MRI Evaluation Of Residual Tumor After Neoadjuvant Chemotherapy: A Preliminary Study

Breast cancer is a significant threat to women health care.Neoadjuvant chemotherapy(NCT)has been the standard treatment for women with breast cancer,and it is well recognized that NCT could increase the likelihood of breast-conserving surgery(BCS)by reducing the tumor size and downstaging tumor.BCS has gained increasing acceptance as a treatment option for breast cancers considering the facts that the overall survival and disease free survival for patients receiving BCS equals to those with mastectomy,and BCS could maintain the breast shape and increase the patient's life quality.However,not all breast cancer patients in this setting are suitable to BCS after NCT,because sometimes tumor shrinkage is uneven and viable foci may remain in some distance from the central residual tumor site,which would result in positive margins and residual cancer if BCS is performed.Therefore,it is important to obtain the precise tumor shrinkage patterns after NCT when deciding whether the patient is suitable for BCS.In the present study,we evaluate the ability of magnetic resonance imaging(MRI)in assessing the tumor shrinkagepattern following NCT by comparing the findings from pathological whole subserial section(WSS).1.Agreement between MRI and whole subserial section in assessing tumor shrinkage patterns after neoadjuvant chemotherapy for breast cancer patientsObjective: To evaluate the ability of breast MRI in assessing the tumor shrinkage pattern following NCT.Methods: 35 patients with clinical TNM stage ?and stage ? infiltrating duct carcinoma were enrolled in this study,who achieved partial response(PR)after neoadjuvant chemotherapy with Taxol and Epirubicin(TE).All patients had two separate MRI examinations: one examination prior to NCT and the other examination after completion of chemotherapy.35 patients received modified radical mastectomy after NCT,and the samples were subjected to perform WSS.Pathological changes of tumor bed and pericancerous tissues were examined with optical microscope.Results: The shrinkage patterns were divided into two types,concentric shrinkage(CS)and dendritic shrinkage(DS).According to shrinkage pattern assessed by MRI,a total of 28(80.00%)patients showed CS after NCT,while,7(20.00%)patients showed DS.The WSS shrinkage pattern was CS in 29(82.86%)patients after NCT,and DS in 6(17.14%)patients.Twenty-eight(80.00%)and 6(17.14%)patients showed CS and DS both in MRI and WSS after NCT,respectively,and thecorrelation coefficient between the tumor shrinkage patterns assessed by MRI and thatdetermined by pathological whole subserial section after NCT was 0.906(P = 7.37×10?8).Conclusions: There were two shrinkage patterns of residual breast cancer after neoadjuvant chemotherapy: concentric shrinkage(CS)and dendritic shrinkage(DS).There exists high agreement between MRI and WSS in assessing tumor shrinkage patterns after NCT for breast cancer patients.MRI could be useful in determining residual disease after completing NCT.2.The application of breast MRI in neoadjuvant chemotherapyObjective: To explore the correlation of breast MRI and tumor shrinkage shrinkage.Methods: Analyzing the MRI data of breast cancer both before and after neoadjuvant chemotherapy,and studying the relationship between the tumorlongest diameter,the dynamicvariables,apparent diffusion coefficient(ADC)value and residual tumor shrinkage patterns.Results:There were significant associations between the primary tumor longest diameterassessed by MRI and tumor shrinkage patterns(P < 0.001).Tumor shrinkage patternswere not significant with time-signal intensity curve(P>0.05);Tumor shrinkage patterns by MRI were not significantly related to SIpeak?Tpeak?ECU(P>0.05);The correlation coefficient between the ratio of tumor shrinkage and the ADC value before NCT was R=-0.775(P<0.001),but the ADC values were not significant with tumor shrinkage patterns assessed by MRI(P>0.05)Conclusions:There were statistical significance in tumor shrinkage patterns and the primary tumor longest diameter,and dendritic shrinkage was easy to find in larger primary tumor.The ADC values before neoadjuvant chemotherapy were negatively correlated with the ratio of tumor shrinkage,but were not significant with tumor shrinkage patterns.