RESUMEN
The objective of this study was to explore the possible association between low skeletal muscle mass (SMM)-assessed by computed tomography (CT) and ultrasound (US)-and hematologic toxicity in cancer patients. A prospective cohort study was conducted in cancer patients who received anthracycline-based chemotherapy between 2018 and 2020 and who had baseline abdominal CT including L3 level for measuring SMM. Regional muscle measurements were carried out using US. A total of 65 patients (14 males, 51 females) were included. ROC (receiver operating characteristic) analysis identified threshold values of 18.0 mm [AUC (area under the curve) = 0.765] for females and 20.0 mm (AUC = 0.813) for males, predicting severe neutropenia. Using these cut-offs, females with low rectus femoris (RF) thickness (<18.0 mm) had a significantly higher incidence of grade ≥3 neutropenia (50.0% vs. 10.8%, p = 0.005), and males with low RF values (<20.0 mm) had a higher incidence (80.0% vs. 22.2%, p = 0.063). A regression analysis, irrespective of age, gender, and body mass index, revealed that only low RF muscle thickness increased the risk of grade 3-4 neutropenia by 9.210 times (95% CI = 2.401-35.326, p = 0.001). Utilizing US to measure RF muscle thickness aids in identifying cancer patients at an elevated risk of developing neutropenia. Needless to say, US can serve as a convenient and easily accessible tool for assessing low SMM, providing repeat point-of-care evaluations in clinical practice.