Comparison of lymphoscintigraphy and indocyanine green lymphography for the diagnosis of extremity lymphoedema

SummaryBackgroundLymphoscintigraphy is the gold-standard examination for extremity lymphoedema. Indocyanine green lymphography may be useful for diagnosis as well. We compared the utility of these two examination methods for patients with suspected extremity lymphoedema and for those in whom surgical treatment of lymphoedema was under consideration.MethodsA total of 169 extremities with lymphoedema secondary to lymph node dissection and 65 extremities with idiopathic oedema (suspected primary lymphoedema) were evaluated; the utility of indocyanine green lymphography for diagnosis was compared with lymphoscintigraphy. Regression analysis between lymphoscintigraphy type and indocyanine green lymphography stage was conducted in the secondary lymphoedema group.ResultsIn secondary oedema, the sensitivity of indocyanine green lymphography, compared with lymphoscintigraphy, was 0.972, the specificity was 0.548 and the accuracy was 0.816. When patients with lymphoscintigraphy type I and indocyanine green lymphography stage I were regarded as negative, the sensitivity of the indocyanine green lymphography was 0.978, the specificity was 0.925 and the accuracy was 0.953. There was a significant positive correlation between the lymphoscintigraphy type and the indocyanine green lymphography stage. In idiopathic oedema, the sensitivity of indocyanine green lymphography was 0.974, the specificity was 0.778 and the accuracy was 0.892.ConclusionIn secondary lymphoedema, earlier and less severe dysfunction could be detected by indocyanine green lymphography. Indocyanine green lymphography is recommended to determine patients' suitability for lymphaticovenular anastomosis, because the diagnostic ability of the test and its evaluation capability for disease severity is similar to lymphoscintigraphy but with less invasiveness and a lower cost. To detect primary lymphoedema, indocyanine green lymphography should be used first as a screening examination; when the results are positive, lymphoscintigraphy is useful to obtain further information.