Characterizing Forearm Skeletal Muscle Composition and Function in Breast-Cancer Related Lymphedema Using B-Mode Ultrasonography

Little is known about skeletal muscle thickness, echogenicity, and muscle quality (handgrip strength /muscle thickness) in breast cancer-related lymphedema (BCRL). Using B-mode ultrasound, we recorded the raw radiofrequency data of the affected (AA) and unaffected (UA) arms of women (n=20) with BCRL, and in 20 control women with no lymphedema (CA). The data were converted into images and measurements of skin, subcutaneous fat and muscle thickness were obtained. Within a designated region of interest, muscle echo-intensity was assessed using computer graded grey scale and muscle thickness was measured using ImageJ2. Handgrip strength was measured using standard dynamometry. We found that forearm muscle thickness was similar among AA, UA, and CA. When compared to the unaffected and control arms, the affected arm had a significantly higher (p 0.013) muscle echo-intensity. When compared to the AA, handgrip strength was similar to UA (p 0.401) but lower than CA (p 0.05). We conclude that the use of B-mode ultrasound is a reliable method to assess muscle thickness and EI in BCRL. When comparing AA to UA, the elevated levels of muscle EI in AA did not influence strength or muscle quality. The elevated EI in AA is a marker of abnormal health that needs to be further explored.