Measurement of hypoxia-related parameters in bronchial mucosa by use of optical spectroscopy

Rationale: Tumor hypoxia has both prognostic and therapeutic consequences for solid tumors. We developed a novel noninvasive technique, differential path-length spectroscopy (DPS), which allows the measurement of hypoxia-related parameters in the superficial microvasculature of tissue. Objectives: The aim of this study was to measure the microvascular oxygenation of histologically normal endobronchial mucosa and of neoplastic lesions during bronchoscopy using DPS. Methods: Sixty-four patients with known or suspected malignancies of the lung were studied. One hundred and five endobronchial lesions (38 histologically normal, 37 metaplastic/ mild dysplastic lesions, and 30 invasive carcinomas) were detected by white and/or autofluorescence bronchoscopy and measured using DPS. Results: We observed that bronchial tumors are characterized by a lower blood oxygen saturation and a higher blood content than normal mucosa. No differences were observed between normal and metaplastic/mild dysplastic mucosa. Conclusion: DPS is a new optical technique allowing the noninvasive study of endobronchial tumor hypoxia.