Dosimetric properties of N-isopropylacrylamide polymer gel using nonelectrophoresis grade BIS in preparation

Abstract

Introduction: Unlike availability of the different grades of N, N'-methylenebisacrylamide (BIS), electrophoresis is recommended in literature as a crosslinking agent in gel preparation. As the cost of non-electrophoresis grade BIS is much less than that of electrophoresis, the dosimetric characteristics of the of the polymer gel using non-electrophoresis BIS is evaluated in terms of photon energy and dose rate. Materials and Methods: To compare the response of this gel with the one that contains electrophoresis grade BIS, two sets of N-isopropylacrylamide (NIPAM) gel were prepared using electrophoresis and non-electrophoresis BIS and irradiated to different gamma doses. Results: It was shown that the dose-response of NIPAM gel made from non-electrophoresis grade BIS is coincident to that of electrophoresis grade BIS. The study of dose response of NIPAM with non-electrophoresis grade BIS as a function of beam energy revealed no dependence on radiation energies of 1.25 MV from ⁶⁰ Co and 6 MV and 18MV from linear accelerator. It was found that dose rate has no influence on dose response of NIPAM gel with non-electrophoresis BIS. Conclusion: Substitution non-electrophoresis grade BIS not only reduces the cost of gel preparation without any adverse effect on its dose response, but also its lower background increases the dynamic range of dose linearity.