68Ga-NOTA-Evans Blue PET/CT findings in lymphangioleiomyomatosis compared with 99mTC-ASC lymphoscintigraphy: a prospective study.

BACKGROUND Lymphangioleiomyomatosis (LAM) is a rare multisystem disease characterized by cystic lung disease and extrapulmonary manifestations, including lymphatic system disorder. The objective of this study was to investigate the findings of 68Ga-NOTA-Evans Blue (NEB) PET/CT in LAM and compare it with that of 99mTc-ASC lymphoscintigraphy. METHODS Ten patients diagnosed with LAM according to the American Thoracic Society/Japanese Respiratory Society guidelines for LAM were recruited in this study. PET/CT acquisition was performed at 20 to 40 min after subcutaneous injection of 68Ga-NEB into the first interdigital spaces of both feet (0.3 ml, 37 MBq/foot). All subjects also underwent 99mTc-antimony sulfide colloid (ASC) lymphoscintigraphy within a week for comparison. RESULTS 68Ga-NEB PET/CT displayed various lymphatic system abnormalities in 10 (100%) of 10 patients. These included pulmonary lymphatic abnormalities in 10 (100%) of 10 patients, enlarged lymph nodes in 5 (50%), lymphangioleiomyomas in 2 (20%), dilation of the lumbar trunk and/or iliac lymph vessels in 5 (50%), thoracic duct dilation in 2 (20%), chylous effusion in 1 (10%). For pulmonary lymphatic abnormalities, the positive rates of 68Ga-NEB PET/CT and 99mTc-ASC lymphoscintigraphy were 100% (10/10) and 10% (1/10), respectively (P < 0.001). As for the 7 patients with extrapulmonary lymphatic manifestations, 68Ga-NEB PET/CT also presented more information than 99mTc-ASC lymphoscintigraphy. CONCLUSION 68Ga-NEB PET/CT visualized pulmonary lymphatic abnormality and displayed extrapulmonary lymphatic system disorders of LAM, and might play a role in the diagnosis and evaluation of the disease. 68Ga-NEB PET/CT is advantageous over conventional 99mTc-ASC lymphoscintigraphy in LAM by providing more detailed information of lymphatic dysfunction.