Potential assessment of lung samples by X-ray histology (XRH) during surgery

More than 25,000 operations to remove all or part of a patient’s lung take place in Europe each year. The full extent and type of changes in lung structure due to disease may not be evident until surgery is underway. Immediate microanatomical assessment of removed tissue can guide and inform the surgical team. We explored the feasibility of using micro-computed tomography (µCT) based X-ray histology (XRH) for timely 3D histological imaging during surgery. Key criteria include (1) visualisation of relevant microanatomical structures (2) results in less than 20 minutes during the operation (3) rapid and effective presentation of the data-rich 3D images and (4) compatibility with current intra-operative and post-operative pathology protocols. For protocol development, pig lung was used as it is similar in size and structure to human lung. Using optimised µCT scan conditions at our XRH facility in Southampton, consistent 3D imaging of fresh, unfixed peripheral lung samples was demonstrated (n=6), providing relevant microanatomical information in less than 10 minutes (Fig 1). Snap freezing and/or air-inflation of lung samples were also feasible within the time required. Both required additional preparation steps and could lead to over-inflation or affect preparation for routine wax histology, respectively. Short scan times minimised the impact of sample movement on image quality. A system for rapid, automated generation of user-friendly reports was developed. This brings together images and sample details for assessment, patient records and clinical team discussions. To streamline the integration of XRH with existing protocols, we scanned samples in standard containers used to transfer surgical samples to the pathology lab. This allows fast, non-invasive, non-contact scanning in a sealed container, reducing sample handling and avoiding contamination. The rapid XRH data were judged to be of potential diagnostic quality by pathologists. This approach provides opportunities for future research and diagnostic use.