The Australian Clinical Dosimetry Service (ACDS) is an independent radiotherapy dosimetry auditing program, providing quality assurance for radiation oncology facilities across Australia and New Zealand. Recognising the rapid development of Australian clinical practice, the ACDS began development of an end-to-end stereotactic ablative radiotherapy (SABR) dosimetry audit in 2018.
SABR is a relatively new technique used to deliver highly-focused and comparatively large doses of radiation to very small areas of the body. SABR is a very precise treatment which makes it suited to treating small tumours such as those in lung, spine, liver and lymph nodes. In SABR treatment, the highly-focused doses make it particularly important to verify that the dose delivered to the patient is correct, and that the dose was delivered accurately to the location of the tumour.
ARPANSA’s ACDS staff specifically designed a humanoid phantom (manikin) to simulate a patient’s treatment and enable the ACDS to measure SABR dose. The phantom includes special plastics which realistically simulate human lung, spine and soft tissue tumours. During the ACDS audits, the radiotherapy facility plan the SABR treatment as they would for a real patient. ACDS staff attend on-site and measure the dose delivered to the phantom to confirm that the planned dose delivered by the facility is the dose received by the phantom.
In 2018, the ACDS performed SABR dosimetry trial audits in 21 radiotherapy facilities across Australia. The audit was performed for a range of lung, spine and soft tissue SABR treatments, with results reported to the facilities. Performance of the SABR dosimetry audit provides assurance to radiotherapy facilities, giving them confidence in the accurate delivery of radiation dose to their patients. The ACDS SABR audit is also used in clinical trial quality assurance, which is important for improving the way SABR treatments are delivered to patients.
Development and delivery of the SABR audit program is making a vital contribution to the safety of advanced radiotherapy techniques and improvement of outcomes for cancer patients around Australia. This innovation also cements ARPANSA’s position in the international forefront of radiation therapy dosimetry.