To the top

Page Manager: Webmaster
Last update: 9/11/2012 3:13 PM

Tell a friend about this page
Print version

The influence of circadia… - University of Gothenburg, Sweden Till startsida
To content Read more about how we use cookies on

The influence of circadian rhythm on the biodistribution of I-131

Conference contribution
Authors Charlotte Andersson
Mikael Elvborn
Johan Spetz
Britta Langen
Eva Forssell-Aronsson
Published in Swedish Radiation Research Association for Young Scientists Workshop, Stockholm, 2016, August 25-26
Publication year 2016
Published at Institute of Clinical Sciences, Department of Radiation Physics
Language en
Keywords Biodistribution, I-131, circadian rhythm, thyroid, mouse, dosimetry,
Subject categories Radiation biology, Radiological physics


Background: I-131 is well-established in nuclear medicine. The thyroid is a target organ when treating thyroid cancer with unbound I-131, but also a risk organ in I-131-based radionuclide therapy. Exposure to I-131 can also occur from the environment at nuclear accidents. Accurate knowledge of I-131 biodistribution is essential to correctly estimate the absorbed dose to organs and determine potential risks from both medical and hazard exposure. Many biological functions follow a circadian rhythm. Nevertheless, circadian rhythm remains an unknown factor in radionuclide biodistribution. Aim: The purpose of this study was to investigate if circadian rhythm affects I-131 biodistribution in mice and hence absorbed dose to mouse tissues. Methods: The radioactivity concentration in various tissues was studied at different time points after administration of I-131 and absorbed doses were calculated according to the MIRD formalism. The effect of circadian rhythm was studied by varying the time of administration. Male C57BL/6N mice were i.v. injected with I-131 at 8 am, 12 pm or 4 pm and killed after 1h to 7d. Results: Statistically significant difference in activity concentration and absorbed dose between the three injection series was observed for at least one time point after injection for many tissues. Highest activity concentration and absorbed dose were found in the thyroid. Conclusion: The results demonstrated that the biodistribution of I-131 in mice is influenced by the time of day of administration to a certain extent. These findings advocate that circadian rhythm should be considered in biodistribution studies and dose calculations.

Page Manager: Webmaster|Last update: 9/11/2012

The University of Gothenburg uses cookies to provide you with the best possible user experience. By continuing on this website, you approve of our use of cookies.  What are cookies?