BACKGROUND Application of less toxic normoxic polymer gel of N-isopropyl acrylamide (NIPAM) for radiation therapy has been studied in recent years. AIM In the current study the optical and NMR properties of NIPAM were studied for radiation therapy dosimetry application. MATERIALS AND METHODS NIPAM normoxic polymer gel was prepared and irradiated by 9 MV photon beam of a medical linac. The o...

Introduction: Electronic portal imaging devices (EPIDs) could potentially be useful for intensity-modulated radiation therapy (IMRT) and VMAT QA. The data density, high resolution, large active area, and efficiency of the MV EPID make it an attractive option. However, EPIDs were designed as imaging devices, not dosimeters, and as a result they do not inherently measure dose in ...

We report the fabrication and characterization of a photonic crystal fiber (PCF) having a sol-gel core doped with ionic copper. Optical measurements demonstrate that the ionic copper is preserved in the silica glass all along the preparation steps up to fiber drawing. The photoluminescence results clearly show that such an ionic copper-doped fiber constitutes a potential candidate for UV-C (200...

A gelatin phantom containing an optically scattering funnel-shaped region of elevated optical density (OD) was used to examine light-scattering-induced artefacts in a cone-beam optical CT scanner used for gel dosimetry. To simulate polymer gel dosimeters, the opacity was introduced by adding a colloidal scatterer to the gelatin. Scatter results in an underestimate of OD (hence dose). In line pr...

Abstract Fricke gel dosimeters were prepared using a matrix based on poly(vinyl-alcohol) chemical cross-linked with glutaraldehyde and loaded Xylenol Orange. The samples irradiated gamma rays to doses in the range of 5–30 Gy consequent color changes investigated by spectrophotometric colorimetric techniques. Starting from measurement transmittance spectra, an analysis was carried out considerin...

This paper explores the combination of cone beam optical computed tomography with an N-isopropylacrylamide (NIPAM)-based polymer gel dosimeter for three-dimensional dose imaging of small field deliveries. Initial investigations indicate that cone beam optical imaging of polymer gels is complicated by scattered stray light perturbation. This can lead to significant dosimetry failures in comparis...

A new three-dimensional dosimetry technique using x-ray computed tomography (CT) to analyse polymer gels is proposed. The CT imaging is sensitive to radiation-induced density changes that occur within irradiated polyacrylamide gel (PAG). In this preliminary study, a CT imaging protocol is developed to optimize CT images of PAG; the response of PAG CT number to dose (N(CT)-dose response) and the...