We analysed quantitative biomarkers derived from both baseline whole-body imaging and blood serum to identify prognostic markers in patients treated within the lutetium-177 prostate-specific membrane antigen (LuPSMA) phase 2 trial.
PET image analysis was carried out using whole-body segmentation quantifying molecular tumour volume (SUV > 3 threshold for PSMA, SUV > liver+2sd for fluorodeoxyglucose (FDG) including SUVmax and SUVmean. For baseline bone scans, EXINI bone scan index (BSI) was used to calculate the percentage of involved bone. Baseline alkaline phosphatase (ALP), lactate dehydrogenase (LDH), prostate specific antigen (PSA) and PSA doubling time were also used in this analysis. We used univariate cox regression analysis and log-rank comparison with optimised cut-offs to find suitable biomarkers prognostic of overall survival from time of enrolment.
This analysis identified FDG-positive tumour volume (FDGvol; HR 2.6; 95% CI, 1.4-4.8), mean intensity of PSMA-avid tumour uptake (PSMAmean; HR 0.89; 95% CI, 0.8-0.98), bone scan index (BSI; HR 2.3; 95% CI, 1.2-4.4), ALP (HR 1.1; 95% CI, 1-1.2) and LDH (HR 1.2; 95% CI, 1-1.5) as biomarkers prognostic of overall survival.
In addition to established biomarkers, both FDG and PSMA PET/CT parameters have prognostic significance for survival in men undergoing LuPSMA therapy.
European journal of nuclear medicine and molecular imaging. 2020 Mar 05 [Epub ahead of print]
Justin Ferdinandus, John Violet, Shahneen Sandhu, Rodney J Hicks, Aravind S Ravi Kumar, Amir Iravani, Grace Kong, Tim Akhurst, Sue Ping Thang, Declan G Murphy, Scott Williams, Michael S Hofman
Department of Nuclear Medicine, University Hospital Essen, Essen, Germany., Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia., Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia., Molecular Imaging and Therapeutic Nuclear Medicine, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia., Sir Peter MacCallum Department of Oncology, Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne, VIC, Australia., Molecular Imaging and Therapeutic Nuclear Medicine, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia. .