The Value Of ⁶⁸Ga-NOTA-Evans Blue PET/MR Lymphoscintigraphy On Evaluation Of The Severity Of Lower Limb Lymphedema

Purpose:This study was designed to investigate the role of 68Ga-NOTA-Evans Blue(NEB)positron emission tomography/magnetic resonance(PET/MR)in evaluating lower limb lymphedema by visual analysis and novel parameters.Methods:Thirteen patients with unilateral lower limb lymphedema were divided into 3 groups according to the clinical severity:minimal(4 patients),moderate(5 patients),and severe(4 patients).All patients underwent 68Ga-NEB PET/MR lymphoscintigraphy.The ratio of superficial lymphatic vessel(SLV)'s Standardized uptake value(SUV)vs deep lymphatic vessel(DVL)'s SUV(SUVslv/dlv)was designed to assess the level of lymphedema severity.The correlation between lymphedema severity and lymphoscintigraphy findings was determined using one-way analysis of variance,the t test,and Pearson correlation analysis.Results:1.Compared with SPECT lymphoscintigraphy,68Ga-NEB PET/MR lymphoscintigraphy could clearly reveal deep and superficial lymphatic vessels and lymph nodes of bilateral lower limbs,and indicate the edema and fibrosis of subcutaneous tissue.2.There was a significant difference in the SUVslv between the affected limbs and normal limbs in all subjects(affected limbs:0.57±0.32,normal limbs:1.86±1.43,P<0.05),which was not found in the SUVdlv(affected limbs:0.64±0.39,normal limbs:0.63±0.31,P>0.05).3.The SUVslv/dlv of the affected limbs showed statistical differences within the three groups(P<0.05)(minimal group:1.91±0.45;moderate group:0.84±0.16;severe group:0.42±0.11).The statistical analysis revealed a negative correlation between SUVslv/dlv and the severity of lymphedema(r=-0.899,P<0.01).Conclusions:68Ga-NEB PET/MR lymphoscintigraphy can provide anatomical and functional information of lymphatic vessels to guide surgery personalized plans.SUVslv/dlv was well correlated with clinical lymphedema severity and might be potential in evaluating bilateral lower limb lymphedema.