Correlation Study Of3.0T MRI On Breast Cancer And Axillary Lymph Node Metastasis

Background:Breast cancer has become the most accessible malignanttumors in women,and the incidence is varous from7%-10%of all the systemicmalignant tumors.Axillary lymph node metastasis is an independent factor inthe prognosis of patients with primary breast cancer,and is particularlyimportant to the clinical staging、treatment and surgery.Axillary lymph nodedissection is the only reliable means to distinguish the metastasis of lymphnode,but it has been confirmed by pathology that a significant proportion ofpatients did not have metastasis.Recent studies have shown that sentinel lymphnode biopsy can accurately predict axillary lymph node status,but it requiresdeep skills and experience,and the problem of false negative has not beensolved well. Therefore,how to conduct accurate prediction and quatitativediagnosis of axillary lymph node status in high risk patients before surgery toidentify patients with high metastatic risk has become a new hotpot.Objective: To study the correlation between MR features of primarybreast cancer and axillary lymph node metastasis,and assess the diagnosticvalue of MR in the metastasis of lymph node to provide a reliable basis forclinical diagnosis and treatment of breast cancer.Materials and methods: This study adopts a retrospective study of40cases from January2010to December2011,who have undergone MR scan anddynamic enhanced scan with Siemens3.0T MR machine in Norman BethuneFirst Hospital of Jilin University,and are confirmed to be primary breastcancer.We use sentinel lymph node biopsy or axillary lymph node dissectionpathology results after surgical resection of tumor as the gold standard, andrecord the MR findings of breast cancer tumor and axillary lymph node, including the location, the largest diameter, shape, and strengthen time-signalcurve and the long diameter, short diameter, diameter ratio, T2STIR fatty hilumdisappearance or not of axillary lymph node. For all data were analyzed bySPSS17.0statistical software,using univariate and multi-factor logisticregression to analyse the correlation between the observed indicators andaxillary lymph node metastasis, and use the kappa test to evaluate theconsistency of the observed indicators and pathological results.Results:(1)The single factor analysis of tumors signs and axillary lymphnode shows: there are significant differences in the maximal tumor diameter,time-signal enhancement curves (P<0.01), and they have a good agreementwith the pathological results (k=0.57~0.679, P <0.01); there is no significantdifference in site, shape of primary tumor between the metastatic group andnon-metastatic group (P>0.05).(2) The single factor analysis of axillarylymph node MR signs and axillary lymph node metastasis shows: there aresignificant differences in the length diameter of lymph node (1.0cm line), thelength diameter ratio, T2STIR fatty hilum (P<0.02),and the length diameterratio has a good fit degree with the pathology results (k=0.518, P<0.01).However,there shows a poor fit degree that we only use long diameter≥1.0cmand T2STIR sequences with fat door disappearence to diagnose axillary lymphnode metastasis and pathologic findings (k values are0.398and0.158separately, both P<0.01); there is no statistical significance with long diameter0.5cm line for judging axillary lymph node metastasis (P>0.05).(3)Themultiple factors analysis of logistic regression analysis of axillary lymph nodemetastasis shows:the maximum tumor diameter, TIC curve and long diameterare risk factors for breast cancer patients with axillary lymph nodemetastases,and it has a close relationship with lymph node metastasis (allP<0.05). When length diameter ratio alone is included in regression analysis,there is a certain correlation between length diameter ratio and lymph node metastasis (P<0.05).Conclusion:(1) The largest diameter of breast cancer lesions and MRtime-signal curve is closely related to axillary lymph node metastasis: thelarger the largest diameter of breast cancer lesions is, the greater the probabilityof axillary lymph node metastasis occurs; patients who have the time-signalcurve with a suddendrop type have a greater probability of axillary lymph nodemetastasis.(2) MR characteristics,such as the location and shape changes ofbreast lesions can provide certain tips to judge the axillary lymph nodemetastasis.But there exsits limitations, we need to expand the sample size forfurther explore.(3) There are limitations only using shape or morphologicalchanges to evaluate axillary lymph nodes.Therefore, we need tocomprehensively considerate MR findings of the breast tumor and axillarylymph nodes to help improve the accuracy rate of the MR diagnosis of axillarylymph node metastasis and determine the axillary lymph node status moreaccurately.