Figure 1 Key elements of the proposed modified Delphi study Figure 1 | Key elements of the proposed modified Delphi study. The Delphi method is a widely accepted technique of structured and systematic information gathering from a group of experts (termed the Delphi Panel) on a specific topic using a series of questionnaires. The Delphi method enables a panel of experts to provide insights and opinions, even when they are not located in the same geographic area. The current study uses a modified Delphi method, in which an iterative sequence of online surveys were combined with a physical meeting of the panel of experts Bruinsma, S. M. et al. (2017) Semantics in active surveillance for men with localized prostate cancer — results of a modified Delphi consensus procedure Nat. Rev. Urol. doi:10.1038/nrurol.2017.26