Whole-body fluorine-18-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) has been mostly recognized for managing oncologic patients. However, there is a growing concern over the radiation exposure of patient undergoing PET/CT due to higher radiation dose compared to other imaging modalities. Diagnostic reference level (DRL) can be used as a tool to optimize the use of radiological imaging procedure in a way that suits the health needs and reduce radiation exposure while maintaining image quality. The aim of this study is to establish a local DRL received by adult patients that undergone a whole-body ¹⁸F-FDG PET/CT at Sunway Medical Centre. Dose data such as activity, ED_PET, CTDI_vol, DLP, ED_CT and ED_cumulated were retrospectively collected for 300 patients each for both PET/CT uMI 780 (System I) and PET/CT Biograph mCT 20 Excel (System II). The 75th percentile of dose distribution were calculated and compared with other established DRLs. DRL for ED_PET, CTDI_vol, DLP, ED_CT and ED_cumulated for System I were 175.96 MBq, 3.34 mSv, 1.86 mGy, 1854.34 mGy cm, 27.76 mSv and 31.13 mSv while for System II were 212.35 MBq, 4.03 mSv, 12.48 mGy, 1198 mGy cm, 17.55 mSv and 21.83 mSv, respectively. There is signifant difference for both PET and CT dose value between PET/CT (p-value <0.05). Our DRL showed that the ¹⁸F-FDG activity dose was the lowest while the CTDI_vol and DLP were the highest among the other established DRLs. The local DRL for whole-body ¹⁸F-FDG PET/CT is established.

1. Abe, K., Hosono, M., Igarashi, T., Iimori, T., Ishiguro, M., Ito, T., Nagahata, T., Tsushima, H., & Watanabe, H. (2020). The 2020 national diagnostic reference levels for nuclear medicine in Japan. Annals of Nuclear Medicine, 34(11), 799–806. https://doi.org/10.1007/s12149-020-01512-4
2. Alameen, S., Alqahtani, M., Al-Mohammed, H. I., & Too, S. (2021). Radiobiological risks in terms of effective dose and organ dose from 18F-FDG whole-body PET/CT procedures. Saudi Journal of Biological Sciences, 28(11), 6337–6344. https://doi.org/10.1016/j.sjbs.2021.06.096
3. Alessio, A. M., Suleiman, O. H., Rehani, M. M., Strauss, K. J., Samei, E., Mahesh, M., Hedrick, W. R., & Royal, H. D. (2015). Role of reference levels in nuclear medicine: A report of the SNMMI dose optimization task force. Journal of Nuclear Medicine, 56(11), 1802–1809. https://doi.org/10.2967/jnumed.114.148155
4. Alkhybari, E. M., McEntee, M. F., Brennan, P. C., & Reed, W. M. (2018). Determining and updating PET/CT and SPECT/CT diagnostic reference levels: A systematic review. Radiation Protection Dosimetry, 182(4), 514–525. https://doi.org/10.1093/rpd/ncy101
5. Avramova-Cholakova, S., Ivanova, A., Garcheva, M., Petrova, J., & Vassileva, J. (2015). Patient doses from pet-CT procedures. Radiation Protection Dosimetry, 165(1-4), 430–433. https://doi.org/10.1093/rpd/ncv056
6. Bebbington, N. A., Haddock, B. T., Bertilsson, H., Hippeläinen, E., Husby, E. M., Tunninen, V. I., & Söderberg, M. (2019). A Nordic survey of CT doses in hybrid PET/CT and SPECT/CT examinations. EJNMMI Physics, 6(1), Article 26. https://doi.org/10.1186/s40658-019-0266-7
7. Beyer, T., Townsend, D. W., Brun, T., Kinahan, P. E., Charron, M., Roddy, R., Jerin, J., Young, J., Byars, L., & Nutt, R. (2000). A combined PET/CT scanner for clinical oncology. Journal of Nuclear Medicine, 41(11), 1803–1812.
8. Bontranger, K. L., & Lampignano, J. P. (2014). Textbook of radiographic positioning and related anatomy (8th ed.). Elsevier Health Sciences.
9. Brix, G., Lechel, U., Glatting, G., Ziegler, S. I., Münzing, W., Becker, S. P., Jessen, K. A., & Reiners, C. (2005). Radiation exposure of patients undergoing whole-body dual-modality 18F-FDG PET/CT examinations. Journal of Nuclear Medicine, 46(4), 608–615.
10. Chan, H. P., Shie, M. S., Wu, J. C., Chen, J. C., & Chen, Y. C. (2020). Comparison of FDG-PET/CT for cancer detection in populations with different risks of underlying malignancy. In Vivo, 34(4), 2137–2142. [suspicious link removed]
11. Chan, V. O., McDermott, S., Buckley, O., Allen, S., Casey, M., Launders, J., & Torreggiani, W. C. (2012). The relationship of body mass index and abdominal fat on the radiation dose received during routine computed tomographic imaging of the abdomen and pelvis. Canadian Association of Radiologists Journal, 63(4), 260–266. https://doi.org/10.1016/j.carj.2011.02.003
12. Changmuang, W., Thamnuson, P., & Chamroonrat, W. (2016). Evaluation of effective dose and cancer risk associated with low dose protocols dual-modality 18 F-FDG PET/CT examinations. Journal of Siriraj Radiology, 1(1), 12–21.
13. Delcroix, O., De Just, S., Rust, E., Detour, J., Imperiale, A., & Addeo, P. (2021). Assessment of image quality and lesion detectability with digital PET/CT system. Frontiers in Medicine, 8, Article 674140. https://doi.org/10.3389/fmed.2021.674140
14. Dhalisa, H., Sulieman, A., Alkhorayef, M., & Bradley, D. A. (2016). Radiation assessment to paediatric with F-18-FDG undergo whole-body PET/CT examination. AIP Conference Proceedings, 1704(1), Article 050013. https://doi.org/10.1063/1.4940108
15. Etard, C., Celier, D., Roch, P., & Aubert, B. (2012). National survey of patient doses from whole-body FDG PET-CT examinations in France in 2011. Radiation Protection Dosimetry, 152(4), 344–349. https://doi.org/10.1093/rpd/ncs114
16. Harrison, J. D., & Streffer, C. (2008). Radiation doses and risks from internal emitters. Journal of Radiological Protection, 28(2), 137–159. https://doi.org/10.1088/0952-4746/28/2/R01
17. Harrison, J. D., Streffer, C., & Cox, R. (2007). The ICRP protection quantities, equivalent and effective dose: Their basis and application. Radiation Protection Dosimetry, 127(1-4), 13–18. https://doi.org/10.1093/rpd/ncm244
18. Hatami, S., Schuchardt, C., & Mueller, S. P. (2020). Added value of digital over analog PET/CT: More significant as image field of view and body mass index increase. Journal of Nuclear Medicine Technology, 48(4), 316–322. https://doi.org/10.2967/jnmt.120.243550
19. Huang, B., Law, M. W. M., & Khong, P. L. (2009). Whole-body PET/CT scanning: Estimation of radiation dose and cancer risk. Radiology, 251(1), 166–174. https://doi.org/10.1148/radiol.2511081300
20. International Commission on Radiological Protection. (1977). Recommendations of the International Commission on Radiological Protection (ICRP Publication 26). Pergamon Press.
21. International Commission on Radiological Protection. (2007). The 2007 Recommendations of the International Commission on Radiological Protection (ICRP Publication 103). Elsevier.
22. International Commission on Radiological Protection. (2008). Radiation dose to patients from radiopharmaceuticals: A third addendum to ICRP Publication 53 (ICRP Publication 106). Elsevier.
23. Israel, G. M., Cicchiello, L., Brink, J., & Egbert, M. (2010). Patient size and radiation exposure in thoracic, pelvic, and abdominal CT examinations performed with automatic exposure control. American Journal of Roentgenology, 195(6), 1342–1346. https://doi.org/10.2214/AJR.10.4419
24. Jallow, N., Robinson, L. E., & Ward, R. C. (2016). Diagnostic reference levels of CT radiation dose in whole-body PET/CT. Journal of Nuclear Medicine, 57(Suppl. 2), 2631.
25. Jelercic, S., Rajer, M., & Tomic, S. (2015). The role of PET-CT in radiotherapy planning of solid tumours. Radiology and Oncology, 49(1), 1–9. https://doi.org/10.2478/raon-2014-0046
26. Kamal, I., Sulieman, A., Al-Mohammed, H. I., & Alkhorayef, M. (2020). The effective dose estimation of patients administered with 18F-FDG and Ga-68 DOTATATE in PET/CT examination associated with gender and weight. Physics in Technology and Medicine, 1(1), 45–52.
27. Kanal, K. M., Butler, P. F., Sengupta, D., Bhargavan-Marek, M., Coombs, L. P., & Morin, R. L. (2017). U.S. diagnostic reference levels and achievable doses for 10 adult CT examinations. Radiology, 284(1), 120–133. https://doi.org/10.1148/radiol.2017161911
28. Kaushik, A., Jaimini, A., Tripathi, M., D'Souza, M., Sharma, R., Mondal, A., & Mishra, A. K. (2015). Estimation of radiation dose to patients from 18FDG whole body PET/CT investigations using dynamic PET scan protocol. Indian Journal of Medical Research, 142(6), 721–731. https://doi.org/10.4103/0971-5916.174564
29. Kluetz, P. G., Meltzer, C. C., Villemagne, V. L., Kinahan, P. E., Chander, S., Martin, T., & Townsend, D. W. (2000). Combined PET/CT imaging in oncology: Impact on patient management. Clinical Positron Imaging, 3(6), 223–230. https://doi.org/10.1016/S1095-0397(01)00055-3
30. Li, Y., Wang, J., & Zhang, Y. (2019). Effective radiation dose of 18F-FDG PET/CT: How much does diagnostic CT contribute? Radiation Protection Dosimetry, 185(2), 182–189. https://doi.org/10.1093/rpd/ncy203
31. Lima, T. V. M., Gnesin, S., Ryckx, N., Stutz, B., Verdun, F. R., & Baechler, S. (2018). Swiss survey on hybrid imaging CTs doses in Nuclear Medicine and proposed national dose reference levels. Zeitschrift für Medizinische Physik, 28(4), 265–275. https://doi.org/10.1016/j.zemedi.2017.09.006
32. Lin, E. C. (2010). Radiation risk from medical imaging. Mayo Clinic Proceedings, 85(12), 1142–1146. https://doi.org/10.4065/mcp.2010.0260
33. Paiva, F. G., Ramos, P. M., & Silva, A. M. (2019). Evaluation of patient effective dose in a PET/CT test. Applied Radiation and Isotopes, 153, Article 108842. https://doi.org/10.1016/j.apradiso.2019.108842
34. Specht, L., & Yahalom, J. (2018). PET/CT in radiation therapy planning. Seminars in Nuclear Medicine, 48(3), 201–207. https://doi.org/10.1053/j.semnuclmed.2018.02.001
35. Wachabauer, D., Shamiyeh, H. L., & Schmitzer, C. (2022). Diagnostic Reference Levels for nuclear medicine imaging in Austria: A nationwide survey of used dose levels for adult patients. Zeitschrift für Medizinische Physik, 32(2), 134–146. https://doi.org/10.1016/j.zemedi.2021.03.003