Acute phase response during radiotherapy

The effective management of radiological emergencies where members of the public not carrying conventional dosimeter have been exposed to doses of ionising radiation requires individual dose estimates to support medical triage. Biological and physical methods have been developed to address this issue. New materials and techniques have been sought to reinforce preparedness for such emergencies. Alternative materials, such as clothing, shoes, paper, plastic items, nail polish or banknotes were investigated using thermoluminescence (TL) and optically stimulated luminescence (OSL).
 Most of the materials and fabric tested exhibited either no detectable response to dose using luminescence technique, or a weak response yielding detection limits above 2 Gy, with the exceptions of a blue polyester fabric responding to infra-red stimulated luminescence (IRSL) and some types of polymer-based fabric that were found to have luminescence favourable characteristics for short - term dosimetry and particularly those containing mineral fillers.
 The most promising were fabrics containing calcium carbonate fillers, where the TL response to β radiations was measured with a detection limit as low as 4 mGy, and a relatively low native signal in the region of interest (≤ 200 °C). The fading was found to be slower for samples stored at -15 °C compared with samples stored at ambient temperature. A blind test was carried out and confirmed the potential of bags containing calcium carbonate fillers to provide reliable dose estimate for radiological triage. Furthermore, the TL signal of calcium carbonate fillers contained in the fabric of bags offers several advantages for accident dosimetry compared with other methods, such as a rapid dose assessment, the low cost value of the material and availability, and the possibility to map radiological doses is the fabric covers sufficient surface.

New fortuitous materials for luminescence dosimetry following radiological emergencies

Brain Haemorrhage Detection Through SVM Classification of Electrical Impedance Tomography Measurements -- Brain and Human Body Modeling: Computational Human Modeling at EMBC 2018

Currently there is no in vitro testing of glioblastoma biopsy material to assess tumour sensitivity to radiation, which could form a basis for personalised treatment plans for patients. In this work, a model to predict sensitivity to radiation, via the micronucleus assay, is set out and a proof of concept is presented where numbers of micronuclei in a glioblastoma cell line, LN18 is predicted. 
One key requirement for the model is that any in vitro testing needs to yield results within a few days, as the timeline for glioblastoma patients from diagnosis to treatment is short. In order to achieve this, a flow cytometry technique is assessed against traditional fluorescence microscopy for detection of micronuclei. 

Flow cytometry was completed using an in vitro Microflow kit from Litron Laboratories. There was no previous experience using this kit in cancerous cell lines and limited experience in cell lines that adhere to their flask’s surface as the kit is used mostly in peripheral blood lymphocytes. 

The flow cytometry technique can be completed within the required time frame and is much less labour intensive that fluorescence microscopy. However, there is a significant amount of variance between samples which makes the microscopy results more useful for fitting the modelling work to. It is expected with further experience and use of the supplied template, as this was incompatible at the time of the experiments, will play a role in reducing some of the variance.

The model, in its current state of development, is able to predict numbers of micronuclei in a cohort of cells following doses of radiation between 1 and 3 Gy. The numerical solution is based on a decision tree structure where each double strand break that would be caused by radiation is run through the tree. The tree is traversed populated using probabilities for each decision, such as the success of a repair pathway, and Monte Carlo methods for predicting the cohort response to radiation. These probabilities are fitted to experimental data. 

The prediction of micronuclei is the first step for the MiNiMUS model. Future work should prioritise incorporating cell death into the model and further assessing the suitability of flow cytometry for rapid micronuclei detection.

MiNiMUS : a model to predict the formation and numbers of micronuclei in cells.

................................................................................................................................................... 6 Statement of originality ........................................................................................................................... 7 Acknowledgements .................................................................................................................................. 8 Definitions ................................................................................................................................................ 9 Terminology ............................................................................................................................................. 9 1 Chapter 1Introduction ................................................................................................................. 10 1.

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A Systematic Study of Quartz Thermoluminescence for Forensic and Retrospective Dosimetry

The current focus on networking and mutual assistance in the management of radiation accidents or incidents has demonstrated the importance of a joined-up approach in physical and biological dosimetry. To this end, the European Radiation Dosimetry Working Group 10 on 'Retrospective Dosimetry' has been set up by individuals from a wide range of disciplines across Europe. Here, established and emerging dosimetry methods are reviewed, which can be used immediately and retrospectively following external ionising radiation exposure. Endpoints and assays include dicentrics, translocations, premature chromosome condensation, micronuclei, somatic mutations, gene expression, electron paramagnetic resonance, thermoluminescence, optically stimulated luminescence, neutron activation, haematology, protein biomarkers and analytical dose reconstruction. Individual characteristics of these techniques, their limitations and potential for further development are reviewed, and their usefulness in specific exposure scenarios is discussed. Whilst no single technique fulfils the criteria of an ideal dosemeter, an integrated approach using multiple techniques tailored to the exposure scenario can cover most requirements.

Chumak

Papers

Retrospective dosimetry techniques for external ionising radiation exposures