Wright K, et al. – Clinicians carried out a retrospective analysis to assess the quality and consistency of volumetric–modulated arc therapy (VMAT) prostate planning at a single institution to quantify objective measures for plan quality and establish clear guidelines for plan evaluation and quality assurance. It was considered that anatomic geometry and overlap of structures has a measurable effect on the plan quality achieved for prostate patients being treated with volumetric–modulated arc therapy. By assessing multiple planning variables, they have been able to determineimportant factors affecting plan quality and establish predictive models for quality metrics that have been incorporated into the new protocol and will be tested and refined in future studies.