Investigating the relation between 3D-dose-based radiomics features and the complexity of radiotherapy treatment plans.

A key element in intensity-modulated radiotherapy is the multi-leaf collimator (MLC) which acts on the beam fluence to improve tumor dose conformity while sparing surrounding organs at risk (OARs). However, the use of the MLC may increase plan complexity, affecting the distribution of the delivered dose, and the overall clinical quality and deliverability of the treatment. Different strategies can be used to control treatment plan complexity, such as limiting the maximum number of deliverable monitor units (MUs) and using the Aperture Shape Controller (ASC). Thirty VMAT patients with two clinically acceptable treatment plans at "low" and "high" complexity were considered with the aim of comparing the corresponding calculated 3D dose. To this purpose, more than 150 textural and intensity-based features were extracted from the dose distributions (dosiomics) and statistically compared between the two groups using the Wilcoxon signed rank test. For both the tumor and the OARs, no statistically significant differences were observed in the computed features, suggesting that complexity does not affect the textural and intensity properties of the calculated dose distribution.