Lymphoscintigraphy for the evaluation of pediatric lymphatic abnormalities

Objectives Lymphoscintigraphy has proven to be an useful method for the evaluation of lymphatic drainage in lymphedema and in sentinel node detection . In the pediatric setting, only a few cases of chylothorax/chyloperitoneum and lymphatic malformations imaged with lymphoscintigraphy, have been reported . The aim of this study was to review the value of lymphoscintigraphy in the evaluation of such abnormalities.

Methods A retrospective review was performed of all lymphoscintigraphies obtained between 2001 and 2013 in our hospital . Results were correlated to clinical and radiological findings. Lymphoscintigraphy consisted of sequential imaging over a period of 60 to 120 minutes after injection of 100-250 Uci Tc99m-filtered sulfur colloid in the interdigital spaces of the feet and/or hands . Delayed imaging was performed if needed.

Results Out of 121 lymphoscintigraphies performed during that period, 24 were done to evaluate lymphatic system abnormalities in 19 patients. Fourteen studies were obtained for the evaluation of chylothorax including 9 in patients post cardiac surgery . Ten were performed for chyloperitoneum (1), intestinal lymphangiectasia (2) and lymphangiomatosis (7). Eleven studies were positive for lymphatic leak ( 5 chylothorax, 2 chyloperitoneum and 4 lymphatic malformations ) , 2 were dubious : one without definite diagnosis and one with proven lymphangiectasia. After correlation with radiological findings and follow-up , of the 11 negative studies, 6 were true negative. Five studies were considered false negative. One had high background from a previous gallium scan interfering with imaging. Three had injections on the hands only .The study was repeated in one patient and was positive after injecting on the feet . For the last patient, the first study was negative under a normal diet but became positive after switching to a high lipid diet.

Conclusions Lymphoscintigraphy is an useful tool to image lymphatic abnormalities in children . Optimization of the technique include systematic injection of the 4 extremities and a high lipid diet .