NOSE examination of EBUS/EUSb samples- new method of sample adequacy evaluation

<bold>Introduction:</bold> Fine-needle aspiration biopsy is crucial for modern diagnostics in a wide range of endoscopic biopsy procedures. The methodology uses several optimization procedures to increase biopsy yields such MOSE – macroscopic onsite evaluation or the rapid on site evaluation- ROSE. We address limited availability and high price of ROSE technique by technique of NOSE (near infrared onsite evaluation). The technology is based on instant ex-vivo measurement of EBUS/EUS material by near- infrared spectroscopy. <bold>Methods:</bold> We use simple 2 fiber system adaptable to every cuvette used for evaluation. allowing NIR translumination and spectroscopy of analyzed sample. 60 EBUS procedures has been conveyed at one bronchoscopy center from 11/22 to 12/23. After every EBUS/EUSb pass the content of cuvette has been examined by NIR spectroscopy. Real time evaluation of spectroscopic curves allowed us to obtain information about sample density and cellularity/tumorous content- <bold>Results:</bold> We selected main criteria defining sample quality. a) the ratio between maximal absorbance to maximum absorption of blood and water in the interval 638-900 nm and b) maximum peak of auto fluorescence signal at 698-719 nm. The resulting combined arbitrary value of more then 2.5 is predictive for high quality sample and achieving that value resulted in 98% diagnostic yield by histology /cytosediment evaluation. <bold>Discussion:</bold> NOSE evaluation of EBUS/EUSb specimen is a new easy technique aiming to improve the sampling diagnostic accuracy and to diminish costs related to the presence of a cytopathologist and its instrumentation in the endoscopy suite. Our results show good clinical applicability.