Max J. Lahaye

Objectives: Diagnostic imaging of peritoneal metastases in ovarian and colorectal cancer remains pivotal in selecting the most appropriate treatment and balancing clinical benefit with treatment-related morbidity and mortality. To address the challenges related to diagnostic imaging and detecting and reporting peritoneal metastatic spread, a joint guideline was created by the European Society of Gastrointestinal and Abdominal Radiology (ESGAR), European Society of Urogenital Radiology (ESUR), Peritoneal Surface Oncology Group International (PSOGI), and European Association of Nuclear Medicine (EANM). Methods: A targeted literature search was performed and consensus recommendations were proposed using Delphi questionnaires and a five-point Likert scale. Results: A total of three Delphi rounds were performed. Consensus was reached on the position of diagnostic imaging for assessment of operability, treatment response monitoring, and follow-up of peritoneal metastases, optimal imaging modality and their technical imaging requirements depending on the indication and how to optimise communication of imaging results by the report and multidisciplinary board discussion. The complete list of recommendations is provided. Conclusion: These expert consensus statements aim to guide appropriate indications, acquisition, interpretation, and reporting of imaging for operability assessment, treatment response monitoring, and follow-up of peritoneal metastases in ovarian and colorectal cancer patients. Key Points: Question Staging peritoneal metastases (PM) helps to guide clinical decision-making for colorectal and ovarian cancer patients. How can we optimise the use of imaging techniques to assess PM? Findings Imaging plays a crucial role in the detection, operability assessment, treatment response monitoring, and follow-up of peritoneal metastases in colorectal and ovarian cancer patients. Clinical relevance These expert consensus statements aim to guide appropriate indication, acquisition, interpretation, and reporting of imaging for operability assessment, treatment response monitoring, and follow-up of peritoneal metastases in ovarian and colorectal cancer patients.