The association of axillary lymph node-positive breast cancer with metabolic parameters of 18F-fluorodeoxyglucose PET / CT

Objective: This study aims to examine the association between 18F-fluorodeoxyglucose PET/CT (18F-FDG PET/CT) metabolic parameters of lymph node-positive and lymph node-negative breast carcinomas. Material and method: We included breast carcinomas patients who underwent 18F-FDG PET/CT imaging at our department between May 2018 and December 2019. A total of 108 female breast cancer patients were included (aged 48.8 ± 13.6years; range, 28-84 years). PET scanning was performed in 3D mode from the skull ceiling to the half of the thigh. According to pathology reports, we divided the patients into two groups: a lymph node-positive group of patients and a lymph node-negative group of patients. We calculated the sensitivity and specificity for determining the PET/CT pathological lymph node. Metabolic parameters like TLG (Total lesion glycolysis), MTV (Metabolic tumor volume), SUVmean, and SUVmax values were calculated. Result: The lymph node-positive group’s body weight and body mass index(BMI) were statistically higher than the lymph node-negative group (p=0,027,p=0,022 respectively). SUV max and SUV mean of the lymph node-positive group were statistically higher than the lymph node-negative group (p=0.008, p=0,009, respectively). Both TLG and MTV of the lymph node-positive group were statistically higher than the lymph node-negative group (p=0.01, P= 0.01, respectively). Ki-67(%) of the lymph node-positive group was not statistically different from the lymph node-negative group. We calculated the PET/CT’s sensitivity and specificity as 78,57% and 59,09%, respectively.  For the positive predictive value of PET/CT, we found 55%, and for the negative predictive value, it was 81.25%. Conclusions: PET/CT metabolic parameters of patients with lymph node-positive breast cancer were higher than patients with lymph node-negative. High body weight and BMI appears to increase the possibility of metastases of lymph node. The sensitivity of PET/CT can be considered to be useful in determining the pathological lymph node, but the specificity of PET/CT is not very good.