The prognostic value of [18F]FDG PET/CT texture analysis prior to transplantation for unresectable colorectal liver metastases.

Introduction: To determine whether heterogeneity in colorectal liver metastases (CRLM) ¹⁸F fluorodeoxyglucose [¹⁸F]FDG distribution is predictive of disease-free survival (DFS) and overall survival (OS) following liver transplantation (LT) for unresectable CRLM.

Methods: The preoperative [¹⁸F]FDG positron emission tomography/computed tomography examinations of all patients in the secondary cancer 1 and 2 studies were retrospectively assessed. Maximum standardized uptake value (SUV_max), metabolic tumour volume (MTV), and six texture heterogeneity parameters (joint entropy_GLCM, dissimilarity_GLCM, grey level variance_SZM, size zone variance_SZM, and zone percentage_SZM, and morphological feature convex deficiency) were obtained. DFS and OS for patients over and under the median value for each of these parameters were compared by using the Kaplan Meier method and log rank test.

Results: Twenty-eight out of 40 patients who underwent LT for unresectable CRLM had liver metastases with uptake above liver background and were eligible for inclusion. Low MTV (p < 0.001) and dissimilarity_GLCM (p = 0.016) were correlated to longer DFS. Low MTV (p < 0.001) and low values of the texture parameters dissimilarity_GLCM (p = 0.038), joint entropy_GLCM (p = 0.015) and zone percentage_SZM (p = 0.037) were significantly correlated to longer OS. SUV_max was not correlated to DFS and OS.

Conclusion: Although some texture parameters were able to significantly predict DFS and OS, MTV seems to be superior to predict both DFS and OS following LT for unresectable CRLM.