Applications of quantitative phase imaging for pathology

Abstract

Prostate cancers, which account for 14% of all cancers diagnosed in the United States, and colorectal cancers, which account for 8.2% of all cancers, present a unique set of diagnostic problems [1]. In the case of prostate cancer, overdiagnosis of early-stage disease and poor accuracy at characterizing high-risk disease, especially when diagnosed at the intermediate stage, are major problems. A new prognostic method is thus necessary for improving prostate cancer management. In the case of colorectal cancer, early disease diagnosis is of critical importance for the purpose of reduction in disease-specific death rates. An automated screening tool which identifies cases that warrant further examination by the pathologist would assist in the implementation of a wide-spread screening program. Quantitative phase imaging (QPI) of unstained tissue provides information on the refractive index distribution, or tissue morphology, with nanometer level sensitivity. Subtle morphological changes in both the epithelial and stromal regions of tissue, which are not visible in stained tissue sections used in current pathological settings, can be measured using QPI. Thus QPI would be a valuable addition to current diagnostic pathology.