Reliability and validity of ultrasound to measure of muscle mass following allogeneic hematopoietic stem cell transplantation.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients frequently show physical dysfunction due to loss of muscle mass. This study aimed to clarify the reliability and validity of ultrasound in evaluating muscle mass and to analyze the patterns of change in muscle mass before and after allo-HSCT. We conducted a prospective observational study using data from 68 patients who had undergone their first allo-HSCT. We evaluated the thickness of the quadriceps, biceps, and suprahyoid muscle. Three individual evaluators underwent this examination for each muscle before transplantation and on days 30, 90, and 180 after allo-HSCT. Inter-rater reliability was calculated using the interclass correlation (ICC), and the level of correlation between muscle mass measured by ultrasound and psoas muscle mass assessed using computed tomography (CT) was assessed using Pearson correlation. ICC values ranged from 0.897 to 0.977 in the measurement. The correlation scores were 0.730, 0.546 and 0.579 between psoas muscle and the biceps, quadriceps, and suprahyoid muscle. The thickness of the biceps and quadriceps muscle were both significantly decreased after allo-HSCT from baseline. These results showed that the ultrasound technique was a reliable tool for evaluating muscle mass and detecting changes in muscle mass following allo-HSCT.