Lymphoscintigraphy is frequently recommended but seldom used in a "real world setting"

Lymphedema (LED) lacks a standard, simple, guiding noninvasive diagnostic test, unlike the two other circulatory disorders-arterial or venous disease. Lymphoscintigraphy (LSG) has been recommended by several guidelines as the diagnostic test of choice for LED. Several recent expert panels, however, have suggested from anecdotal experience that LSG was used infrequently, and that the diagnosis of LED is usually based on clinical examination.

To determine the use of LSG in a large real-world LED population, the International Business Machines MarketScan Research Database was examined from April 2012 to March 2020 for patients with a new diagnosis of LED (the index date). Use of LSG (LSG+) was ascertained during the period beginning 12 months prior to the initial coding of a LED diagnosis and ending 12 months after the index date based on the corresponding Current Procedural Terminology code; LSG use for sentinel node mapping at the time of oncologic surgery was excluded. Demographic profiles, comorbidities, and causes of LED among patients with and without evidence of LSG were characterized.

We identified 57,674 patients, aged ≥18 years, who had a new diagnosis of LED and health care coverage for ≥12 months before and after this index date. Only a small number (1429; 2.5%) of these patients underwent LSG during the study period. The LSG + cohort was younger (53.7 vs 60.7 years), had a higher proportion of women (91.3% vs 73.4%), but a lower percentage of diabetes (12.8% vs 27.5%), heart failure (2.2% vs 8.7%), hypertension (32.4% vs 51.0%), and obesity (15.1% vs 22.2%) compared with the LED population who did not undergo LSG (all P < .001). Most importantly, the use of LSG for diagnosis varied with the etiology of LED (LSG was most frequently utilized among patients with melanoma-LED (9.5%) and patients with breast cancer-LED (6.7%), in contrast to patients with advanced venous disease-related LED (1.1%; P < .05 for both comparisons).

Despite four guidelines recommending LSG, including the Guidelines of the American Venous Forum (Handbook of Venous and Lymphatic Disease-4th edition), which recommended LSG "for the initial evaluation of patients with LED" with a 1B recommendation, LSG plays a minor role in establishing the diagnosis of LED in the United States. This underlines the need for a better, simple diagnostic test for LED to complement clinical examination.