Table 6 Optical biopsy
Optical biopsy | Technology | Light source | Information provided | Sensitivity % | Specificity % |
|---|---|---|---|---|---|
Auto-fluorescence spectroscopy | Fluorochromes fluorescence (NAD, FADH) | ultraviolet and visible spectrum light | Distinguish malignant tissue by concentration of (NAD, FADH), re-emit green light | 81 | 100 |
Enhanced dye fluorescence | Fluorochromes fluorescence (protoporphyrin IX) | ultraviolet and visible spectrum light | Distinguish malignant tissue by high concentration of (protoporphyrin IX), re-emit red light | 100 | 100 |
Ratio imaging | fluorescence (protoporphyrin IX, NAD, FADH) | ultraviolet and visible blue light | Compare a ratio of red emission of (protoporphyrin IX) from malignant cells with the green emission from normal | from 60 to 97 | from 75 to 99% |
Raman spectroscopy | Raman vibrational spectroscopy | laser-based spectroscopic technique | enabling chemical characterization | 80.5 | 86.2 |
Elastic scattering spectroscopy | Elastic scattering (white light reflectance) | pulsed xenon arc lamp | provides optical geometrical information | 92 | 79 |
Differential path-length spectroscopy | Elastic scattering (white light reflectance) | tungsten-halogen lamp | cell biochemistry, intracellular morphology and microvascular properties such as oxygen saturation and average vessel diameter | 69 | 85 |
Optical Coherence Tomography | scattered light (Fourier domain mode lock swept source-based) OCT | laser-based | Provide provide high-speed three-dimensional OCT pictures | Subjective image required interpretation | Subjective image required interpretation |
Angle-resolved low coherence interferometry (A/LCI) | scattered light to measure the average size of different cell structures | laser-based | delivers direct confirmation of precancerous disease to the physician | 100 | 85 |