Methylthymol blue in Fricke gels

8th International Conference on 3D Radiation Dosimetry

Penev, K.I.^1 ; Mequanint, K.^1,2

Department of Chemical and Biochemical Engineering, University of Western Ontario, London

ON

N6A 5B9, Canada^1

Biomedical Engineering Program, University of Western Ontario, London

ON

N6A 5B9, Canada^2

关键词: 3d dosimeters;    Absorbance spectrum;    Cancer radiotherapies;    Dose response;    Methylthymol blues;    Structural analogue;    Threedimensional (3-d);    Xylenol Orange;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/573/1/012030/pdf
DOI  :  10.1088/1742-6596/573/1/012030

来源: IOP

【 摘 要 】

The initial trial of methylthymol blue (MTB) as a chelator for ferric iron in Fricke gel dosimeters, used for three-dimensional (3D) dosimetry in cancer radiotherapy, is reported. MTB is a structural analogue of the conventionally used xylenol orange (XO); however, the absorbance spectrum of the ferric-MTB complex is shifted to higher wavelengths, which should allow for lower amount of light scattering during gel scanning. In this study, two gelatin substrates, two sources of XO and one source of MTB have been compared. The MTB- containing gels exhibited similar dose response and diffusion coefficient to the XO-containing gels at their wavelengths of maximum absorption (620 and 585 nm, respectively). In addition, the MTB gels gave an excellent dose response at 633 nm, which is an important wavelength that is already used with other 3D dosimeters.