Correlation between [68Ga]Ga-PSMA-11 PET/CT-derived skeletal muscle index and sarcopenia parameters in hypogonadal men undergoing androgen deprivation therapy for prostate cancer.

Background: Sarcopenia is an emerging health problem, and its detection in prostate cancer patients undergoing androgen deprivation therapy (ADT) is of rising importance. This study aims to evaluate the relationship between sarcopenia parameters such as estimated skeletal muscle index (SMI) using the gallium-68 labeled prostate-specific membrane antigen-11 positron-emission tomography/computed tomography ([68Ga] Ga-PSMA-11 PET/CT) imaging performed for oncological staging, hand grip strength (HGS) with dynamometer and Strength, Assistance in walking, Rise from a chair, Climb stairs, Falls (SARC-F) questionnaire score in prostate cancer patients, and to assess how these relationships are influenced by androgen deprivation duration.

Material and methods: 20 patients with prostate cancer without ADT and 39 men on ADT with a mean duration of 34.8 ± 21.8 months in a hypogonadal state were included. SMI using the psoas muscle area on the third lumbar vertebra (L3) level was measured on [68Ga]Ga-PSMA-11 PET/CT images, adjusted to height, HGS, and SARC-F score were also assessed.

Results: SMI and HGS demonstrated a strong positive correlation (r = 0.85, p < 0.001) among all participants. SMI and SARC-F scores showed a moderate negative link (r = -0.74, p < 0.001), while HGS and SARC-F scores were strongly negatively associated (r = -0.95, p < 0.001). In hypogonadal men, SMI and HGS were both negatively correlated with ADT duration (r = -0.57, p < 0.001; and r = -0.82, p < 0.001). A strong positive correlation was found between SARC-F score and ADT duration (r = 0.43, p < 0.001).

Conclusions: The present results confirm that prolonged ADT in prostate cancer patients is associated with a significant decline in muscle mass and strength, and support the integration of both imaging ([68Ga]Ga-PSMA-11 PET/CT-derived SMI) and simple clinical tools (HGS, SARC-F) in the routine assessment of prostate cancer patients receiving ADT.