Delphi consensus of specialist radiologists on imaging criteria for gadolinium contrast use and whole-body MRI in prostate cancer.

objectiveTo achieve expert consensus on structured prostate MRI criteria for gadolinium-based contrast agent (GBCA) administration and whole-body MRI (WB-MRI) escalation in the diagnostic evaluation and staging of prostate cancer (PCa). MATERIALS AND

methodsA three-round modified online Delphi survey was conducted among UK specialist prostate radiologists. Participants rated predefined clinical and MRI criteria using structured Likert agreement scales and provided free-text comments to refine decision-making. Quantitative responses were summarised descriptively. Qualitative thematic analysis informed subsequent rounds. Consensus for each decision criterion was predefined as ≥ 70% agreement. The study was conducted in accordance with CREDES (Conducting and Reporting of Delphi Studies) guidance.

resultsThe number of radiologists who completed Rounds 1, 2, and 3 was 21, 14, and 11, respectively. Two principal outputs were defined: (1) consensus criteria for GBCA administration; (2) consensus criteria for WB-MRI escalation. For GBCA administration, consensus supported its use for Prostate Imaging-Reporting and Data System (PI-RADS) 3 lesions (86%) and low prostate imaging quality (PI-QUAL ≤ 3; 91%), and avoidance in high-quality (PI-QUAL 4-5) images (73%). Fixed prostate-specific antigen (PSA) or PSA density thresholds did not reach consensus when considered in isolation. For WB-MRI, consensus supported escalation for T3a/T3b disease (93%), combined clinical and radiological suspicion of metastasis (91%), and high-risk profiles (PSA ≥ 20 ng/mL, Gleason ≥ 8 or ≥ T3; 86%).

conclusionThis Delphi study established expert consensus on structured MRI criteria to guide selective GBCA administration and WB‑MRI escalation, with the potential to reduce unnecessary GBCA administration, improve consistency and optimise prostate MRI workflow. KEY POINTS: Question What consensus-based criteria can guide on-table gadolinium-based contrast agent administration and whole-body MRI escalation during prostate MRI to reduce variability and unnecessary imaging? Findings Delphi consensus established imaging-based criteria integrating lesion suspicion, image quality and high-risk features to guide selective gadolinium-based contrast agent administration and whole-body MRI escalation. Critical relevance statement This article critically evaluates gadolinium-based contrast agent administration in prostate MRI and defines consensus-based standardised decision-making criteria. These criteria aim to reduce unnecessary gadolinium-based contrast agent administration and improve efficiency and consistency in staging pathways.