Background
Radiation therapy cures cancer and improves the quality of life for cancer survivors. Modern radiotherapy treats highly targeted, high-dose-low-fractionation courses using sophisticated technology and delivery techniques (VMAT, SABR, SRS). The potential for errors in radiotherapy is high, as it involves a complex patient pathway with many potential failure points. The Australian Clinical Dosimetry Service provides independent, standardised, dosimetric measurements, accumulating data and expertise to assist radiotherapy facilities to improve accuracy of dose delivery to their patients. The specific audit program was designed to ensure sufficient sensitivity for the strict requirements of clinical trial participation.
Aims
The paper presents case studies and trends against accumulated data from the ACDS audit program and the results of follow up investigations.
Methods
The ACDS audits a comprehensive suite of modern radiotherapy techniques and treatment platforms in Australia and New Zealand with a periodic, multi-level audit structure. The ANZ Dataset is the ACDS’ comprehensive database of radiotherapy equipment and beam models, providing an independent method to identify trends and outliers when assessing audit outcomes.
Results
Since 2011, the ACDS has performed over 1,200 dosimetry audits, around 9% of which produced an Out of Tolerance outcome. The ACDS has identified issues of varying significance in every node of the patient pathway. Common OT errors occurred through IGRT errors, usually limited to single-fraction instances, or planning and beam modelling errors which can be observed across multiple, linked sites.
Conclusions
Regular participation in high-quality dosimetric audits ensures confidence that radiation dose is accurately delivered in a radiotherapy facility. ACDS audits are sensitive to errors and can diagnose root causes throughout the treatment pathway. Reviews of suboptimal audit results have resulted in changes to clinical practice which have reduced actual or potential clinical hazards, contributing to the safety and quality of patient outcomes throughout Australia and New Zealand.