in vivo Cancer Detection
Diffuse optical methods based on near-infrared light illumination have a great potential for detection and therapy monitoring of disease by providing information on several unique deep tissue functional/metabolic parameters. With diffuse optical spectroscopy and tomography (DOS & DOT), oxygenated hemoglobin, deoxygenated hemoglobin, water and lipid concentrations, and tissue scattering properties can be reconstructed. With diffuse correlation spectroscopy (DCS), blood flow information is accessible optically. DOT, DOS and DCS are non-invasive methods that are based on surface measurements.
On the other hand with minimal invasion, tissue micro-environment (e.g. vascular leakiness) or selective uptake of molecular targeted agent in the diseased tissue can be probed by measuring fluorescence signal of exogenous optical contrast agents. In addition to these unique functional parameters, diffuse optics utilize non-ionizing radiation (thus enabling frequent measurement), and low cost instrumentation. These features make diffuse optics suitable for providing complementary information to traditional clinical imaging modalities (e.g. X-ray, Ultrasound, MRI, PET/SPECT), and for monitoring progression or therapeutic response of a disease.
Near-infrared light focused on a turbid medium with similar optical properties to tissue goes through multiple scattering events. Diffuse optical techniques quantify optical properties based on photon diffusion equation for modeling photon propagation in tissue-like turbid medium. From the optical properties, one can extract physiological/metabolic information such as total hemoglobin concentration, blood oxygen saturation, and blood flow.
In our laboratory, we assess and improve the capabilities of diffuse optics in breast cancer detection, diagnosis and therapy monitoring. In clinical measurements of human breasts with tumor, we focus on identifying functional parameters which can serve as early indicators of therapy efficacy. Using a preclinical animal model, we study the metabolic mechanism of varied responses to therapy seen in the clinic, and investigate new therapeutic drugs and interventions. Also, we explore new functional and metabolic parameters (e.g. glucose metabolism) accessible through near-infrared fluorescent optical agents. In the near future, we plan to expand our research to different cancers (e.g. head & neck tumor, lymphoma) and to different organs (e.g. brain).
- Blood flow reduction in breast tissue due to mammographic compression. Acad Radiol. 21, 151-61. (2014 Feb 01).
- Optically measured microvascular blood flow contrast of malignant breast tumors. PLoS One. 9, e99683. (2014 Jan 01).