LAUSR

Breast cancer–related lymphedema (BCRL) is a chronic disease that results from a disruption or obstruction in the lymphatic system and affects 15 in 100 individuals in the USA with newly diagnosed breast cancer. As no curative therapy exists for lymphedema, early detection is crucial in order to reduce the risk of developing late stage symptoms, such as swelling, decreased limb flexibility, disfigurement, and impaired function of the extremity. The objective of this review is to discuss current modalities and devices as well as highlight promising advancements intended to aid in diagnosing secondary lymphedema in breast cancer patients. Imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) can offer high resolution of the lymphatics but are expensive and time-consuming. Single photon emission computed tomography (SPECT) is an alternative that reveals organ function as opposed to organ structure. Other imaging methods, such as color duplex ultrasound (CDU), laser scanner 3D (LS3D), and dual-energy X-ray absorptiometry (DXA), are relatively easy to use, reproducible, and fast to perform. However, the disadvantages of these techniques include lower sensitivity and specificity compared with CT and MRI. Of note, direct imaging techniques are highly effective for the diagnosis of lymphedema because they utilize dyes or radiotracers in order to directly visualize lymphatic vessels. Fluorescent microlymphography (FMLG) and near-infrared imaging (NIR) involve injection of fluorescent dyes that can be excited with light. Lymphoscintigraphy has effectively replaced lymphangiography as the method of choice for the diagnosis of lymphedema because it is safer, less invasive, and has no risk of causing an allergic reaction in patients. Novel approaches that are currently in development include bioimpedance spectroscopy, ultra-high-frequency ultrasound systems (UHFUS), and magnetic resonance lymphography (MRL). The wide range of diagnostic methods for BCRL exhibit the tradeoff between simplicity and sensitivity; some techniques provide high resolution but are expensive and time consuming. On the other hand, other modalities are easy to use, reliable, and relatively fast in execution yet lack the ability to precisely visualize the lymphatic system. In review of these various techniques, lymphoscintigraphy serves as a clear gold standard for diagnosing secondary lymphedema while more advanced and promising techniques continue to emerge as newer alternatives in clinical practice.