Reliability of Lymphoscintigraphy

To the Editor

We read with great interest the recent article entitled “Reproducibility of Lymphoscintigraphic Evaluation of the Upper Limb” by Devoogdt and colleagues. ¹ These authors found that lymphoscintigraphy was a reliable technique (ICC=0.75 to 0.85) for the assessment of lymphatic function variables such as lymph node number and dermal backflow.

The authors state in their discussion that “To our knowledge, this is the first study investigating the reproducibility of the quantitative lymphoscintigraphic evaluation of the upper limb”. We would like to draw the attention of readers to the article by Dylke et al. ² that reports the outcome of a similar but larger study (53 subjects and 13 assessors). These authors also found similar levels of reproducibility in the assessment of dermal backflow (Fleiss κ=0.418) but that intra-observer reliability when blindly re-assessing the same images was variable, ranging from poor to perfect.

Both these studies suggest that lymphoscintigarphy is a technique that is generally reliable and that clinicians can be reasonably confident in conclusions drawn from assessment of lymphoscintigraphic images. However, such conclusions should not be considered definitive and should be used for diagnosis or clinical decision-making only in conjunction with other assessment modalities.

Both studies, we hope, will provide the stimulus for further research leading to standardization of lymphoscintigraphy procedures for the study of the lymphatic system.