H. Murat et al.: Radioprotection 2025, 60( 1), 65 – 75 73
The differences in LAR values observed in different organs and between men and women are consistent with the patterns seen in the BEIR VII phase II report. For instance, our findings indicate higher LAR values in thyroid and lung tissues, particularly in women, which is consistent with the genderspecific susceptibilities discussed in the BEIR VII phase II report. These observations are reinforced by the age at exposure and gender demographics of our cohort, where differences in metabolic activity and hormonal influences at different age at exposure might affect radionuclide distribution in organs( Alameen et al., 2021; Sprinz et al., 2018). Furthermore, research has demonstrated that some organs are more radiosensitive, such as the thyroid and breast, particularly in females( National Research Council, 2006). Figure 2 in the results section shows a more detailed understanding of the relationship between PET examinations and LAR cancer incidence risk. This figure highlights the importance of age at exposure and gender as key factors in evaluating radiation risk. The used of the 3 rd order polynomial approach is justified in providing a closer approximation to the observed data patterns where risk changes from younger to older age at exposure. Studies like( Brenner, 2012) have shown that age at exposure significantly impacts radiation-related cancer risks, particularly in younger populations, where the cancer risk can be significantly higher( Brenner, 2012).
We acknowledge the limitation of our study due to the lack of baseline cancer rates data for Asian populations that could substitute the American population data. Future research should strive to incorporate the local population data to analyze the impact of demographic factors on radiation risks. Furthermore, our analysis of the radiation risks from PET examinations did not include data on organ absorbed doses from the CT component which are crucial for a comprehensive evaluation of total radiation exposure. The lack of this data might compromise the precision of our risk assessment, as the CT component often accounts for a significant contribution for the total dose. To address these limitations, future studies should focus on obtaining detailed measurements of organ absorbed doses from both PET and CT components and also evaluate the LAR of cancer incidence by considering the local cancer baseline rates.
5 Conclusion In summary, our findings show that the E of whole-body 18 F-FDG PET / CT examinations vary from 3.2 mSv to
27.3 mSv, and the LAR of cancer incidence among men and women is 7 and 8 cases per 100,000 persons exposed to 0.1 Gy, respectively. It is important to note that these data only represent the PET component, and the radiation risk may be higher when taking into account the organ dose from the CT component. Despite this, there is an increasing demand for whole-body 18 F-FDG PET / CT examinations in oncology studies. To ensure radiation safety and improve image quality, protocols should be optimized with advanced image processing techniques, and appropriate image reconstruction parameters.
Funding
The authors are grateful to the Ministry of Higher Education( Malaysia)( MOHE) and Universiti Putra Malaysia with grant number FRGS / 1 / 2020 / STG07 / UPM / 02 / 3.
Conflicts of interest
The author( s) declare( s) that there is no conflict of interest.
Data availability statement
The data are not publicly accessible as they contain information that could compromise the privacy of research participants.
Ethics approval
This study was approved by the Medical Research and Ethics Committee( MREC) of the Ministry of Health Malaysia( MOH), which waived patient consent forms for the retrospective analysis with the approval ID; NMRR-18-1176-41991.
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