Impact of complexity and computer control on errors in radiation therapy

A number of recent publications in both the lay and scientific press have described major errors in patient radiation treatments, and this publicity has galvanised much work to address and mitigate potential safety issues throughout the radiation therapy planning and delivery process. The complexity of modern radiotherapy techniques and equipment, including computer-controlled treatment machines and treatment management systems, as well as sophisticated treatment techniques that involve intensity-modulated radiation therapy, image-guided radiation therapy, stereotactic body radiation therapy, volumetric modulated arc therapy, respiratory gating, and others, leads to concern about safety issues related to that complexity. This article illustrates the relationship between complexity and computer control, and various safety problems and errors that have been reported, and describes studies that address the issue of these modern techniques and whether their complexity does, in fact, result in more errors or safety-related problems. Clinical implications of these results are discussed, as are some of the ways in which the field should respond to the ongoing concerns about errors and complexity in radiation therapy.