Application of optical methods for dose evaluation in normoxic polyacrylamide gels irradiated at two different geometries

作者：Adliene D^*; Jakstas K; Vaiciunaite N

来源：Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment , 2014, 741: 88-94.

DOI：10.1016/j.nima.2013.12.057

• Polymeric gels
• Gamma irradiation
• Optical methods
• Gel dosimetry
• Interstitial brachytherapy

Normoxic gels are frequently used in clinical praxis for dose assessment or 3-D dose imaging in radiotherapy due to their relative simple manufacturing process under normal atmospheric conditions, spatial stability and well expressed modification feature of physical properties which is related to radiation induced polymerization of gels. In this work we have investigated radiation induced modification of the optical properties of home prepared normoxic polyacrylamide gels (nPAG) in relation to polymerization processes that occur in irradiated gels. Two irradiation geometries were used for irradiation of gel samples: broad beam irradiation geometry of teletherapy unit ROKUS-M with a 60Co source and point source irradiation geometry using 192Ir source of high dose rate afterloading brachytherapy unit MicroSelectron v2 which was inserted into gel via 6 Fr (2 mm thick) catheter. Verification of optical methods: UV-VIS spectrometry, spectrophotometry, Raman spectroscopy for dose assessment in irradiated gels has been performed. Aspects of their application for close evaluation in gels irradiated using different geometries are discussed. Simple pixel-close based photometry method also has been proposed and evaluated as a potential method for dose evaluation in catheter based interstitial high dose rate brachytherapy.

• 出版日期2014-3-21