| Title: | Breath markers for therapeutic radiation |
| Author(s): | Salman D; Eddleston M; Darnley K; Nailon WH; McLaren DB; Hadjithelki A; Ruszkiewicz D; Langejuergen J; Alkhalifa Y; Phillips I; Thomas CLP; |
| Address: | "Centre for Analytical Science, Chemistry, Loughborough University, Loughborough, United Kingdom. Pharmacology, Toxicology & Therapeutics Unit, University of Edinburgh, Edinburgh, United Kingdom. Edinburgh Cancer Centre, NHS Lothian, Edinburgh, United Kingdom. Computer Science, Loughborough University, Loughborough, United Kingdom" |
| ISSN/ISBN: | 1752-7163 (Electronic) 1752-7155 (Linking) |
| Abstract: | "Radiation dose is important in radiotherapy. Too little, and the treatment is not effective, too much causes radiation toxicity. A biochemical measurement of the effect of radiotherapy would be useful in personalisation of this treatment. This study evaluated changes in exhaled breath volatile organic compounds (VOC) associated with radiotherapy with thermal desorption gas chromatography mass-spectrometry followed by data processing and multivariate statistical analysis. Further the feasibility of adopting gas chromatography ion mobility spectrometry for radiotherapy point-of-care breath was assessed. A total of 62 participants provided 240 end-tidal 1 dm(3) breath samples before radiotherapy and at 1, 3, and 6 h post-exposure, that were analysed by thermal-desorption/gas-chromatography/quadrupole mass-spectrometry. Data were registered by retention-index and mass-spectra before multivariate statistical analyses identified candidate markers. A panel of sulfur containing compounds (thio-VOC) were observed to increase in concentration over the 6 h following irradiation. 3-methylthiophene (80 ng.m(-3) to 790 ng.m(-3)) had the lowest abundance while 2-thiophenecarbaldehyde(380 ng.m(-3) to 3.85 mug.m(-3)) the highest; note, exhaled 2-thiophenecarbaldehyde has not been observed previously. The putative tumour metabolite 2,4-dimethyl-1-heptene concentration reduced by an average of 73% over the same time. Statistical scoring based on the signal intensities thio-VOC and 3-methylthiophene appears to reflect individuals' responses to radiation exposure from radiotherapy. The thio-VOC are hypothesised to derive from glutathione and Maillard-based reactions and these are of interest as they are associated with radio-sensitivity. Further studies with continuous monitoring are needed to define the development of the breath biochemistry response to irradiation and to determine the optimum time to monitor breath for radiotherapy markers. Consequently, a single 0.5 cm(3) breath-sample gas chromatography-ion mobility approach was evaluated. The calibrated limit of detection for 3-methylthiophene was 10 mug.m(-3) with a lower limit of the detector's response estimated to be 210 fg.s(-1); the potential for a point-of-care radiation exposure study exists" |
| Keywords: | Aged Biomarkers/*analysis Breath Tests/*methods Calibration Exhalation Female Gas Chromatography-Mass Spectrometry Humans Male Middle Aged Principal Component Analysis *Radiation Volatile Organic Compounds/analysis; |
| Notes: | "MedlineSalman, Dahlia Eddleston, Michael Darnley, Kareen Nailon, William H McLaren, Duncan B Hadjithelki, Andria Ruszkiewicz, Dorota Langejuergen, Jens Alkhalifa, Yaser Phillips, Iain Thomas, C L Paul eng Research Support, Non-U.S. Gov't England 2020/10/27 J Breath Res. 2020 Oct 24; 15(1):016004. doi: 10.1088/1752-7163/aba816" |
