Joint Radiomics Analysis on 18F-FDG-PET-MRI of Primary Tumor to Predict the Risk of Synchronous Distant Metastasis in Pancreatic Ductal Adenocarcinoma

Abstract PurposeThis study explores the potential of joint radiomics analysis of PET-MRI of primary pancreatic ductal adenocarcinoma (PDAC) tumor in predicting the risk of synchronous distant metastasis (SDM).MethodsTwo cohorts of PDAC patients were collected including a development cohort (n=66) receiving separate 18F-FDG-PET/CT and multi-sequence MRI, and a external test cohort (n=25) receiving hybrid PET/MR. All of these patients were confirmed with SDM after imaging. Radiomics features of primary PDAC tumors were selected and models were built for PET, MRI, and PET-MRI from the development cohort. A radiomics nomogram was constructed by combining independent clinical indicators. The developed radiomics nomogram was independently evaluated on the test cohort. ResultsThe area under the curve (AUC) values of PET, MRI, and joint PET-MRI models were 0.89, 0.86, and 0.94 in the training set and 0.77, 0.67, and 0.77 in the test set. The radiomics nomogram combing the joint PET-MRI radiomics signature, age, and CA19-9 level had good calibration and high discrimination capacity with maximum AUC value (0.93). The decision curve analysis (DCA) confirmed the radiomics nomogram had clinical usefulness. The evaluation on the independent test cohort showed that the accuracy, sensitivity, specificityand AUC values of radiomics nomogram were 84.0%, 78.6%, 90.9% and 0.85.ConclusionThe robust and effective prediction of the risk of SDM for the preoperative PDAC patients confirmed the potential of the radiomics analysis on PET/MR. The radiomics information in primary tumor may provide complementary and alerting hints for cancer staging.