Preliminary study on a 3D lung mimicking dosimeter based on Pluronic F-127 matrix

Abstract

This work reports on the first results obtained for a new 3D lung mimicking dosimeter. The dosimeter comprises 3% (w/w) acrylamide, 3% (w/w) N,N′-methylenebisacrylamide, 10 mM tetrakis (hydroxymethyl) phosphonium chloride (THPC), 25% (w/w) poly(ethylene oxide)-block-poly (propylene oxide)-block-poly (ethylene oxide) (Pluronic F-127) in presence or absence of sodium chloride. The approach to the manufacturing of the dosimeter both in the presence of air and argon relied on the preparation of a foam using the surface-active properties of Pluronic F-127. The resistance of Pluronic F-127 matrix to irradiation was analysed using differential scanning calorimetry; however, the foam dosimeter after irradiation was measured by using Raman spectroscopy, scanning electron and optical microscopy as well as computed tomography. Preliminary investigation revealed the following: (i) sodium chloride improves the thermal properties of the foam dosimeter in a low temperature region and impacts on the foam density, (ii) the dosimeter prepared in presence and absence of air responds to irradiation, however, its dose response is improved in absence of air, (iii) the preparation method applied allowed for decreasing the density of the dosimeter relative to solid gel dosimeter towards the density of lungs tissue and lungs in exhale. The results obtained pointed to a potential of this new dosimeter in 3D radiotherapy dosimetry related to eradication of lung tumours.