Synthesis and Optimization of Polymer Film Detector (PVACu2O) in Radiation Therapy

Abstract

Ionizing radiation has been utilized in different medical fields such as diagnosis, treatment of diseases and scientific researches based on the induced effect that occur in different types of human cells; no doubt or debate, it could induce certain effect in many applicable medical materials and even the materials used for radiation measurement and detection. In radiation therapy, for the high secured accuracy of radiation therapy dose should not exceed ± 5% of the prescribed tumor dose. To achieve that goal, an effective tool should be used for analyzing and mapping the radiotherapy treatments for cancer patients. So polymer-gel and film dosimeters have been introduced and considered depending on physical and chemical changes that occur in the polymer after irradiation. The aim of the current study was to synthesize polyvinyl alcohol cuprous oxide composite films (PVA/Cu2O) for radiation detection depending on optical changes. The method adapted from solving of 5% PVA in hot (80 ˚C) stirred water and after cooling to ambient temperature a 0.5 gram of Cu2O dissolved and stirred for 2 hours. The films were made by casting in petri dishes contained 20 ml/each. The pealed films were enveloped after drying and receiving radiation doses of 1, 2, 4, 6 … 12 Gy. The analysis revealed a gradient change in color of films from light pink to dark brown with absorption peaks at 215 and 415 nm through entire doses which were increase as dose increment. The optical density of films increases linearly and significantly (R2 = 0.9) as the dose increases from 0.06 (arb. unit) at 1 Gy to 0.4 (a u) at 12 Gy with sensitivity at 0.06 mGy. The energy band gap of the film decreased as the radiation dose increases from 3×10-12 to 2×10-12 eV. Conclusively; the feasibility of utilizing PVA/Cu2O composite films as radiation detector and personal dosimeter would be applicable in rural sectors and low economic countries.