Wavelength-modulated Differential Photoacoustic Spectroscopy for Early Detection of Breast Cancer and Hypoxia Monitoring

In the field of medical diagnostics, biomedical photoacoustic (PA) imaging is a non-invasive hybrid optical-ultrasonic imaging modality. Due to the unique hybrid capability of optical and acoustic imaging, PA imaging has risen to the frontiers of medical diagnostic procedures such as human breast cancer detection. The current study introduces a novel PA spectroscopic modality for ultra-sensitive characterization of functional information for breast cancer imaging. Wavelength-modulated differential Photoacoustic spectroscopy (WM-DPAS) detection has been developed to address angiogenesis and hypoxia monitoring, two well-known benchmarks of breast tumor formation. Based on the WM-DPAS theory, this modality efficiently suppresses background absorptions while amplifying the small PA signal, thereby optically identifying pre-malignant tumors before they are anatomically apparent. The potential of the WM-DPAS to sensitively detect human breast pre-malignancy and quantify the corresponding breast carcinogenesis benchmarks was studied using an in-vitro blood circulation system. The experimental results were compared to the developed theoretical formalism.M.A.S