Independent Dosimetry Audits as Best Practice in Radiotherapy

Tygerberg Hospital is an AFRA Regional Designated Center for Radiation Oncology and Medical Physics. The hospital requested a full IAEA QUATRO audit, which was done in November 2018. A dosimetry audit forms part of a fully comprehensive audit. A dosimetry audit was carried out on a sample of photon and electron beams in the department. This was done using equipment that was made available for use by the National Metrology Institute of South Africa (Farmer and Markus type ionisation chambers plus electrometer). The QUATRO audit team measured the doses according to the IAEA TRS 398 protocol [2]. Apart from the beam quality correction factors, corrections were also done for temperature and pressure, polarisation and ion recombination.