Early Survival Prediction After Intra-arterial Therapies: a 3D Quantitative MRI Assessment of Tumour Response After TACE or Radioembolization of Colorectal Cancer Metastases to the Liver

Objectives: This study evaluated the predictive role of 1D, 2D and 3D quantitative, enhancement-based MRI regarding overall survival (OS) in patients with colorectal liver metastases (CLM) following intra-arterial therapies (IAT).

Methods: This retrospective analysis included 29 patients who underwent transarterial chemoembolization (TACE) or radioembolization and received MRI within 6 weeks after therapy. Tumour response was assessed using 1D and 2D criteria (such as European Association for the Study of the Liver guidelines [EASL] and modified Response Evaluation Criteria in Solid Tumors [mRECIST]). In addition, a segmentation-based 3D quantification of overall (volumetric [v] RECIST) and enhancing lesion volume (quantitative [q] EASL) was performed on portal venous phase MRI. Accordingly, patients were classified as responders (R) and non-responders (NR). Survival was evaluated using Kaplan-Meier analysis and compared using Cox proportional hazard ratios (HR).

Results: Only enhancement-based criteria identified patients as responders. EASL and mRECIST did not predict patient survival (P = 0.27 and P = 0.44, respectively). Using uni- and multivariate analysis, qEASL was identified as the sole predictor of patient survival (9.9 months for R, 6.9 months for NR; P = 0.038; HR 0.4).

Conclusion: The ability of qEASL to predict survival early after IAT provides evidence for potential advantages of 3D quantitative tumour analysis.

Key Points: • Volumetric assessment of colorectal liver metastases after intra-arterial therapy is feasible. • Early 3D quantitative tumour analysis after intra-arterial therapy may predict patient survival. • Volumetric tumour response assessment shows advantages over 1D and 2D techniques. • Enhancement-based MR response assessment is preferable to size-based measurements.