Two blinded studies testing the effectiveness of using in vivo confocal microscopy machines by Lucid, a Rochester, New York firm, have produced positive results for detecting melanoma.
The study, lead by Dr. Giovanni Pellacani, contained a total of 351 equivocal melanocytic lesions that were difficult for expert dermoscopists to diagnose. 136 of the 351 lesions were malignant melanomas. The highest sensitivity demonstrated by confocal microscopy was 96.3%. The highest accuracy corresponded to a sensitivity of 91.9% and a specificity of 69.3%. The standard of comparison for the study was biopsy of all 351 lesions,
followed by traditional pathological examination.
“By giving reliable diagnostic information comparable to histology, confocal imaging represents the only feasible alternative to biopsy in the decision-making process faced by dermatologists examining melanocytic lesions,” said Dr. Giovanni Pellacani, Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy, one of the world’s leading in-vivo confocal imaging medical researchers. “Consequently, in vivo confocal microscopy is used at Modena and in several other melanoma clinics in Europe for the analysis of melanocytic lesions,” Dr. Pellacani continued.
Lucid provides details about the technology:
Using advanced laser technology, VivaScope imagers can produce optical images of skin lesions with incredible cellular resolution, enabling medical professionals to see cellular morphology — in real time, in living tissue…
The images produced by confocal microscopy have similar resolution to images used by pathologists in diagnosing disease…
In operation, a virtual point source of light, derived from a laser, passes through beam-shaping optics into a beamsplitter. The beamsplitter reflects the laser beam to a scanning optics assembly that scans the beam in two orthogonal directions. The scanned beam is next directed toward the entrance pupil of an objective lens that focuses the beam to a point within the sample. Due to either natural index of refraction variations or fluorescence in the tissue, a portion of the light at the focal point propagates back toward the objective lens and is collected. This returning collected light passes back through the system and the beamsplitter to be imaged via a pinhole aperture preceding the photodetector. The pinhole aperture is matched in size to the illuminated spot. As a result, the detector receives light only from a thin, in-focus plane in the sample. Light from out-of-focus planes is rejected at the pinhole. The point source of light, the illuminated spot in the sample, and the pinhole aperture lie in optically conjugate focal planes – hence the name “confocal.”