| Paper | Title | Page |
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| WEPSH007 | Radiochromic Film as a Dosimetric Tool for Low Energy Proton Beams | 397 |
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Funding: King Abdulaziz City for Science and Technology (KACST), Grant No 11-BIO1428-20 EBT3 and HDV2 GAFCHROMICTM films were tested for dose measurements at a 26.5 MeV and 6 mm Bragg peak proton beam. Beam output was calibrated using IAEA TRS-398 reference dosimetry protocol with calibrated chamber in water. Films were calibrated in terms of dose to water by exposing calibration film pieces within a solid water phantom at depth of 3 mm. EBT3 films were irradiated to doses of up to 10 Gy with both 4 MV photon and 26.5 MeV proton beams, while pieces of the HDV2 radiochromic films were irradiated to doses of up to 128 Gy proton beam. Irradiated pieces of the EBT3 films were tested for activation using Germanium detector. Their energy spectra were measured over a period of 40 minutes. EBT3 film model response was 3 times higher for protons than photons. When irradiated in proton beam the EBT3 was 24 times more sensitive than HDV2 films. For the EBT3 film model, few proton-activated processes were identified resulting in short-lived radioisotopes. EBT3 film can be used for measurements for doses of up to 10 Gy using a green color channel of the scanned images, while the red color channel of the HDV2 scanned film images can be used for measurements of much higher doses. |
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| WEPSH008 | Characterization of the CS30 Cyclotron at KFSH&RC for Radiotherapy Applications | 400 |
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Funding: King Abdulaziz City for Science and Technology (KACST), Grant No 11-BIO1428-20 The 26.5 MeV beam of the CS30 Cyclotron at King Faisal Specialist Hospital and Research Centre (KFSH&RC) was characterized dosimetrically for the use in radiobiological experiments for pre-clinical and radiotherapy studies. Position of the beam’s Bragg peak was measured with a stack of 60 pieces of HDV2 model GAFCHROMICTM films (105 microns thick each). This film type was specifically designed for measurement of very high doses, ranging up to 1,000 Gy. Output of the proton beam was calibrated using IAEA TRS-398 reference dosimetry protocol with calibrated parallel plate chamber in water. The response of the film was calibrated in terms of dose to water by exposing calibration film pieces within a solid water phantom. The position of the Bragg peak was found to be at around 6 mm when 10 to 20 nA proton beam current was used. Pieces of radiochromic film were irradiated at 40, 70 and 100 cm from the primary collimator, where the Gaussian shaped beam profiles had values of 12, 26, 45 mm FWHM respectively. Proton beam characteristics in terms of the output and beam size appear to be acceptable for pre-clinical studies. |
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