The impact of circadian rhythms on medical imaging and radiotherapy regimes for the paediatric patient

Daily rhythmic changes are found in cellular events in cell cycle, DNA repair, apoptosis and angiogenesis in both normal and tumour tissue, as well as in enzymatic activity and drug metabolism. In this paper, we hypothesize that circadian rhythms need to be considered in radiation protection and optimization in personalized medicine, especially for paediatric care. The sensitivity of the eye lens to ionizing radiation makes the case for limiting damage to the lens epithelium by planning medical radio-imaging procedures for the afternoon, rather than the morning. Equally, the tumour and normal tissue response to radiotherapy is also subject to diurnal variation enabling optimization of time of treatment

Radiological impact of naturally occurring radionuclides in bottled water

Consumption of bottled water is increasing year after year in Europe. Due to the local geology from where the water is extracted; bottled water could be enhanced with radionuclides. This study focuses on the activity concentrations of 210Po, 210Pb, 226Ra, 228Ra, 234U and 238U in bottled water available in the Swedish market, to assess the radiological impact to different age groups. The results showed that among the 26 brands studied, only three could exceed the threshold value for drinking water: 0.1 mSv/year. For two brands, the dose was mainly due to the activity concentrations of 238U and 234U being up to 714 and 1162 mBq/L, respectively. While for one brand, the dose was mainly due to the activity concentration of both 210Po and 210Pb being around 100 mBq/L. For the remainder brands, 228Ra was the main contributor to the committed effective dose

Transcriptional response of kidney tissue after 177Lu-octreotate administration in mice

AbstractIntroductionThe kidneys are one of the main dose limiting organs in 177Lu-octreotate therapy of neuroendocrine tumors. Therefore, biomarkers for radiation damage would be of great importance in this type of therapy. The purpose of this study was to investigate the absorbed dose dependency on early transcriptional changes in the kidneys from 177Lu-octreotate exposure.MethodsFemale Balb/c nude mice were i.v. injected with 1.3, 3.6, 14, 45 or 140MBq 177Lu-octreotate. The animals were killed 24h after injection followed by excision of the kidneys. The absorbed dose to the kidneys ranged between 0.13 and 13Gy. Total RNA was extracted from separated renal tissue samples, and applied to Illumina MouseRef-8 Whole-Genome Expression Beadchips to identify regulated transcripts after irradiation. Nexus Expression 2.0 and Gene Ontology terms were used for data processing and to determine affected biological processes.ResultsDistinct transcriptional responses were observed following 177Lu-octreotate administration. A higher number of differentially expressed transcripts were observed in the kidney medulla (480) compared to cortex (281). In addition, 39 transcripts were regulated at all absorbed dose levels in the medulla, compared to 32 in the cortex. Three biological processes in the cortex and five in the medulla were also shared by all absorbed dose levels. Strong association to metabolism was found among the affected processes in both tissues. Furthermore, an association with cellular and developmental processes was prominent in kidney medulla, while transport and immune response were prominent in kidney cortex.ConclusionSpecific biological and dose-dependent responses were observed in both tissues. The number of affected transcripts and biological processes revealed distinct response differences between the absorbed doses delivered to the tissues