The link between protocol deviations in radiotherapy and worse clinical outcomes, is well documented in several clinical trials [1]. In real-world clinical practice, one of the key strategies employed by centres to prevent errors is peer review. Following the development of a radiation therapy treatment plan, an evaluation is performed by the treating radiation oncologist and typically a medical physicist, that may involve multiple iterations to achieve an acceptable plan. Peer review is another key component of plan evaluation that involves the appraisal by additional radiation oncologists, and potentially other members of the multidisciplinary team.