SARCOPENIA TRONG UNG THƯ VÀ CÁ THỂ HÓA CHIẾN LƯỢC XẠ TRỊ BẰNG ĐIỆN TRỞ KHÁNG SINH HỌC

Abstract

Background: Sarcopenia is characterized by reduced muscle strength accompanied by reduced muscle quantity and/or quality. It is common in patients with cancer and is associated with adverse clinical outcomes, treatment toxicity and reduced treatment tolerance. Body weight and BMI do not directly reflect body composition and may miss low muscle mass, particularly in patients with overweight or obesity. Bioelectrical impedance analysis (BIA) is non-invasive, rapid and repeatable, but its estimates are influenced by hydration status, device characteristics and prediction equations.

Objective: To review the role of sarcopenia in cancer, compare body composition assessment methods, clarify the clinical value and limitations of BIA, and define the current level of evidence for using BIA to support personalized radiotherapy.

Overview: Sarcopenia is associated with adverse outcomes across several cancer populations and with selected outcomes during radiotherapy. CT is widely used for quantitative assessment of skeletal muscle, while DXA provides reproducible assessment of lean mass. BIA estimates skeletal muscle mass, skeletal muscle index (SMI) and phase angle with lower cost and greater convenience. Some validation studies have demonstrated substantial agreement or correlation between BIA and reference methods, including DXA, in selected populations; however, results are not interchangeable across devices, equations and clinical conditions. The major practical advantage of BIA is that it can be performed rapidly and repeated over time. This may identify changes in muscle mass that are not apparent from body weight or BMI alone. However, BIA does not directly measure muscle mass and accuracy may be reduced by edema, ascites, dehydration, rapid fluid shifts, obesity, or differences between devices and prediction equations. BIA is therefore best considered a screening and monitoring tool whose results are integrated with muscle strength, physical performance and clinical context. Current evidence is insufficient to use BIA parameters independently to modify radiotherapy dose or replace anatomical and dosimetric parameters used for treatment planning.

Conclusion: Sarcopenia is an important risk marker in patients with cancer. BIA has potential value for detecting and monitoring changes in body composition, particularly when repeated assessment is required. By adding information on muscle mass and body composition beyond body weight or BMI alone, BIA may improve risk stratification and support individualized nutritional, rehabilitation and oncologic care. Its current role in radiotherapy personalization is supportive rather than an independent basis for modifying radiation dose.