Abstract Background Body composition (BC) analysis is performed to quantify the relative amounts of different body tissues as a measure of physical fitness and tumor cachexia. We hypothesized that relative changes in body composition (BC) parameters, assessed by an artificial intelligence–based, PACS-integrated software, between baseline imaging before the start of radioligand therapy (RLT) and interim staging after two RLT cycles could predict overall survival (OS) in patients with metastatic castration-resistant prostate cancer. Methods We conducted a single-center, retrospective analysis of 92 patients with mCRPC undergoing 177 LuLu-PSMA RLT between September 2015 and December 2023. All patients had 68 GaGa-PSMA-11 PET/CT at baseline (≤ 6 weeks before the first RLT cycle) and at interim staging (6–8 weeks after the second RLT cycle) allowing for longitudinal BC assessment. Results During follow-up, 78 patients (85%) died. Median OS was 16.3 months. Median follow-up time in survivors was 25.6 months. The 1 year mortality rate was 32.6% (95%CI 23.0–42.2%) and the 5 year mortality rate was 92.9% (95%CI 85.8–100.0%). In multivariable regression, relative change in visceral adipose tissue (VAT) (HR: 0.26; p = 0.006), previous chemotherapy of any type (HR: 2.4; p = 0.003), the presence of liver metastases (HR: 2.4; p = 0.018) and a higher baseline De Ritis ratio (HR: 1.4; p < 0.001) remained independent predictors of OS. Patients with a higher decrease in VAT (< −20%) had a median OS of 10.2 months versus 18.5 months in patients with a lower VAT decrease or VAT increase (≥ −20%) (log-rank test: p = 0.008). In a separate Cox model, the change in VAT predicted OS ( p = 0.005) independent of the best PSA response after 1–2 RLT cycles ( p = 0.09), and there was no interaction between the two ( p = 0.09). Conclusions PACS-Integrated, AI-based BC monitoring detects relative changes in the VAT, Which was an independent predictor of shorter OS in our population of patients undergoing RLT
Ruhwedel et al. (Thu,) studied this question.