ESTRO meets Asia 2024 Congress Report

Rhonda Brown, Ivan Williams

Following the lead of the United Nations and World Health Organization, the Australian government supports the concept of equality in healthcare through its aim to deliver safe, high-quality care in the right place at the right time.

Dosimetric audits drive equality Dosimetric audits are an important tool to ensure consistency of radiation oncology practice and equivalency in multi-institutional clinical trials, validation of new technologies and techniques, the understanding of limitations of planning and treatment systems, and that risks of gross dosimetric errors are mitigated. All of these uses of audits contribute to the safety of people who receive radiation oncology treatment.

Equality by design The Australian Clinical Dosimetry Service (ACDS) was designed through collaboration between government bodies, the radiotherapy professions and patient advocates to achieve the goal of equity of quality and risk mitigation for all radiotherapy patients across Australia and New Zealand (ANZ). Therefore, access to the audit service, the quality of the audit service, and the cost to the radiotherapy provider must be independent of geography.

Equality via independence The ACDS is separate from any commercial enterprise or radiotherapy provider. Its governance structure involves the Australian government's ethical, legal and financial oversight and an independent committee of experts for clinical and technical oversight. The aggregated data from multiple independent measurements across multiple planning and treatment platforms is a source of “ground truth” for evidence-based decision-making. The ACDS participates in regular benchmarking activities against international peer auditing bodies and performs ongoing research and development with a strong peer-reviewed publication record.

Building the audit service Building on existing international audit approaches, a three-level audit structure was developed by the ACDS. The audit progressively increases in complexity and thus allows for troubleshooting [A1] suboptimal results from a high-level audit through the use of a lower-level one. A major challenge is the logistics of reliably delivering multiple overlapping onsite and remote audits with a uniform standard of quality and cost, to a population separated by desert, ocean and international borders. A new audit modality requires three to four years to enable the development from initial research, design, field trials and evaluation to the delivery of a mature audit. The data collected undergoes cyclical quality-control review, which informs refinement of processes. Over more than a decade, the ACDS has developed from testing conformal treatments on conventional linacs to include the modern techniques and speciality treatment machines that are used in ANZ.

Fundamental to the development of the audit programme is oversight by independent clinical experts, who are provided by the national professional bodies and clinical trials group. They ensure that the audit methods are appropriate and that the clinical impact of scoring metrics and sub-optimal outcomes are understood.

What is the impact?

Dosimetry audit and audit programme development is a specialist field that requires approximately five to 10 years of experience and data across a large cohort of institutions and technologies to develop the tools and expertise to identify and advise on poor audit performance. After 13 years, the ACDS has aggregated over 30,000 data points, which have been obtained from more than 1200 audits across ANZ.

ACDS thoroughly investigates any out-of-tolerance audit outcomes and can demonstrate that patient safety and risk mitigation have been increased as systemic errors in radiotherapy systems have been identified and corrected. Common features in sub-optimal audit performance relate to beam modelling, planning techniques, image guidance and dose calculation algorithm limitations