Tools to assess the complexity of radiotherapy plans.

In radiotherapy treatments, intensity-modulated techniques like VMAT and Tomotherapy are extensively used to guarantee both target coverage and organs at risk sparing at the same time. However, the bottleneck of using modulated fields is to limit the so-called complexity of the treatments in a way that it does not impact their final clinical quality and deliverability. In this contribution, we provide an overview of the latest results obtained at our institution concerning the benchmark of planning strategies that limit the complexity of intensity-modulated treatments without affecting the clinical quality of the plans. Furthermore, we will present two newly developed software libraries (TCoMX and VCoMX) that extract a number of so-called complexity metrics from the plans, namely indicators that quantify several possible sources of complexity. A description of how these indicators are related to the different planning strategies adopted and to the corresponding dosimetric and clinical outcomes will be provided. Finally, results about their potential application to improve the radiotherapy workflow in the future will be presented.