Radiomics workflow definition & challenges - German priority program 2177 consensus statement on clinically applied radiomics
Authors: Floca Ralf , Bohn Jonas , Haux Christian , Wiestler Benedikt , Zöllner Frank G. , Reinke Annika , Weiß Jakob , Nolden Marco , Albert Steffen , Persigehl Thorsten , Norajitra Tobias , Baeßler Bettina , Dewey Marc , Braren Rickmer , Büchert Martin , Fallenberg Eva Maria , Galldiks Norbert , Gerken Annika , Götz Michael , Hahn Horst K. , Haubold Johannes , Haueise Tobias , Große Hokamp Nils , Ingrisch Michael , Iuga Andra-Iza , Janoschke Marco , Jung Matthias , Kiefer Lena Sophie , Lohmann Philipp , Machann Jürgen , Moltz Jan Hendrik , Nattenmüller Johanna , Nonnenmacher Tobias , Oerther Benedict , Othman Ahmed E. , Peisen Felix , Schick Fritz , Umutlu Lale , Wichtmann Barbara D. , Zhao Wenzhao , Caspers Svenja , Schlemmer Heinz-Peter , Schlett Christopher L. , Maier-Hein Klaus , Bamberg Fabian 
Published: June 2024

Abstract
Objectives
Achieving a consensus on a definition for different aspects of radiomics workflows to support their translation into clinical usage. Furthermore, to assess the perspective of experts on important challenges for a successful clinical workflow implementation.

Materials and methods
The consensus was achieved by a multi-stage process. Stage 1 comprised a definition screening, a retrospective analysis with semantic mapping of terms found in 22 workflow definitions, and the compilation of an initial baseline definition. Stages 2 and 3 consisted of a Delphi process with over 45 experts hailing from sites participating in the German Research Foundation (DFG) Priority Program 2177. Stage 2 aimed to achieve a broad consensus for a definition proposal, while stage 3 identified the importance of translational challenges.

Results
Workflow definitions from 22 publications (published 2012–2020) were analyzed. Sixty-nine definition terms were extracted, mapped, and semantic ambiguities (e.g., homonymous and synonymous terms) were identified and resolved. The consensus definition was developed via a Delphi process. The final definition comprising seven phases and 37 aspects reached a high overall consensus (> 89% of experts “agree” or “strongly agree”). Two aspects reached no strong consensus. In addition, the Delphi process identified and characterized from the participating experts’ perspective the ten most important challenges in radiomics workflows.

Conclusion
To overcome semantic inconsistencies between existing definitions and offer a well-defined, broad, referenceable terminology, a consensus workflow definition for radiomics-based setups and a terms mapping to existing literature was compiled. Moreover, the most relevant challenges towards clinical application were characterized.

Critical relevance statement
Lack of standardization represents one major obstacle to successful clinical translation of radiomics. Here, we report a consensus workflow definition on different aspects of radiomics studies and highlight important challenges to advance the clinical adoption of radiomics.

Key Points

Published radiomics workflow terminologies are inconsistent, hindering standardization and translation.

A consensus radiomics workflow definition proposal with high agreement was developed.

Publicly available result resources for further exploitation by the scientific community.

Graphical Abstract