Abstract
There have been substantial recent advances in the noninvasive objective documentation of lymphedema, both in relation to detection and to quantitative assessment of severity.
In this issue of Lymphatic Research and Biology, three unrelated articles address various aspects of this topic. In the first of these, Niwa and colleagues describe their ability to ultrasonographically detect subcutaneous fluid accumulation in the upper extremities of breast cancer patients. They performed imaging studies on 20 patients with breast cancer-associated lymphedema. Fluid accumulation, as detected by texture analysis, was observed using a 3-Tesla MR system under double-echo steady-state conditions. The authors describe their ability to identify seven distinct textural features of the subcutaneous tissue that permit ultrasonographic detection of lymphedema.
For the lower extremities, Zarrad and colleagues describe the utility of skin layer thickness measurements and shear wave elastography to objectively document the impact of intensive decongestive treatment. In 47 subjects, the authors measured circumferences, epidermis, dermis, and subcutis layer thickness with B-mode ultrasonography, and subcutis elastic modulus with ultrafast shear wave velocity (ultrasound elastography), at five anatomical levels, before and after a short course of intensive decongestive therapy. In addition to treatment-related reduction in circumference, the reduction in subcutis measurements proved to be reliable and correlated with the observed increases in the elastic modulus. The latter changes are presumed to reflect the increase in tissue stiffness that results from fluid evacuation from the tissues.
Finally, Liu et al. describe the utility of the tissue dielectric constant, combined with upper limb volume measurements, in the detection and assessment of breast cancer-related lymphedema. Use of the tissue dielectric constant to detect subcutaneous edema has been repeatedly described within the pages of this journal.1–13 In this study, as well, the authors describe the utility of this objective measure for the detection of edema.
Although further evaluation and scrutiny are necessary, these three articles suggest that imaging and other approaches will have increasing applicability in the surveillance and treatment of our patients with, and at risk for, lymphedema in years to come.