TISSUE EQUIVALENCE STUDY AND EVALUATION OF A NORMOXIC POLYMER GEL DOSIMETER

NADJLA BOURBIA

Laboratory for the Study of Electronic Materials for Medical Applications; Mathematical Physics and Subatomic Physics Laboratory, Mentouri Brothers University, Constantine 1, Algeria

We determined the mass fractions, density, attenuation coefficients, effective atomic number (Zeff) and stopping power of MAGAT gel to verify its equivalence to water and tissue. We also studied the MAGAT gel response using the X-ray scanner, using a new MAGAT gel dosimeter with different concentrations of components (gelatin 8 %, methacrylic acid 6 % methacrylic acid, gelatin, tetrakis (hydroxymethyl) phosphonium chloride (THPC) 2 mM, water 86 %). We observed a small difference in the mass fraction due to the change in concentration of some main chemical compounds of MAGAT gel. The MAGAT gel has a Zeff almost identical to water. The curves of mass attenuation coefficient (μ/ρ) of water and MAGAT gel as a function of energy present a relative deviation not exceeding 4 %. The relative difference between the two stopping power curves is less than 0.5 %. The response of our novel MAGAT gel to the X-ray CT scanner as a function of the dose is linear with dose sensitivity equal to 1.85±0.28 HU Gy−1, while the concentrations of its components have a better tissue equivalence and a high NCT dose response.

Key words: Gel polymer, MAGAT, radiobiological equivalence, X-ray scanner

e-mail: bourbia_nejla@yahoo.fr

 

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