Subcutaneous Adipose Tissue Attenuation Change on Chest CT Is Associated with Overall Survival After Allogeneic Hematopoietic Stem Cell Transplantation.

OBJECTIVE: Early chest computed tomography (CT) examinations are frequently performed after allogeneic hematopoietic stem cell transplantation (allo-HSCT) due to respiratory symptoms or clinical deterioration. Subcutaneous adipose tissue attenuation (SATA) has recently been proposed as a quantitative imaging marker of systemic tissue alterations related to fluid redistribution and inflammatory processes. This study aimed to evaluate interval changes in SATA after allo-HSCT and to investigate their association with overall survival. MATERIAL AND METHODS: In this retrospective single-center study, adult allo-HSCT recipients who underwent non-contrast chest CT both before transplantation and within 30 days after transplantation were included. SATA was measured in Hounsfield units (HU) using standardized circular regions of interest placed in the anterior chest wall. The interval change in attenuation Hounsfield units (ΔHU) was calculated as post-transplant minus pre-transplant values. Cox proportional hazards regression was used to assess the association between ΔHU and survival. Kaplan-Meier analysis was performed after dichotomization according to the median ΔHU value. RESULTS: A total of 104 patients were included. SATA increased on early post-transplant CT compared with baseline (P < 0.001). Higher ΔHU values were associated with worse overall survival (hazard ratio per 5-HU increase: 1.18; 95% confidence interval: 1.03-1.35; P = 0.016). Patients with ΔHU above the median (16-HU) demonstrated significantly poorer survival compared with those below the median (log-rank P = 0.0003). CONCLUSION: SATA increases after allo-HSCT, and greater interval increases are associated with worse survival outcomes. Quantitative assessment of SATA may provide a simple, non-invasive imaging biomarker for early risk stratification in allo-HSCT recipients.