120 M . Benamar et al .: Radioprotection 2024 , 59 ( 2 ), 117 – 122
The 75 th percentile values of CTDIvol and DLP per acquisition varied significantly among the three study centers ; these variations may be explained by differences in acquisition protocols used by radiology technicians , and these differences depend on the technicians ’ training and experience . A study by Tahiri suggests that effective initial and continuing training of health care staff and the implementation of referral guidelines for medical imaging could lead to improve practitioners ’ knowledge of patient radiation protection and consequently could reduce radiation dose ( Tahiri et al ., 2022 ).
The overall comparison between the 75 th percentile values resulting from our study and the values from other recent local studies and DRLs from other countries revealed a substantial average reduction , reflecting a significant improvement in the process of optimizing the dose delivered to the patient during a CT scan in our departments .
The radiation dose received by patients in all three hospitals was expressed in terms of mean CTDIvol and total DLP values . These data show that hospital examinations ( H3 ) showed the highest values . These results could be attributed to the use of a higher tube voltage ( 130 kV ) compared to the other hospitals . Considering that the kilovoltage has an effect on the dose ( Pesenti Rossi et al ., 2012 ), increasing the voltage from 120 kV to 140 kV , for instance , increases the dose by approximately 40 % ( Cordoliani & Boyer , 2004 ). In our study the abdominopelvic examinations were systematically performed with a voltage of 120 kV . However , a study recommends the use of lower tube voltages ( 80 or 100 kV ) to optimize the dose in these more vulnerable regions ( Tang et al ., 2012 ). In addition , the values of the tube current-time product should be adapted to the size of the patient , and the dose requirements of each examination type . As well as , the use of load modulation automatic with a limit value would be sufficient to reduce the patient dose and to achieve diagnostic images with a good quality .
Regarding the effective doses and renal dose received by patients during abdominopelvic CT examination in the three hospitals , the values of the effective dose were completely different for the three study hospitals , the ANOVA test revealed a significant difference between the three Hospitals in terms of effective dose ( F E eff ( mSv ) = 5.14 ; p 0.01 ). The average effective dose in Hospital H3 is much higher than the other hospitals , this variation could be attributed to the increase in the total average DLP value , this increase may be due to data acquisition conditions and especially the number of phases per examination . On the other hand , multiplying the number of scans on the same region with the same amount of radiation generally triples the transmitted energy and increases the effective dose by less than 10 % ( Ware et al ., 1999 ).
With regard to renal dose , all hospitals showed statistically significant differences ( F E k ( mSv ) = 7.01 ; p 0.01 ). However , the mean renal dose in Hospital H3 was much lower than the other hospitals . This variation could be attributed to the mean value of mAs used , which was the lowest compared to the other hospitals .
Several epidemiological studies directly support excess cancer risks associated with low-dose ionizing radiation . Furthermore , the magnitude of the cancer risks from these lowdose radiation exposures was statistically compatible with the radiation dose-related cancer risks of the atomic bomb survivors ( Michael Hauptmann et al ., 2020 ). Moreover , epidemiological studies suggest that the lowest dose of ionizing radiation for which there are good evidences of an increase in cancer risk in humans is 10 to 50 mSv for acute exposure and 50 to 100 mSv for prolonged exposure ( Yasser et al ., 2020 ; Abbott et al ., 2015 , Tubiana et al ., 2006 ).
Generally , in our work , the mean values of the effective dose and renal dose of all hospitals were 10.29 mSv and 7.56 mSv respectively . These results prompts us to continuing to improve our protocols and our professional practice associated with an awareness and qualification of operators in patient radiation protection in CT scan .
Furthermore , the results of our study showed variations in cancer risk and hereditary risk whether by abdominopelvic or the kidney and also among the various hospitals . In general , these variations are the result of differences between the effective dose values received per patient region and per hospital . In fact , cancer risk and hereditary risk are proportional to effective dose by factors of 5.5 10 �2 ( Sv �1 ) and 0.2 10 �2 ( Sv �1 ) respectively . Thus , any increase in the value of effective dose necessarily induces an increase in cancer risk and hereditary risk .
Although any effort and innovation , whether technical , material and / or computer , to optimize the dose delivered to the patient will have a positive impact on the optimal reduction of the harmful risks of ionizing radiation , education on radiation protection remains an essential point . In fact , several studies have shown that initial training as well as continuing training in radiation protection for operators remain a major issue in health facilities ( Bertho et al ., 2023 , Housni et al ., 2023 , Mohebbi et al ., 2023 ). In addition , the establishment of Diagnostic Reference Levels ( DRLs ), which are still considered an effective means of evaluating and optimizing professional practices , will significantly improve the radiation protection of the patient who is our focus ( El Mansouri et al ., 2022 , Benamar et al ., 2023 ).
5 Conclusion
The objective of this study is to assess the effective dose and the renal dose delivered to patients during an abdominopelvic examination and to estimate the associated likely stochastic effects . This works show that the doses received by patients during abdominopelvic CT examinations in the study departments are lower than those usually observed in other national and international studies . These results encourage us to continue in the process of supporting and raising the awareness of radiology operators with regard to radiation protection of professionals and patients . Our actions in this field are focused , among other things , on promoting scientific research in the area of best practices in radiation protection during the preparation of end-of-study projects for future professionals , radiology technicians and physicists .
Acknowlegments
Authors are thankful to Miss . Benamar M and Mr . Housni A , for their commitment during data collection and Analysis .
Funding This research did not receive any specific funding .