Enhancing Nodule Biopsy Through Technology Integration

by Janani Reisenauer, M.D

Lung cancer was the leading cause of cancer-related death in 2020. Nearly half of those patients diagnosed were found to be late-stage, meaning after the cancer had spread to distant sites in the body, which is correlated with poor survival. There has been ongoing work to increase screening for lung cancer in at-risk patients with enhanced imaging. However, after identification of suspicious nodules or masses, there remains the task of diagnosing any cancerous lesions. Unfortunately, obtaining accurate biopsy results has been a challenge either due to inaccurate results from conventional bronchoscopy, or risk from alternative mechanisms of biopsy.

Limitations of Bronchoscopy in Sampling Lung Nodules

Bronchoscopy, a procedure where the operator navigates through the patient’s airways using a camera at the end of a flexible tube, has been one of the major techniques for sampling lung tissue for nearly 50 years. However, the success rate of bronchoscopy for navigating to the periphery of the lung has been underwhelming. Even with the introduction of “navigational” bronchoscopy, where electromagnetic systems are used to track where the bronchoscope is within the airways, the diagnostic yield has been estimated to be in the 67-84 % range. During many cases, it was observed the apparent location of the nodule had changed compared to the CT scan used for planning the route to the target. This is likely due to patients taking full inspiratory breaths, inflating the lungs as much as they can, at the time of imaging. However, during the procedure, the patients breathe at lower lung volumes, closer to those one would see at rest or light activity. The location of the target nodule between these lung volumes can differ by an average of 2 cm in the lower lobes, a distance often larger than the size of the nodule itself.

Integration of Mobile Computed Tomography (CT) with Navigational Bronchoscopy

With the high likelihood of change in location between planning images and the procedure itself, use of mobile CT imaging systems allows the operator to examine where the biopsy tool is in relation to the target. This is done once the operator has navigated to where nodule was located on the initial imaging and allows visual confirmation of the biopsy tool inside the lesion of interest before multiple samples are taken.

A study evaluating 30 patients using these integrated technologies was able to show the biopsy tool in the lesion of interest in all cases, and a diagnostic yield of 93.3%. Compared to traditional bronchoscopy techniques, this reflects a significant improvement. The diagnostic accuracy approaches that of CT-guided biopsy, a procedure where a needle is directed from the outside of the patient, through the chest wall under CT imaging guidance to help direct the trajectory and confirm the needle is in the target. However, CT-guided needle biopsy carries roughly a 37% risk of introducing a pneumothorax, or air leak, around the lung, with a chest tube required in 12% of cases. No cases of pneumothorax were noted in the initial series of robotic-assisted bronchoscopy.

A limitation of this technology is the high initial cost of both navigational systems as well as the portable cone-beam unit, making this service not available in all centers. However, with increased screening and nodule discovery, it is worth considering if this higher diagnostic accuracy may have an overall net cost benefit for patients. Whether this benefit would apply to all patients or only those with small and/or peripheral nodules is currently not known. With time and growing experience, it is expected that procedural times and the number of tool manipulations, and CT images obtained will likely all decrease, increasing procedural efficiency as well.

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Article Details
Enhancing Nodule Biopsy Through Technology Integration
Jennifer D. Duke, MD, David Sanborn, MD, Janani Reisenauer, MD
First Published February 18, 2023 Research Article
DOI: 10.1177/15569845231153639
Innovations: Technology and Techniques in Cardiothoracic and Vascular Surgery

About the Author

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Janani Reisenauer, M.D., is the Division Chair of Thoracic Surgery at Mayo Clinic in Rochester, Minnesota. She has been with Mayo Clinic since finishing her fellowship at the Mayo Clinic School of Graduate Medical Education in 2018. Dr. Reisenauer was the world’s first dual fellowship trained and board-certified interventional pulmonologist and thoracic surgeon and remains one of very few people to achieve both certifications. She earned both her bachelor’s degree and Doctor of Medicine degree at the University of Alabama in Birmingham, Alabama and she completed her residency and both fellowships at Mayo Clinic School of Graduate Medical Education in Rochester, Minnesota. Dr. Reisenauer and her team specialize in robotic bronchoscopy, a minimally invasive technique that allows her to detect lung cancers with more accuracy than traditional bronchoscopy. Earlier detection allows people to begin treatment sooner and leads to better results. She is currently involved in clinical trials that deliver breakthrough cancer treatment through the bronchoscope or with surgery within minutes of diagnosis. If successful, these techniques could help people receive life-saving care sooner than ever. Dr. Reisenauer is passionate about making care easier and more accessible for everyone. She hopes to help those in under-resourced communities through telehealth, collaborating with physicians, and using more efficient tools like the bronchoscope. Dr. Reisenauer’s drive to innovate extends beyond the surgical suite. As Director of the Innovation Center for the Department of Surgery at Mayo Clinic, she leads the annual Beahrs Surgical Innovation Summit, where Mayo Clinic doctors and medtech startups work toward advancing the future of surgical care, together.