The goal of this study is to improve the unacceptably low diagnostic yield that is associated with low-risk bronchial biopsy. The investigators propose to do this by developing and optimizing a novel high-resolution optical coherence tomography (OCT) platform that will provide superior endomicroscopy images for biopsy guidance and in vivo diagnosis of lung cancer. OCT is a non-invasive imaging tool that rapidly generates high-resolution (\< 10 µm) cross-sectional images of biological tissues with penetration depths approaching 2-3 mm. Polarization Sensitive OCT (PS-OCT) provides additional contrast to structural OCT by highlighting birefringent tissues such as collagen. When coupled with appropriate catheter designs OCT can be used to conduct in vivo microscopy of tissue microstructure including the detection and diagnosis of cardiovascular, gastrointestinal, and lung pathology.
The objective of this study is to develop, test, and validate a clinically robust PS-OCT biopsy guidance and diagnosis platform that is compatible with standard bronchoscopy techniques. Specifically, the investigators envision two clinical scenarios:
Biopsy Guidance:
Following the identification and gross localization of a nodule by low-dose computed tomography (LDCT), a low-risk transbronchial biopsy will be acquired for diagnosis. Placement of the biopsy catheter will be performed using standard approaches including bronchoscopy, electromagnetic navigation, or robotic bronchoscopy. The investigators will then conduct PS-OCT at the site to (1) confirm that the biopsy catheter is correctly positioned within the nodule, and (2) ensure that diagnostic-quality tissue is obtained.
OCT Diagnosis:
For small isolated pulmonary nodules in vivo OCT imaging may open up the possibility of diagnosis and treatment within the same procedure. For larger pulmonary nodules OCT images of the tissue microstructure may also be used to provide complementary information to pathologists and treating physicians to help make a clinical diagnosis particularly when biopsy samples are inadequate. OCT can image a much larger volume of the tumor microenvironment than is possible with standard bronchial biopsy acquisition.
The advantages of this new platform over existing OCT technology include novel endobronchial catheters that include metalenses in their design. These catheters provide OCT images at significantly higher resolution over a greater depth of penetration than traditional OCT catheters. Our OCT platform will also incorporate cutting-edge polarization-sensitive OCT (PS-OCT) imaging capabilities which investigators have demonstrated are necessary to distinguish between tumor and non-diagnostic tissues including tumor-associated scar. PS-OCT is challenging to perform catheter-based imaging and extremely computationally expensive when it incorporates accurate catheter calibration and processing. Our endobronchial OCT imaging system will provide real-time intra-procedural processing which is critical for OCT biopsy guidance and diagnosis.
