Therefore, it is recommended to use a dosimeter that has these restrictions and to measure the dose levels more accurately in the 3 dimensions to be used in the areas.1įor the dosimetry methods based on gel, magnetic resonance imaging (MRI) was used to read the dose. For example, the dimensions of the ionization chamber in high-dose or low-resolution thermoluminescent dosimetry may not be suitable for 3-dimensional (3D) dosimetry. Polymer gel, MAGIC-f, radiation dosimetry, velocity, attenuation coefficientĪ conventional dosimeter is used to measure the dose at a point or in a plane, which may have some limitations. Maximum sensitivity time and temperature readings of the MAGIC-f ultrasonic parameters were concluded 24 hours after irradiation and at a temperature of 25☌.
The ultrasonic parameters at 5☌, I5☌, and 25☌ on the gel dosimeter after 0 to 60 Gy irradiation showed that readings at 25☌ have higher sensitivity compared to 15☌ and 5☌. The sensitivity of the dose-velocity and dose-attenuation coefficient curves was observed as 50 m/s/Gy and 0.06 dB/MHz/Gy over the linear range of 4 to 44 Gy, respectively. Based on a 4-order polynomial curve, fitted on the dose-response parameters of ultrasound velocity and attenuation coefficient and observed at 24 hours after irradiation, ultrasonic parameters had more sensitivity. According to the dose-response curve, the ability of ultrasonic parameters was evaluated in dose rate readings. After calibration of the ultrasonic systems with a frequency of 500 kHz, the parameters of ultrasound velocity and attenuation coefficient of the irradiated gel samples were measured. The MAGIC-f polymer gel was irradiated under 1.25 MeV cobalt-60, ranging from 0 to 60 Gy in 2-Gy steps, and received dose uniformity and accuracy of +2%. In this study, using methacrylic and ascorbic acid in gelatin initiated by copper (MAGIC-f) polymer gel after megavoltage energy exposure, the sensitivity of the ultrasound velocity and attenuation coefficient dose-dependent parameters was evaluated.
Hossein Masoumi1, Manijhe Mokhtari-Dizaji1, Azim Arbabi2, and Mohsen Bakhshandeh3 Determine the Dose Distribution Using Ultrasound Parameters in MAGIC-f Polymer Gels