Quality of skeletal muscles during allogeneic stem-cell transplantation: a pilot study.

Objectives: This study investigated the muscle fat fraction (FF) and muscle-related parameters before and after allogeneic hematopoietic stem cell transplantation (HSCT).

Methods: Fat and water signals were derived from the in-phase and out-of-phase MR signal intensities of the pelvis and thigh using the two-point Dixon technique. They were analysed using Synapse Vincent, and muscle quality was evaluated using the FF. The muscle mass was assessed by measuring the thigh and gluteal muscle areas using a manual trace on the MR image. The association between the muscle FF and clinical data was retrospectively determined.

Results: This study included 11 patients (6 males). Their mean age was 42.7 years, and eight had leukaemia. Eight were assessed at a mean of 65.4 days post-HSCT. The hip and thigh skeletal muscle FFs were not significantly different during HSCT. The grip and lower limb muscle strengths decreased significantly after HSCT. Patients with low FFs before transplantation tended to lose muscle strength, and the increase in FF and decrease of muscle strength were correlated.

Conclusions: Muscle strength and quantity decrease during the early phase after HSCT, especially in patients with low FF muscles. Therefore, interventions based on muscle quality and quantity are essential.