Room: Exhibit Hall
Purpose: To study the dosimetric properties of a Sr-90 beta emitter including the dose rate, percent depth dose (PDD) in solid water and source profile.
Methods: Dose rate was estimated by exposure to EBT2 film (Ashland Advanced Materials, NJ) performed at the source window and at 2, 3, and 5 mm depths in Solid water (Gammex RMI, Nashville, TN). Twenty four hours after exposure, the films were scanned in Epson Perfection flatbed scanner at 400 dpi and saved in 48-bit color. Following EBT2 film calibration on a clinac 6MeV beam, Sr-90 dose rate, PDD, and profiles were generated using ImageJ ver. 1.49v after applying background corrections and considering film orientation. The dosimetry of the source measurements were compared against MonteCarlo simulations performed in GATE ver. 6.1.The combined spectrum of 90Sr/90Y source was evaluated in a cuboid shaped water and epoxy phantoms of 8mm (height) Ã— 8mm (width) Ã— 10mm (length) based on an energy spectrum ranging from 0 to 2.28 MeV.
Results: The measured PDDs agree with GATE simulations to within 15% at 2 mm, 20% in 3 mm, and 0.01% at 5 mm depths of Solid water. The profiles agree with simulations to within 5% at 2 mm, 14% at 3 mm, and 1% at 5 mm depths. The dose rate was measured to be 4.4 Gy/sec at the surface of source window and 0.6, 0.3, and 0.05 Gy/sec, at depths of 2 mm, 3 mm, and 5 mm in Solid water, respectively.
Conclusion: The dosimetric properties of Sr-90 source were verified against MonteCarlo simulations.
Not Applicable / None Entered.