Radiation dose to the eye lens from the CT portion of a PET/CT examination and possibilities of its reduction

Authors: Jaroslav Ptáček () 1,2,3;  Pavel Koranda () 2;  Iva Metelková () 2,3
Authors‘ workplace: Oddělení lékařské fyziky a radiační ochrany, Fakultní nemocnice Olomouc 1;  Klinika nukleární medicíny LF UP a Fakultní nemocnice Olomouc 2;  Ústav zobrazovacích metod FZV UP Olomouc 3
Published in: NuklMed 2012;1:63-67
Category: Original Article


PET/CT examination is vital for oncological patients nowadays. ICRP in its document Statement on Tissue Reactions ref 4825-3093-1464 proposes a new threshold of radiation absorbed dose in an eye lens for radiation induced cataract in the level of 500 mGy. It could be possible to achieve this value in a current clinical practice (especially during repeated CT examinations of a head). The goal of our study is to provide information about radiation dose to the eye lens from the CT portion of a PET/CT examination including possibilities of its reduction.

Material and methods:
We analyzed radiation absorbed dose to the eye lens in patients evaluated with a PET/CT in the Department of Nuclear Medicine of the University Hospital in Olomouc. Absorbed dose in the eye lens was determined for a PET/CT of a torso, brain, whole-body and for the CT used for attenuation correction. We evaluated 8 patients for calculation the dose from a torso and a whole-body examination including a head, respectively. Only one study was used for the dose calculation during a brain examination and an attenuation correction, respectively.

Eye lens radiation absorbed dose calculated by ImPACT program was 6 mGy, 3.7 mGy, 49 mGy and 1.4 mGy during examination of a torso, whole-body, brain and during attenuation correction examination, respectively.

Our calculated values are in accordance with a literature. The highest eye lens radiation absorbed dose is from the brain examination. However, like in ther cases, it is still far under the threshold for a radiation induced cataract.

Key Words:
PET/CT, radiation absorbed dose, eye lens


1. ICRP. Statement on Tissue Reactions. 2011; ICRP ref 4825-3093-1464

2. Klener V (ed.). Principy a praxe radiační ochrany. Praha, Státní úřad pro jadernou bezpečnost, 2000

3. Schilham A, van der Molen AJ, Prokop M et al. Overranging at Multisection CT: An Underestimated Source of Excess Radiation Exposure. RadioGraphics 2010;30:1057-1067

4. Rehani MM, Berry M. Radiation doses in computed tomography. The Increasing doses of radiation need to be controlled. BMJ 2000;320:593-4

5. Task Group on Control of Radiation Dose in Computed Tomography, Managing patient dose in computed tomography: a report of the International Commission on Radiological Protection. Ann ICRP 2000;30:7-45

6. Zammit-Maempel I, Chadwick CL, Willis SP. Radiation dose to the lens of eye and thyroid gland in paranasal sinus multislice CT. BJR 2003;76:418-420

7. Bassim MK, Ebert CS, Sit RC et al. Radiation Dose to the Eye and Parotids During CT of the Sinuses. Otolaryngology-Head and Neck Surgery 2005;133:531-533

8. Conhen M, Wittsack HJ, Assadi S, et al. Radiation Exposure of Patients in Comprehensive Computed Tomography of the Head in Acute Stroke. Am J Neuroradiol 2006;27:1741-1745

9. Tan JSP, Tan KL, Lee JCL et al. Comparison of Eye Lens Dose on Neuroimaging Protocols between 16- and 64-Section Multiditector CT: Achieving the Lowest Possible Dose. Am J Neuroradiol 2009;30:373-377

10. Jaffe TA, Hoang JA, Yoshizumi TT et al. Radiation Dose for Routine Clinical Adult Brain CT: Variability on Different Scanners at One Institution. AJR 2010;195:433-438

11. Michel M, Jacob S, Roger G et al. Eye lens radiation exposure and repeated head CT scans: A problem to keep in mind. Eur J Radiol 2011, doi:10.1016/j.ejrad.2011.03.051

12. Hall P, Granath F, Lundell M et al. Lenticular opacitites in individuals exposed to ionizing radiation in infancy. Radiat Res 1999;152:190-5

13. Rehani MM, Vano E, Ciraj-Bielac O et al. Radiation and cataract. Radiat Prot Dosimetry 2011;147(1-2):300-304

14. Chiewvit P, Ananwattanasuk J, Mongkolsuk M et al. Evaluation of Image Quality and Len`s Radiation Dose of a Low-Dose Cranial CT Scan. J Med Assoc Thai 2009;92(6):831-5

15. Niu Y, Wang Z, Liu Y et al. Radiation Dose to the Lens Using Different Temporal Bone CT Scanning Protocols. Am J Neuroradiol 2010;31:226-229

16. Recommendation by the German Commission on Radiological Protection. Patient Radiological Protection in Cranial Computed Tomography (Gantry Tilt) [online]. April 2011. [cit. 2012-11-08]. Dostupné na: http://www.ssk.de/SharedDocs/Beratungsergebnisse_PDF/2011/2011_03e.pdf?__blob=publicationFile

17. McLaughlin DJ, Mooney RB. Dose reduction to radiosensitive tissues in CT. Do commercially available shields meet the users’ needs? Clinical Radiology 2004;59:446-450

18. Mukundan S, Wang PI, Frush DP et al. MOSFET Dosimetry for Radiation Dose Assessment of Bismuth Shielding of the Eye in Children. Am J Radiol 2007;188:1648-1650

19. Raissaki M, Perisinakis K, Damilakis J et al. Eye-lens bismuth shielding in paediatric head CT: artefact evaluation and reduction. Pediatr Radiol 2010;40:1748-1754

20. Zizka J, Jandura J, Kvasnicka T et al. Reduction of effective and organ dose to the eye lens in cerebral MDCT scans using iterative image reconstruction [online]. [cit. 2012-11-08]. Dostupné na: http://www.rsna.org/uploadedFiles/RSNA/Content/News/NewsArticle/2012/July/ECR2012_CT_brain_Zizka.ppt

Nuclear medicine Radiodiagnostics Radiotherapy
Forgotten password

Don‘t have an account?  Create new account

Forgotten password

Enter the email address that you registered with. We will send you instructions on how to set a new password.


Don‘t have an account?  Create new account