as growth , and weight gain . Other factors such as gender and anatomical region can also affect effective diameter , as can be seen from Table 1 , where it is shown that the effective diameter of males is slightly higher than that of females , which is in line with the study by Franck et al . ( 2016 ) and Karim et al . ( 2021 ).
It can be observed that the tube current utilized for CD-CT was lower than that used for RC-CT . The use of a lower tube current can help to reduce the radiation dose to the patient , while the CareDose 4D option can further optimize the radiation dose based on the patient ’ s size and shape . These techniques are in line with current best practices for radiation dose reduction in medical imaging , which aim to balance the need for high-quality diagnostic images with the need to minimize potential risks associated with radiation exposure ( Wang et al ., 2019 ).
It was also observed that a higher pitch factor was utilized for the younger age group , which can help to reduce the radiation dose to the patient ( Kalra et al ., 2020 ).
All dose descriptors had lowest values for youngest age group ( G1 ) and highest values for oldest age group ( G3 ). Also , Karim et al . ( 2021 ), Gao et al . ( 2018 ), Galanski et al . ( 2005 ), and Mohammadbeigi et al . ( 2019 ) reported that CTDI vol and DLP had lowest values in youngest pediatric group and highest values in oldest pediatric group . In Admontree et al . ( 2019 ) study , the oldest age group did not have the highest values of CTDI vol . Instead , they found that the highest CTDI vol value