Correlation Between PET/CT Metabolic Parameters And Pathological Features Of Breast Cancer And Its Value In Predicting Lymph Node Metastasis

ObjectiveTo explore the correlation between 18F-FDG PET/CT metabolic parameters and pathological features in patients with breast cancer,and its application value in predicting ipsilateral axillary lymph node metastasis.MethodsA total of 78 patients with primary invasive breast cancer confirmed by pathology in our hospital from January 1,2019 to October 1,2022 were collected.All patients were examined by immunohistochemistry and PET/CT within two weeks before treatment.The clinicopathological information of the patients was recorded,such as menstrual status,age,lesion size,degree of differentiation,molecular classification,ipsilateral axillary lymph node metastasis,distant metastasis and the expression of estrogen receptor(ER),progesterone receptor(PR),human epidermal growth factor receptor-2(HER-2)and proliferating cell nuclear antigen(Ki-67).The PET/CT metabolic parameters of the lesions were measured,including maximum early standardized uptake value(SUVmax T),maximum delayed standard uptake value(SUVmax T2),mean standard uptake value(SUVmean T),peak standard uptake value(SUVpeak T),tumor metabolic volume(MTVT),total glycolysis(TLGT),and calculated the maximum standard uptake difference SUVmax T(SUVmax T2-SUVmax T).The differences among different clinicopathological characteristics were compared,and the correlation between them and clinicopathological features was analyzed.The metabolic parameters with statistical significance in the grouping of lymph node metastasis were analyzed by multivariate regression analysis,and a model for predicting lymph node metastasis was established.The ROC curve of the subjects’ working characteristics was drawn,and the best cut-off value was found by the method of maximum Jordan index.The patients were divided into low-risk group and high-risk group.In order to improve the diagnostic accuracy of ipsilateral axillary lymph node metastasis in patients with breast cancer,lymph nodes were taken as the object of study.The PET/CT metabolic parameters of visual lymph nodes,such as early maximum standard uptake value(SUVmax L1),delayed maximum standard uptake value(SUVmax L2),mean standard uptake value(SUVmean L),peak standard uptake value(SUVpeak L),tumor metabolic volume(MTVL),total glycolysis(TLGL),maximum standardized uptake value of liver(SUVmax H),maximum standardized uptake value of abdominal aorta(SUVmax A),long diameter(L)and short diameter(D)were measured and recorded.The maximum standard uptake ratio of lymph nodes / lesions(SUVmax L1/T),the maximum standard uptake ratio of lymph nodes / liver(SUVmax L1/H),the maximum standard uptake ratio of lymph nodes / abdominal aorta(SUVmax L1/A),the maximum standard uptake difference SUVmax L(SUVmax L2-SUVmax L1)and the ratio of length to short diameter(L > D)were calculated.To compare the difference of metabolic parameters between lymph node metastasis group and non-metastasis group,through multivariate analysis of lymph node PET/CT parameters with statistical difference,to explore the independent risk factors affecting lymph node metastasis,and to establish a joint prediction model.Draw the ROC curve of the prediction model and the traditional diagnostic criteria,and compare the difference of the area under the curve of the two diagnostic criteria of lymph node metastasis.Results1、The metabolic parameters of breast cancer patients with primary lesions ≥ 2.5cm were higher than those with lesions < 2.5cm(P < 0.05),and there was a significant difference in metabolic parameters among patients with different lesion size(rs=0.519,0.399,0.529,0.617,0.617 and 0.419,all P <0.05).The metabolic parameters increased with the decrease of differentiation degree,and there was significant difference in different differentiation degree groups(P < 0.05.There was a significant negative correlation between tumor differentiation degree and PET/CT metabolic parameters(rs=-0.626,-0.573,-0.665,-0.401,-0.555 and-0.583,all P < 0.05).2、The metabolic parameters of PET/CT in patients with distant metastasis were significantly higher than those without distant metastasis,and there was a significant positive correlation between distant lymph node metastasis and PET/CT metabolic parameters(rs=0.401,0.393,0.513,0.487,0.584 and 0.386,all P < 0.05).3、The metabolic parameters of ER and PR negative expression group were higher than those of ER and PR positive expression group.In ER positive expression group and ER negative expression group,there were significant differences in metabolic parameters SUVmax T,SUVmean T,SUVpeak T,SUVmax T(P < 0.05).There was a negative correlation between focus metabolic parameters SUVmax T,SUVpeak T,TLGT,SUVmax T and ER expression in breast cancer patients(rs=-0.271,-0.263,-0.224 and-0.323,all P < 0.05).4、The metabolic parameters of patients with Ki-67 positive expression were higher than those of patients with Ki-67 negative expression,and there were significant differences between the two groups(P < 0.05).The expression of Ki-67 was positively correlated with metabolic parameters of lesions(rs=0.449,0.500,0.456,0.403,0.498 and 0.246,all P < 0.05).There was a positive correlation between the expression of SUVmax T,SUVmean T,SUVpeak T,MTVT,TLGT and Ki-67 in the ipsilateral axillary lymph node metastasis group(P < 0.05),and between the expression of SUVmax T,SUVmean T,SUVpeak T,TLGT and Ki-67 in the non-metastasis group(P < 0.05).SUVmax T,SUVmean T,SUVpeak T and TLGT could predict the expression level of Ki-67,and the area under the curve was 0.807,0.843,0.812 and 0.841,respectively(P < 0.001).5、The levels of SUVmax T,SUVmean T,SUVpeak T and SUVmax T in HER-2 positive expression group were higher than those in HER-2 negative expression group,and there were significant differences in metabolic parameters SUVmax T,SUVmean T,SUVpeak T and SUVmax T between the two groups(P < 0.05).There was a significant positive correlation between metabolic parameters SUVpeak T,SUVmax T and HER-2 expression(rs=0.246 and 0.358,P < 0.05).6、In different molecular typing,the metabolic parameters were the highest in the triple negative group and the lowest in the Luminal A group.There were significant differences in SUVmax T,SUVmean T,SUVpeak T and TLGT among different molecular typing(P < 0.05).7、The metabolic parameters of primary focus in patients with ipsilateral axillary lymph node metastasis were higher than those without metastasis.There was significant difference in PET/CT metabolic parameters between patients with ipsilateral axillary lymph node metastasis and patients with ipsilateral axillary lymph node metastasis(P < 0.05).There was a significant positive correlation between ipsilateral axillary lymph node metastasis and PET/CT metabolic parameters(rs=0.360,0.282,0.389,0.376,0.381 and 0.396,all P < 0.05).PET/CT metabolic parameters affecting ipsilateral axillary lymph node metastasis were analyzed by multivariate analysis.The results showed that SUVpeak T was an independent risk factor for ipsilateral axillary lymph node metastasis of breast cancer.When SUVpeak T ≥ 6.24,patients could be divided into high risk group and low risk group when SUVpeak T < 6.24.8、The metabolic parameters of lymph nodes in the group with ipsilateral axillary lymph node metastasis were higher than those in the group without metastasis,and there was significant difference in the parameters of PET/CT metabolism in the group with ipsilateral axillary lymph node metastasis.Multivariate regression analysis showed that PET/CT metabolic parameters SUVmax L(X2),SUVpeak L(X3)and SUVmax L1/A(X4)were independent risk factors for ipsilateral axillary lymph node metastasis in breast cancer(P < 0.05).Therefore,a joint prediction model of lymph node metastasis was established and compared with the traditional PET/CT diagnostic criteria.It was found that the combined prediction model could improve the diagnostic efficiency of lymph node metastasis of breast cancer,and the diagnostic efficiency was significantly higher than that of the traditional PET/CT diagnostic criteria.Conclusions1、Taking primary breast cancer and lymph nodes as subjects,it was found that SUVpeak T,SUVmax L,SUVpeak L and SUVmax L1/A were independent risk factors for predicting ipsilateral axillary lymph node metastasis in breast cancer.The combined prediction model based on PET/CT metabolic parameters can improve the diagnostic efficiency of ipsilateral axillary lymph node metastasis of breast cancer,and the diagnostic efficiency is significantly higher than that of traditional PET/CT diagnostic criteria.2、The different metabolic parameters of PET/CT in primary breast cancer were related to the size of breast lesion,degree of differentiation,distant metastasis,ipsilateral axillary lymph node metastasis,expression of ER,PR,Ki-67,HER-2 and molecular classification.And the correlation between SUVmax T,SUVmean T,SUVpeak T,TLGT and Ki-67 is not affected by ipsilateral axillary lymph node metastasis,so it has a high predictive efficiency for the expression of Ki-67.