A Computed Tomography-Based Score to Predict Survival in Patients With Adrenocortical Carcinoma: A Proof-of-Concept Study

Purpose: Adrenocortical carcinoma (ACC) is a rare condition with a poor and hardly predictable prognosis. This study aims to build and evaluate a preoperative computed tomography (CT)-based score (CT score) using features previously reported as biomarkers in ACC to predict overall survival (OS) in patients with ACC. Methods: A CT score based on preoperative CT examinations combining shape elongation, maximum tumour diameter, and the European Network for the Study of Adrenal Tumors (ENSAT) stage was built using a logistic regression model to predict OS duration in a development cohort of 89 patients with ACC. An optimal cut-off of the CT score was defined and the Kaplan-Meier method was used to assess OS. The CT score was then tested in an external validation cohort of 54 patients wit ACC. The C-index of the CT score for predicting OS was compared to that of ENSAT stage alone. Results: The CT score helped discriminate between patients with poor prognosis and patients with good prognosis in both the validation cohort (54 patients; mean OS, 69.4 months; 95% confidence interval [CI]: 57.4-81.4 months vs mean OS, 75.6 months; 95% CI: 62.9-88.4 months, respectively; P = .022). In the validation cohort the C-index of the CT score was significantly better than that of the ENSAT stage alone (0.62 vs 0.35; P = .002). Conclusion: A CT score combining morphological criteria, radiomics, and ENSAT stage on preoperative CT examinations allows a better prognostic stratification of patients with ACC compared to ENSAT stage alone.