Prognostic role of pretreatment [¹⁸F]FDG PET/CT in patients affected by adrenocortical carcinoma and treated with chemotherapy.

Abstract

PURPOSE: [18F]-fluorodesoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) is used for diagnosis and staging of adrenocortical cancer (ACC), its prognostic role needs to be explored. This study aimed to investigate the prognostic role of pre-EDP-M [18F]FDG PET/CT parameters in ACC patients treated with first line chemotherapy (ChT) in term of progression free survival (PFS) and overall survival (OS). METHOD: this retrospective, monocentric study included metastatic ACC patients treated with EDP-M after [18F]FDG PET/CT staging. Clinico-pathological features and PET/CT semiquantitative parameters such as standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), SUVmax/liver ratio (SL) and SUVmax/blood-pool ratio (SBP) were collected. RESULTS: forty-one ACC patients were included. Median PFS was 9.3 months and median OS was 14.3 months. PET/CT parameters did not correlate with the response to ChT, while they were affordable prognosticators. Lower MTV (HR 0.36, CI: 0.17–0.74; p < 0.01), lower TLG (HR 0.31, CI: 0.15–0.64; p < 0.01), lower tumour burden (HR 0.45, CI: 0.23–0.94; p = 0.03), attained the statistical significance in univariable analysis in terms of longer PFS, lower TLG (HR 0.33, CI: 0.15–0.71; p < 0.01) confirmed its independent role in multivariable analysis. At univariable analysis lower MTV (HR 0.36, CI: 0.16–0.82; p = 0.01) correlated with longer OS. Lower TLG confirmed its role in the multivariate analysis (HR 0.28, CI 0.11–0.69; p < 0.01). CONCLUSION: pretreatment TLG was reported as independent prognostic tools for ACC patients treated with EDP-M. No correlations between PET/CT parameters and response to ChT were reported.