Ultrasound for the Objective Measurement of Breast Lymphedema

Breast lymphedema has supplanted upper extremity lymphedema as a common and debilitating sequela of breast cancer treatment, but has no objective measurement. We assessed the utility of ultrasound-measured difference in dermal thickness between affected and unaffected breasts as a measure of breast lymphedema. We associated this measure with patient characteristics, treatment parameters, and patient-reported impact on quality of life.

We enrolled 30 invasive breast carcinoma patients treated with breast-conserving surgery, sentinel lymph node biopsy, and radiotherapy, and 10 control patients evaluated for benign breast conditions without prior breast surgery or radiotherapy. Patient and treatment variables were ascertained from medical records and radiotherapy instruments. Impacts on quality of life were measured with a modified Disability of the Arm, Shoulder, and Hand questionnaire. We characterized breast lymphedema by calculating the difference in ultrasound-measured dermal thickness between affected and unaffected breasts. Associations with patient characteristics, treatment, and quality of life were quantified with log-binomial regression models.

Breast lymphedema was defined as a dermal thickness difference of >0.3 mm. Nineteen patients in the invasive group (63%) had breast lymphedema by this definition. We observed positive associations between ultrasound-defined breast lymphedema and surgical factors (size of primary tumor, number of lymph nodes removed), radiotherapy factors (breast volume irradiated, receipt of radiation boost), and patient-reported outcomes (sleep quality and overall confidence).

Difference in dermal thickness is an easy and inexpensive measurement for quantifying breast lymphedema, and correlates with treatment parameters and patient-reported impacts on quality of life.