Uncertainty estimation for dosimetry in radiation oncology

Accurate dosimetry in radiation oncology is one of the main pillars of a successful cancer treatment. An integral part of dose measurements and calculations is the thorough and adequate assessment of the involved uncertainties. Unfortunately, this step is often neglected or done in a way which makes it challenging for others to understand the quality of presented results. In this review we summarize the concepts on the expression of uncertainties and apply these to practical examples in the context of radiation oncology. Basic concepts such as Type A and Type B uncertainties, their assessment and potential correlations as well as more advanced concepts such as effective degrees of freedom are introduced. Finally, this review gives suggestions on how the results can be presented, how the resulting uncertainty budget can be used to identify the main contributors and how the combined uncertainty can be used to establish tolerance and action limits for quality assurance processes.