Skeletal muscle radiodensity as an automated survival predictor in men with metastatic castration-resistant prostate cancer undergoing PSMA-targeted radioligand therapy.
Authors
Affiliations (7)
Affiliations (7)
- Department of Nuclear Medicine, University Hospital Bonn, Venusberg Campus 1, 53127, Bonn, Germany.
- Department of Urology and Pediatric Urology, University Hospital Bonn, Bonn, Germany.
- Department of Diagnostic and Interventional Radiology, University Hospital Bonn, Bonn, Germany.
- Department of Nuclear Medicine, Institute of Radiology, Neuroradiology and Nuclear Medicine, Knappschaft Kliniken, University Hospital Bochum, Bochum, Germany.
- Department of Nuclear Medicine, Knappschaft Kliniken Westfalen Dortmund, Dortmund, Germany.
- Department of Psychosomatic Medicine and Psychotherapy, University Hospital Muenster, Muenster, Germany.
- Department of Nuclear Medicine, University Hospital Bonn, Venusberg Campus 1, 53127, Bonn, Germany. [email protected].
Abstract
Skeletal muscle radiodensity (SMD) is an emerging imaging-derived marker of muscle quality. Its prognostic relevance in patients with metastatic castration-resistant prostate cancer (mCRPC) undergoing [¹⁷⁷Lu]Lu-PSMA-617 radioligand therapy has not yet been systematically evaluated. This study aims to investigate the prognostic value of SMD derived from routine pretherapeutic PET/CT imaging in a large real-world mCRPC cohort treated with [¹⁷⁷Lu]Lu-PSMA-617. In this single-center study, the largest to date cohort comprising 410 mCRPC patients was analyzed. SMD was quantified automatically from the L3-level CT component of pretherapeutic [⁶⁸Ga]Ga-PSMA-PET/CT using an AI-based segmentation tool. An optimal SMD cut-off (19.26 HU) was determined for survival stratification. Associations with overall survival (OS) were assessed using multivariable Cox regression (univariable and multivariable, adjusted for baseline PSA) and Kaplan-Meier analysis. Lower SMD was associated with reduced OS (HR 1.87, P<.001). Median OS were significantly shorter in the SMD-low group compared to the SMD-high group (7.6 months vs. 12.2 months; P<.001). This prognostic stratification was seen in both, patients with or without PSA50 or PSA90 response, respectively. SMD correlated with age, albumin, and PSA, but not with BMI. SMD assessed from routine pretherapeutic PET/CT is a non-invasive prognostic biomarker in patients undergoing PSMA-targeted radioligand therapy. Integration of host-derived imaging biomarkers such as SMD with tumor-specific parameters may improve risk stratification, prehabilitation and support future individualized treatment strategies in advanced prostate cancer.