Linear Muscle Segmentation for Metastatic Renal Cell Carcinoma: Changes in Clinic-Friendly Estimation Predict...

Area of Science:

• Oncology
• Surgical Oncology
• Radiology

Background:

• Sarcopenia and muscle mass changes impact survival in metastatic renal cell carcinoma (mRCC) patients undergoing cytoreductive nephrectomy (CN).
• Linear segmentation offers a rapid, clinic-friendly method for assessing muscle mass.
• Preoperative and postoperative muscle mass dynamics are crucial for predicting patient outcomes.

Purpose of the Study:

• To investigate the association between preoperative and postoperative muscle mass changes, assessed by linear segmentation, and survival outcomes in mRCC patients after CN.
• To determine if maintaining muscle mass or experiencing muscle loss/gain post-surgery influences cancer-specific survival (CSS) and overall survival (OS).

Main Methods:

• Retrospective review of 205 mRCC patients who underwent CN.
• Linear segmentation of psoas/paraspinal muscles for baseline (pre-op) and postoperative imaging.
• Statistical analysis using Kruskal-Wallis, Fisher's exact test, and multivariable Cox proportional hazards models to assess muscle index changes and survival.

Main Results:

• 25.4% had stable muscle mass (LMI change < 5%), 29.3% increased, and 44.9% decreased.
• Patients with stable muscle mass (0Δ LMI) had significantly longer median CSS (133.6 months) and OS (67.2 months) compared to those with muscle increase or decrease.
• Stable LMI was a significant protective factor against cancer-specific mortality (CSM) and all-cause mortality (ACM).

Conclusions:

• Postoperative changes in muscle mass, quantified by linear muscle segmentation, are independently associated with survival in mRCC patients after CN.
• A lack of significant change in muscle mass post-CN is associated with improved overall and cancer-specific survival.
• Linear segmentation is a valuable tool for assessing muscle mass dynamics and predicting outcomes in this patient population.