Abstract

Background Skeletal muscle is critical for functional status, quality of life, and treatment tolerance in pediatric patients with cancer. Traditional assessments of muscle mass involve radiation and are often unsuitable for frequent monitoring. Ultrasound (US) is noninvasive and radiation-free; however, its reliability in pediatric patients with cancer, who experience rapid changes in body composition, is not well established. This study aimed to determine the interrater reliability of US for measuring key muscle parameters.Methods A novice and an expert sonographer blindly measured muscle thickness (mT), cross-sectional area (CSA), and echo intensity (EI) for the quadriceps femoris (QF) and tibialis anterior (TA) muscles in an oncology group and a healthy group. Interclass correlation coefficients were calculated to assess interrater reliability.Results A total of 27 participants were included (n = 14 oncology and n = 13 healthy). All quadriceps measures had good reliability, with QF mT = 0.895 (95% CI, 0.77-0.952), rectus femoris (RF) mT = 0.881 (95% CI, 0.74-0.946), CSA = 0.801 (95% CI, 0.563-0.909), and EI = 0.839 (95% CI, 0.647-0.927). All TA measures had excellent reliability: mT = 0.968 (95% CI, 0.929-0.985), CSA = 0.925 (95% CI, 0.835-0.966), and EI = 0.909 (95% CI, 0.801-0.959). The oncology group's reliability remained high. Key results included RF mT = 0.906 (95% CI, 0.706-0.970), QF mT = 0.887 (95% CI, 0.646-0.964), TA mT = 0.972 (95% CI, 0.912-0.991), CSA = 0.947 (95% CI, 0.836-0.983), and EI = 0.943 (95% CI, 0.822-0.982).Conclusion Point-of-care US is a reliable method to measure muscle in pediatric oncology patients. Moreover, novice sonographers can be trained to perform these measurements reliably.