Body Composition Analysis: A Quantitative Imaging Biomarker for Perioperative Risk Stratification
Author Block: A. Channarayapatna Srinivasa1, S. S. Poluri2, Z. T. J. Sim2, E. C. Z. H. Ng2, K. Y. How2, B. K. N. Prakash1, C. H. Tan2; 1Singapore/SG, 2singapore/SG
Purpose: This study aims to examine the prognostic significance of abdominal body composition compartments—superficial subcutaneous adipose tissue (SSAT), deep subcutaneous adipose tissue (DSAT), visceral adipose tissue (VAT), and skeletal muscle—on perioperative outcomes in colorectal cancer surgery, and to assess the additional value of cross-sectional area (CSA) and attenuation (HU) as quantitative imaging biomarkers.
Methods or Background: We conducted a retrospective analysis of 1,499 colorectal cancer patients who underwent surgical intervention and had pre-operative abdomen CT scans at the level of the third lumbar vertebra. nnU-Net facilitated the automatic segmentation of SSAT, DSAT, VAT, and skeletal muscle. Both CSA and HU were measured. The evaluated outcomes comprised recovery duration, length of stay (LOS), readmission rates, complications (infectious, cardiovascular, surgical, paralytic ileus, wound dehiscence, anastomotic leak), and pre- and post-operative WHO performance status.
Results or Findings: SSAT and DSAT CSA and HU exhibited no significant correlations with outcomes. A diminished skeletal muscle cross-sectional area corresponded with inferior WHO performance status (p<0.001). Reduced muscle HU forecasted extended LOS (ρ=–0.106, p_fdr<0.001), postponed recovery (ρ=–0.082, p_fdr=0.011), and heightened complications (OR = 0.98perHU,p = 0.005). VAT exhibited a contradictory dual function: increased VAT CSA correlated with extended LOS (p<0.001), ileus (p_fdr < 0.001), and surgical complications (OR≈1.03per+10 cm², p = 0.025), yet diminished VAT CSA and low muscle mass signified frailty (p < 0.01). Increased VAT HU independently forecasted a heightened risk of complications (OR=1.01perHU,p=0.016) and an escalation in the severity of surgical and cardiovascular incidents.
Conclusion: CT body composition yields clinically significant biomarkers. Muscle (CSA, HU) reflects frailty and functional reserve, whereas VAT has a paradoxical role; elevated VAT indicates surgical risk, whereas diminished VAT alongside low muscle suggests frailty.
Limitations: Retrospective, single-cancer cohort; absence of external validation; and lack of long-term oncological outcomes.
Funding for this study: No Funding
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: institutional approval and ethics consent was obtained from the Institutional Review Board (IRB) with DSRB number 2023/00769