Soft tissue tumor imaging in adults: European Society of Musculoskeletal Radiology–Guidelines 2024: imaging immediately after neoadjuvant therapy in soft tissue sarcoma, soft tissue tumor surveillance, and the role of interventional radiology
Authors: Noebauer-Huhmann Iris-Melanie , Vilanova Joan C. , Papakonstantinou Olympia , Weber Marc-André , Lalam Radhesh K. , Nikodinovska Violeta Vasilevska , Sanal Hatice T. , Lecouvet Frédéric E. , Navas Ana , Martel-Villagrán José , de Rooy Jacky W. J. , Fritz Jan , Verstraete Koenraad , Grieser Thomas , Szomolanyi Pavol , Chaudhary Snehansh , Sconfienza Luca Maria , Tagliafico Alberto S. , Afonso P. Diana , Albtoush Omar M. , Aringhieri Giacomo , Arkun Remide , Aström Gunnar , Bazzocchi Alberto , Botchu Rajesh , Breitenseher Martin , Dalili Danoob , Davies Mark , de Jonge Milko C. , Mete Berna D. , Gielen Jan L. M. A. , Hide Geoff , Isaac Amanda , Ivanoski Slavcho , Mansour Ramy M. , Mccarthy Catherine , Muntaner-Gimbernat Lorenzo , O’Donnell Paul , Örgüç Şebnem , Rennie Winston J. , Resano Santiago , Robinson Philip , Ter Horst Simone A. J. , van Langevelde Kirsten , Wörtler Klaus , Koelz Marita , Panotopoulos Joannis , Windhager Reinhard , Fueger Barbara J. , Schmid Maximilian , Vanhoenacker Filip M. 
Published: December 2024

Abstract
Objectives
An update of the first European Society of Musculoskeletal Radiology (ESSR) consensus on soft tissue tumor imaging in 2015 became necessary due to technical advancements, further insights into specific entities, and the revised WHO classification (2020) and AJCC staging system (2017). The third part of the revised guidelines covers algorithms and techniques beyond initial imaging: (1) Imaging after neoadjuvant therapy in soft tissue sarcoma, (2) sarcoma surveillance, and (3) special aspects, including surveillance of non-malignant entities and the role of interventional radiology.

Materials and methods
A validated Delphi method based on peer-reviewed literature was used to derive consensus among a panel of 46 specialized musculoskeletal radiologists from 12 European countries. Statements that had undergone interdisciplinary revision were scored online by level of agreement (0 to 10) during two iterative rounds that could result in either ‘group consensus,’ ‘group agreement,’ or ‘lack of agreement.’

Results
The three sections contain 47 statements with comments. Group consensus was reached in 91.5%, group agreement in 6.4%, lack of agreement in 2.1%. In sarcoma, imaging immediately after neoadjuvant therapy is pivotal for determining the therapy effects and for resection-planning; surveillance should include imaging at fixed grade- and type-dependent intervals. In general, MRI is the method of choice for loco-regional surveillance of soft tissue sarcomas, and chest CT to assess metastatic disease. Interventional radiology has a role, especially in oligometastatic disease, palliative tumor control and local recurrences.

Conclusion
Strategies for standardized soft tissue tumor imaging regarding therapy control, surveillance, and useful interventional procedures are provided.

Key Points
QuestionAn ESSR consensus update on soft tissue tumor imaging regarding surveillance became necessary due to technical advancements, further entity-specific insights, and revised WHO- and AJCC-classifications.
FindingsImaging immediately after neoadjuvant therapy in soft tissue sarcoma is pivotal. Post-therapeutic surveillance should include imaging at regular intervals, stratified for tumor grade and type.
Clinical relevanceThe updated ESSR soft tissue tumor imaging guidelines aim to provide best practice expert consensus for standardized imaging, to support radiologists in their decision-making, and to improve examination comparability, both in individual patients and in future studies on individualized strategies.