Smartphone spectroscopy for melanoma detection

Rates of melanoma mortality are greater in remote areas than in cities. In the United States early-stage melanoma incidence was slightly higher in cities while later stage incidence with metastatic spread was higher in rural areas, suggesting a diagnosis gap between the two. Early detection is key as the 5-year survival rate with early discovery can reach 99%, but as the cancer spreads this survival rate is reduced to 27%. This problem is exacerbated by the inaccessibility of state-of-the-art medical care in remote areas. Thus, an affordable, easily operated, tool can help close the diagnostic gap. Previous studies show melanoma’s reflective and fluorescent spectral signature to be distinct from that of healthy skin, which can be utilized for in-vivo skin cancer detection. Here we present a smartphone spectroscopy system as a tool for melanoma screening with the aim of bringing point-of-care testing to remote areas. The spectrometer consists of a fiber optic cable, collimator, and diffraction grating which couple directly to the smartphone camera, detecting a spectrum in the range of 380-650nm. The spectral data is analyzed and displayed by a custom developed phone application, which uses the smartphone’s integrated computing to extract and calibrate the spectrum. Key spectral features tied to melanoma can then be input into a classification model, with the aim of providing a noninvasive rapid optical biopsy. The results are promising; preliminary validation of the system is conducted; next steps include collection of a robust training data set of skin samples.