Cancer sufferers seeking radiation treatment in Australia can be assured of world-class standards following the release of results from an international comparison of radiation measurement.
One of the procedures to treat cancer is radiotherapy, which involves projecting a beam of high intensity gamma irradiation on the affected organ or area of the body. Making sure that the beam gives the right amount of radiation is crucial - if the dose is too high, there is a risk of destroying surrounding tissue, and if it is too low, the treatment may not be effective.
The Australian Nuclear Science and Technology Organisation (ANSTO) have excelled in an international comparison organised by the International Atomic Energy Agency (IAEA) for their work in calibrating ionisation chambers in hospitals. Calibrating the ionisation chambers that measure these doses is the responsibility of staff from ANSTO's Secondary Standard Dosimetry Laboratory (SSDL).
The comparison involved the IAEA sending out thermoluminescent dosimeters to member states of the IAEA/World Health Organisation network of Secondary Standard Dosimetry Laboratories from around the world. Each SSDL irradiates he dosimeters to a specified target dose. The IAEA measures the response and reports the results.
Results show that the ANSTO measurements were closer than one per cent from the target, considered a very accurate result, and exceeding the standard of 3.5 per cent deviation considered acceptable by the IAEA.
National and international authorities recommend that each ionisation chamber is calibrated on a regular basis to meet quality assurance and quality control practices. By exposing the chamber to ANSTO's cobalt-60 source, staff from the SSDL ensure reliability of dosimetry measurements, and meet international standards set by the IAEA in Vienna.
The SSDL calibration of dosimetry equipment also provides an important traceable link between Australian users of radiotherapy and the Australian primary standard of radiation absorbed dose.