Investigation of multiphoton microscopy as an innovative tool for intraoperative section-free histologic investigations in just a few minutes

BackgroundMultiphoton microscopy is an innovative procedure that enables the histological examination of tissue samples without the prior production of thin sections using paraffin or freeze preparation. As a result, time-critical examinations in the operating room can be considerably simplified and accelerated. As part of the study, a mobile tissue scanner will be analyzed using resection tissue from multiple surgery departments. The image quality, the staining protocols and the laser parameters will be analyzed.MethodsMultiphoton microscopy uses a laser source to specifically utilize a non-linear optical effect in order to scan individual depth levels in tissue blocks. The tissue only needs to be briefly immersed in dye to obtain H&E images that are directly available in digital format. The planned sample size of the study includes 400 samples from neurosurgery, general surgery, gynecology, urology and dermatology. Both healthy and diseased samples are analyzed. Depending on the department, the resections are either directly transported from the operating room to our lab in a nutrient solution or are first sent to the pathology department for examination, where a pathologist decides which tissue can be used for the study.ResultsThe study has provided the first promising images from various tumor types such as melanoma, colon cancer and an infiltrating malignant tumor in uterus tissue. The staining protocol is now much more reliable and usually takes 2:30 min. The multiphoton microscope achieves a scanning speed of 4 min/cm2, with a further acceleration potential to 30 s/cm2. The image quality is better than that of frozen sections and shows no artefacts due to freezing or cutting (e.g. cracks & folds).ConclusionsIn initial trials with resection tissue, multiphoton microscopy has proven to be a reliable and fast measurement method that could enable H&E imaging of tissue in less than 10 minutes. In the later stage of our study, the images will be compared directly with the intraoperative frozen sections and the microscope will also be tested directly in the operating room and the pathology department. We also plan to increase the imaging speed to reach the full potential of our imaging modality.Editorial acknowledgementDuring the preparation of this work the author(s) used www.deepl.com in order to translate some of the text. After using this tool/service, the author(s) reviewed and edited the content as needed and take(s) full responsibility for the content of the publication.Legal entity responsible for the studyHistolution GmbH.FundingHistolution GmbH.DisclosureM. Homs Soler: Financial Interests, Personal, Stocks/Shares, Shareholder: Histolution GmbH. All other authors have declared no conflicts of interest.