Lymphoscintigraphy is used to confirm the diagnosis of lymphedema; pathologic findings are abnormal transit time to regional nodes and dermal backflow. A universal protocol for the test does not exist. The purpose of this study was to determine whether the clinical severity of lymphedema correlates with lymphoscintigraphy findings.

Patients treated in our Lymphedema Program between 2009 and 2017 were reviewed. Diagnosis of lymphedema was determined by history, physical examination, and lymphoscintigraphy. Severity was defined by increased volume of the limb as follows: mild (<20%), moderate (20% to 40%), and severe (>40%). Candidate variables included location (arm, leg), age, duration of symptoms, infection history, and lymphedema type (primary, secondary). An association between lymphedema severity and lymphoscintigraphy findings was determined using the Pearson chi-square test and multivariate logistic regression.

One hundred and thirty-four patients with 181 affected extremities (24 upper, 157 lower) were included. Clinical severity was as follows: 54% mild, 30% moderate, and 16% severe. Delayed tracer transit to the regional nodes was as follows: 45 minutes (34%), 2 hours (18%), and 4 hours or longer (48%). Thirty-six percent of extremities demonstrated dermal backflow. Abnormal transit time or dermal backflow was identified in 97% of extremities by 45 minutes and in 3% of limbs by 2 hours. Transit time and dermal backflow were not predictive of clinical severity when adjusting for candidate variables (p > 0.1).

Clinical severity of lymphedema is not associated with lymphoscintigraphy findings. A lymphoscintigram should be interpreted as normal or abnormal, and does not need to exceed 2 hours.