title: THE EFFECT OF BACKGROUND SIGNAL AND ITS REPRESENTATION IN DECONVOLUTION OF EPR SPECTRA ON ACCURACY OF EPR DOSIMETRY IN BONE.
abstract: This study is about the accuracy of EPR dosimetry in bones based on deconvolution of the experimental spectra into the background (BG) and the radiation-induced signal (RIS) components. The model RIS's were represented by EPR spectra from irradiated enamel or bone powder; the model BG signals by EPR spectra of unirradiated bone samples or by simulated spectra. Samples of compact and trabecular bones were irradiated in the 30-270 Gy range and the intensities of their RIS's were calculated using various combinations of those benchmark spectra. The relationships between the dose and the RIS were linear (R2> 0.995), with practically no difference between results obtained when using signals from irradiated enamel or bone as the model RIS. Use of different experimental spectra for the model BG resulted in variations in intercepts of the dose-RIS calibration lines, leading to systematic errors in reconstructed doses, in particular for high- BG samples of trabecular bone. These errors were reduced when simulated spectra instead of the experimental ones were used as the benchmark BG signal in the applied deconvolution procedures.
authors.affiliation: Department of Physics and Biophysics, Medical University of Gdansk, Debinki 1, 80-211 Gdansk, Poland bciesiel@gumed.edu.pl.
authors.forename: Bartlomiej
authors.initials: B
authors.lastname: Ciesielski
authors.affiliation: Department of Physics and Biophysics, Medical University of Gdansk, Debinki 1, 80-211 Gdansk, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Marciniak
authors.affiliation: Department of Physics and Biophysics, Medical University of Gdansk, Debinki 1, 80-211 Gdansk, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Zientek
authors.affiliation: Department of Physics and Biophysics, Medical University of Gdansk, Debinki 1, 80-211 Gdansk, Poland.
authors.forename: Karolina
authors.initials: K
authors.lastname: Krefft
authors.affiliation: Department of Physics and Biophysics, Medical University of Gdansk, Debinki 1, 80-211 Gdansk, Poland.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Cieszyński
authors.affiliation: Department of Physics and Biophysics, Medical University of Gdansk, Debinki 1, 80-211 Gdansk, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Boguś
authors.affiliation: Department of Oncology and Radiotherapy, Medical University of Gdansk, Debinki 7, 80-211 Gdansk, Poland.
authors.forename: Anita
authors.initials: A
authors.lastname: Prawdzik-Dampc
mesh_terms: D000465:Algorithms; D016477:Artifacts; D001417:Background Radiation; D001681:Biological Assay / Q000379:methods*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D006801:Humans; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000032:analysis*; D011874:Radiometry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014070:Tooth / Q000737:chemistry / Q000528:radiation effects*