Direct Molecular Analysis of In Vivo and Freshly Excised Tissues in Human Surgeries with the MasSpec Pen Technology

Intraoperative tissue analysis is critical to guide surgical procedures and improve patient outcomes. Here, we describe the clinical translation and intraoperative use of the MasSpec Pen technology for direct molecular analysis of in vivo and freshly excised tissues in the operating room. In this study, the MasSpec Pen was used by surgeons and surgical staff during 100 surgeries over a 12-month period, allowing rapid detection of rich mass spectral profiles from 715 in vivo and ex vivo analyses performed on thyroid, parathyroid, lymph node, breast, pancreatic, and bile duct tissues during parathyroidectomies, thyroidectomies, breast, and pancreatic neoplasia surgeries. The MasSpec Pen enabled gentle extraction and sensitive detection of various molecular species including small metabolites and lipids using a droplet of sterile water without causing apparent tissue damage. Notably, effective molecular analysis was achieved while no limitations to sequential histologic tissue analysis were identified and no device-related complications were reported for any of the patients. Collectively, this study shows that the MasSpec Pen system can be successfully incorporated into the operating room, allowing direct detection of rich molecular profiles from tissues with a seconds-long turnaround time that could be inform surgical and clinical decisions without disrupting tissue analysis workflows. ### Competing Interest Statement J.Z., R.J.D., J.Q.L., C.L.F., N.K., T.E.M., W.Y., J.S., and L.S.E. are inventors in US Patent No. 10,643,832 and/or in other patent applications related to the MasSpec Pen Technology licensed by the University of Texas to MS Pen Technologies, Inc. J.Z., T.E.M., J.S., and L.S.E. are shareholders in MS Pen Technologies, Inc. T.E.M., J.S., L.S.E., and C.L.F. serve as a technology adviser, chief medical officer, chief scientific officer, and a consultant, respectively, for MS Pen Technologies, Inc.. All other authors declare no competing interests. ### Funding Statement This work was supported by the National Cancer Institute of the National Institutes of Health under award numbers R00CA190783 and 1R33CA229068-01A1, and by the Gordon and Betty Moore Foundation through grant GBMF8049. The authors would like to thank all the patients in the study, the surgical technologists Stephanie R. Orenstein and Corey Jones Utley, and the clinical staff at the hospital affiliate of Baylor College of Medicine. The authors would also like to thank Tim Hooper for building the MasSpec Pen interface, and Noah Giese for assistance with laboratory experiments. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study was reviewed and approved by the Institutional Review Board (IRB) of Baylor College of Medicine and the IRB of the University of Texas at Austin All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Data will be available upon peer-reviewed publication of the manuscript.