A medical linear accelerator (linac) was installed in 2009. The linac is of the type used to deliver radiotherapy and therefore allows ARPANSA to calibrate therapy dosemeters at megavoltage beam qualities close to those used by radiotherapy treatment centres.
The medical standards linac is an Elekta Synergy capable of delivering 3 photon energies (6 MV, 10 MV and 18 MV) and ten electron beams between 4 and 22 MeV. Different photon energies are available by changing filters in the head but these beams are not currently commissioned.
The linac was upgraded with a Patient Support System (patient table) in 2010 and a kilovoltage imager was added in 2012. The linac has the MLCi2 beam shaping device and a portal imager. The Record and Verify system MOSAIQ is installed and can be used to deliver radiotherapy treatment plans developed on similar linacs in local hospitals.
Transition from Elekta Synergy to VersaHD for calibrations
ARPANSA’s calibration service for linac MV photons and electrons will transition from the Synergy linac to the VersaHD in 2021. For regular photon beams there will be minor changes to the TPR20,10 of the calibration beams (6, 10, 18MV). ARPANSA has also used the primary standard for the FFF beams, with a view to extending the direct calibration service. There are still some steps to complete, including modelling of the graphite to water correction factors and method validation. Electron cross-calibrations will be done at 15 MeV instead of 18 MeV.
Research Opportunities
The medical standards accelerator is available for research use where the benefit of the research is improved medical use of radiation. Please contact the megavoltage dosimetry team to discuss your project.
For further information regarding radiotherapy services, please contact psdl@arpansa.gov.au.
