The Role Of ¹⁸F-FDG PET/CT In The Diagnosis Of Primary Breast Cancer,Monitoring Metastasis And Evaluating Prognosis Of Postsurgical Breast Cancer

【Objectives】1.To assess the accuracy of ¹⁸F-FDG PET/CT in the diagnosis of primary breast cancer;2.To assess the role of ¹⁸F-FDG PET/CT in monitoring metastasis of postsurgical breast cancer and to determine the value of PET in the evaluation of their prognosis.【Methods】We included 49 patients with breast cancer and 29 with benign breast disease in the first part.Two experimental doctor specialized in nuclear medicine made the diagnosis by visual analysis or semi-quantiative analysis separately.And it was compared with the final pathological results and clinical follow-up information.120 patients of postsurgical breast cancer were included in the second part.And all the patients had underwent pathological examination or had been observed by imaging madalities or clinical follow-up process.SUVmax、MTV and TLG were measured,which were further employed to determine whether or not did MTV and TLG correlate with their clinical and pathological characteristics and the patients’survival outcomes.【Results】Of all the patients with breast lesions,in terms of lesion analysis with visual method,sensitivity and specificity were 92.2%and 93.3%.In ROI semi-quantitative analysis of with the optimal threshold method SUVmax（cut-off value）of 3.15,sensitivity and specificity were 92.2%and 96.7%.Consistency between these two methods was 0.974.In correlation analysis of the factors of SUV,regression analysis showed that the maximum diameter of breast mass significantly correlated with the SUVmax,and the age and menopausal status were not relevant to and the degree of¹⁸F-FDG uptake in patients.Measured by immuno-histochemistry method,the tumor proliferation index ki67 was significantly associated with SUVmax value in primary breast cancer.However,hormone receptors ER,PR and Her2,p53 status were not relevant to the degree of ¹⁸F-FDG metabolism.In neoadjuvant chemotherapy of breast cancer,the pre-treatment SUVmax,ER,PR,Her2,Ki67,P53 receptor expression were not associated with pCR.But in locally advanced breast cancer patients,the pre-treatment MTV of primary cancer had significant prediction of pCR after neoadjuvant chemotherapy.In the postsurgical breast cancer patients,when compared with conventional imaging,PET/CT upstaged 4 patients（3.31%）,and downstaged 5 patients（4.17%）in restaging.In the prognosis analysis of PET/CT,compared with those with negative postsurgical ¹⁸F-FDG PET/CT findings,patients with the presence of ¹⁸F-FDG-avid tumor showed a significant decline of OS.It was found that compared with patients who proved negative in PET/CT examination,the relative Hazard Ratio（HR）of patients,for those pure lymphnode metastasis or local tumor recurrence,was 6.37,while that of the patients suffering from systematic metastasis was 16.00.For the¹⁸F-FDG avid patients,by ROC curve analysis,TLG cut-off value of 144.07,and MTV of 21.85 had the highest diagnostic value in the prediction of survival status in patients.TLG could predict overall survival in metastatic lung patients or those with lymph node metastasis of different area,but it had poor prognosis prediction in bone metastatic cases.【Conclusions】¹⁸F-FDG PET/CT had important role in monitoring metastasis and restaging postsurgical breast petients.The degree of ¹⁸F-FDG uptake of primary breast cancer correlated with Ki67 index,but it was not significantly relevant with ER,PR,Her-2 or P53 expression.The pre-treatment MTV of primary cancer in locally advanced breast cancer patients could predict pCR after neoadjuvant chemotherapy.Postsurgical PET/CT findings can provide strong prognostic value for the overall survival after PET examination.