Ultrasound and Clinical Measures for Lymphedema.

Abstract

Treatment for breast cancer has increased patient survivorship exponentially over the past few decades. With increased survivorship, more women are living with the longstanding effects of breast cancer treatment, such as lymphedema. Patients, health care providers, and payers depend on practical and efficient clinical measures to accurately diagnose and monitor disease progression or regression. However, current clinical measures do not include objective measures that assess lymphedetamous tissue accurately. This study compared current measures to a novel use of ultrasound (US) imaging to quantify tissue texture. Seventeen women diagnosed with lymphedema completed self-report questionnaires and then were tested twice by two lymphedema physical therapists who measured edema, fibrosis, and limb volume differences. One therapist measured subjects' limbs using US imaging and derived measures of entropy and average pixel intensity. Volume measures were consistent between therapists (p < 0.01) but palpation was not (0.01 < p < 0.72). Therapists' measures correlated better to subjects' self-report of edema (0.01 < p > 0.32) as compared to fibrosis (0.23 < p > 0.90). US measures were reliable (Cronbachs's α = 0.7 and 0.91 for entropy and API, respectively). Entropy measures demonstrated significant differences between subjects' involved versus uninvolved forearms (p = 0.03). Therapists were not consistent with each other when rating edema or fibrosis; however, they were consistent when measuring limb volume differences. US measures (entropy) demonstrated a significant difference between involved and uninvolved. US imaging, as a tool to quantify subcutaneous tissues, holds promise to be a safe, mobile, and effective method to measure lymphedema tissue texture.