Skin dose measurements suggest that the IEC 6 requirement of 90% for the maximum available field size may be exceeded for an open field, but this requirement is met when an electron filter is used.Ĭonclusion: Our beam physics measurements demonstrate that this unit does not differ significantly from previous Cobalt-60 units. This increased penumbra is an expected trade-off from increased patient clearance. Measured Penumbras were comparable to previous Cobalt-60 units with 45 cm source to diaphragm distance, but slightly larger than the Equinox 80 unit, which has a source to diaphragm distance of 50 cm. Beam flatness and symmetry showed little change from previous Cobalt-60 units such as THERATRON 780C and the currently available Equinox 80. Results: Percent depth doses were in good agreement with BJR supplement 25 data. PDD's were measured both with and without the electron filter, and these data were used to determine skin dose at an effective depth of 0.5 mm. Beam flatness, symmetry and penumbra were measured using IEC 976 definitions and prescribed test conditions. Results are compared to published Cobalt-60 beam characteristics such as BJR Supplement 25. Methods: Percentage depth doses and dose profiles were collected using an IBA Blue Phantom equipped with a photon diode (PDF3G). The beam characteristics of this unit is reported. The unit is only available in 80 cm source to axis (SAD) configuration. The source to diaphragm distance (SDD) is kept at 45 cm. The unit features a touch screen control console, asymmetric collimators, and built-in backup power, which allows up to 4 hours of clinical use during power outages. Purpose: Best Theratronics recently brought to market the GammaBeam 100-80, an updated manual Cobalt-60 teletherapy unit. L Xu*, A Ciresianu, W Kaszuba, Best Theratronics, Ottawa, ON Presentations MO-RPM-GePD-T-2 (Monday, July 31, 2017) 3:45 PM - 4:15 PM Room: Therapy ePoster Lounge Beam Characterization of the GammaBeam 100-80 Cobalt-60 Unit
0 kommentar(er)
