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.