Elemental Imaging And Cluster Analysis Of Breast Cancer Tissues Using Laser-induced Breakdown Spectroscopy

Breast cancer has been and will continually be one of the major fatality rates in malignancy cancer in the long term.The elements distribution in breast cancer tissue can help to expand the information dimension of pathologists,to establish a recognition and diagnosis model of breast cancer.It will be greatly important to improve the accuracy of pathological diagnosis.Laser-induced breakdown spectroscopy(LIBS)is an advanced technology to realize the synchronization,fast and on-line measurement of multiple elements,which has been a wide application prospect in biological tissue elements analyses.This work presents first-of-its-kind LIBS measurements and correlative explorations of the elemental imaging in breast cancer tissue to our knowledge.Based on LIBS,this paper study elemental imaging and cluster analysis(CA)in the breast cancer tissue.Firstly,the application and background of cancer diagnosis and biological tissue imaging with LIBS are introduced,and the shortcomings of breast cancer tissue imaging,especially CA,are discussed.And then the physical mechanism of LIBS,principal component analysis,CA and model accuracy determination are briefly illustrated.Secondly,a LIBS imaging system for ultrathin section of biological tissues is established,in which the parameters of focusing parameters,scanning step size,atmosphere gas,detection delay selection are further optimized,so we can obtain LIBS spectra of breast cancer with ductal carcinoma and lobular carcinoma,establish spectral pictures containing K,Ca,Na,Mg,and analyze the correlation between elements distribution and group tissues(cancer cells,healthy tissue,necrotic cells,etc.).The results show that,the elements distribution of K,Ca,Na,and Mg between precancer cells and healthy cells is little difference in ductal carcinoma and lobular carcinoma.The concentration of Ca and Mg elements in malignancy cells is higher than that in healthy cells,and the distribution of K and Na elements has no specific rules for invasive ductal carcinoma and invasive lobular carcinoma.The elements of malignancy groups containing necrotic tissue are not evenly distributed,while the spectral intensity of necrotic tissue elements decreased with the deepening of nuclear dissolution.Finally,based on the LIBS spectral of malignancy groups,the model of cancer recognition and diagnosis is established by optimizing principal component combination and distance function for CA model,which can also realize the visualization of cancer cells.The CA method,which the highest accuracy,sensitivity and specificity were 72.28%,72.23%,and 80.99%,respectively,can be evaluated through the registration of elemental images with LIBS and stained images with cancer cells and healthy cells in medical diagnosis.The correlation coefficients between CA results and elements distribution of K,Na,Mg and Ca are generally higher than 0.6,0.6,0.7 and 0.75,respectively,which strongly illustrate the important role of the alkalis elements in CA method,especially Ca.We expect that the results can provide a basis and reference for relevant investigations on LIBS biological tissue elemental imaging and disease diagnosis.