Association Studies On Assessing Tumor Infiltrating Lymphocytes In The Immune Microenvironment Of Breast Cancer Based On Multiparametric Magnetic Resonance Imaging

Breast cancer is the highest cancer in the world with the highest incidence and high fatality rate.Tumor infiltrating lymphocytes(TILs)in the tumor immune microenvironment(TIME)have been found to be an important biological indicator as the interaction between tumor and immune microenvironment has been further studied.It has been proven to be an independent prognostic indicator for breast cancer,which can help us understand the immune status of the tumor,predict prognosis,guide individualized immunotherapy,and monitor response.However,quantitative assessment of TILs levels in tumors has drawbacks such as being invasive,time consuming,and unable to be performed multiple times,and its clinical application is limited.Non-invasive assessment of TILs based on imaging provides a new opportunity to solve this problem.In recent years,visual magnetic resonance imaging based on morphological observation has been gradually transformed to high-throughput quantitative feature analysis and quantitative multifunctional magnetic resonance imaging.The MRI multi-parameter analysis can be used to diagnose,differentiate,predict and evaluate the curative effect of the disease,which is of great significance in assisting clinical decision making.The main research contents of this paper include:(1)Diffusion kurtosis imaging(DKI)and dynamic contrast-enhanced(DCE)scanning were used in our study due to the lack of current studies on the correlation between functional magnetic resonance imaging(MRI)and TIL level in breast cancer.Using multiple parameters derived from multifunctional MRI,the relationship between the multiple parameters and TIL levels in tumor immune microenvironment of mouse breast cancer was preliminarily explored.The results showed that there was a certain correlation between the MK values in DKI and the TILs levels of mice breast cancer,and there was an indirect correlation between the Ktrans and Ve values in DCE scanning and the TILs levels of mice breast cancer.In this study,we preliminarily explored the use of functional MRI to evaluate TILs in mice with breast cancer,and suggested a potential association between functional MRI and TIL levels in breast cancer.(2)Based on the previous chapter content suggest there is the potential relationship between the ADC value of functional MRI parameters and TIL levels in mouse breast cancer,this research adopts the whole ADC histogram of human breast cancer lesions to evaluate preoperative TIL level,and further explore the possible relationship between ADC quantitative indicators in different molecular subtypes of breast cancer and TIL levels.It was found that 10^thand 25^th percentile ADC values were of great value in the assessment of different TILs in breast cancer.The 10^th percentile ADC value and kurtosis were used to evaluate the TILs of luminal and non-luminal breast cancers,respectively.This study demonstrates an association between functional MRI and TIL levels in human breast cancer.(3)Based on the research results in the previous chapters,the radiomics method was used to explore the extraction of multiple features from MRI,and to mine more potential information related to human breast cancer TIL levels through bioinformatics method.It was found that in the multi-phase of DCE-MRI,the predictive ability of enhanced delayed phase was better.In this study,we optimized the selection of the phase of DCE-MRI for TILs predicting in the radiomics studies,and demonstrated the importance of MRI-based combined radiomics features in the prediction model.In conclusion,this study used functional MRI to evaluate the TIL levels in mice with breast cancer.On this basis,functional MRI parameter ADC histogram analysis and MRI-based radiomics were used to predict the TIL levels in human breast cancer.