Near-Infrared On-Site Evaluation (NOSE) Examination of EBUS/EUSb Samples—A New Method for Sample Adequacy Evaluation

Abstract

Fine-needle aspiration biopsy is crucial for modern diagnostics of endoscopic procedures and thus an efficient and reliable method for increasing biopsy yields is urgently needed. In our study, we address the limited availability and high price of the rapid onsite evaluation (ROSE) technique by introducing the technique of near-infrared on-site evaluation (NOSE) consisting of spectral measurement of near-infrared radiation (NIR) transmitted through the evaluated material. For this purpose, we designed a special optical probe consisting of two fibres, of which one is a source fibre and the second is a detector fibre. The distal ends of both fibres are brought together into one bundle which is, with the help of a special extension, applied to a cuvette with an analysed sample at a defined distance from the cuvette bottom and fixed in place. A portion of the NIR radiation received by the detector fibre after it propagates through the sample then depends on the optical and therefore morphological characteristics of the sample. Based on the measured spectral curve, we can calculate the attenuation coefficient curve and subsequently the parameter of the sample richness and the parameter characterising the autofluorescence peak as well. We found that the value of our introduced parameters is in significant relation to sample richness as well as to sample malignity. NOSE evaluation of EBUS/EUSb (endobronchial/oesophageal ultrasound bronchoscopy) specimens can be considered an easy new technique aiming to improve sampling diagnostic accuracy and to diminish costs related to the presence of a cytopathologist and related instrumentation in the endoscopy suite.