https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:42635 3 ionisation chamber following the International Electrotechnical Commission standard. Film was also used to illustrate leakage distribution in the patient plane. Angular and energy dependences of the leakage radiation were quantified as well as a two-dimensional leakage profile in the plane parallel to one applicator. Results: Leakage was found when the diameter of primary collimator of the kV tube exceeded the external dimension of the applicator wall. In the patient plane all applicators showed similar leakage rates with the leakage distribution dependent upon applicator design. Mean patient plane leakage was 1.37% of central axis air kerma rate, exceeding the 0.5% limit specified in the standard. Leakage was shown to be profoundly energy dependent with maximum leakage of 11.8% for the 200 kV beam, 1.3% for 150 kV and 0.2% for 100 kV. Angular dependence measurements showed a 10.3% change in leakage between the minimum and maximum positions. Conclusion: The combination of shielding thickness, primary collimator design and applicator dimensions permits unwanted radiation to contribute dose outside the treatment field when energies ≥150 kV are used. Advanced in Knowledge: Even carefully designed modern kv therapy systems can exhibit leakage in some areas. Thorough assessment of leakage is needed prior to release for clinical use.]]> Wed 31 Aug 2022 09:25:30 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:1627 Wed 24 Jul 2013 22:55:05 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:18869 Wed 11 Apr 2018 09:20:07 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37462 Wed 02 Mar 2022 14:28:00 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:547 Thu 25 Jul 2013 09:10:25 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33046 Thu 03 Feb 2022 12:19:33 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:1888 Sat 24 Mar 2018 08:31:19 AEDT ]]>