Intravital Microscopy (IVM) in Human Solid Tumors: Novel Protocol to Examine Tumor-Associated Vessels

Abstract

Background Intravital microscopy (IVM) allows the real-time, direct visualization of microscopic blood vessels. This pilot clinical trial will elucidate the physical and functional characteristics of vessels associated with solid tumors. Objective The main objective of this study is to determine the feasibility of performing IVM in patients with solid tumors during the standard course of surgical resection. IVM will also be performed when vasopressors or fluid boluses are administered during the standard course of the operation. Methods This is an open-label, nonrandomized, single-center, pilot study of IVM observation in subjects with solid tumors undergoing surgical resection. Results This study was active on January 1, 2019 (NCT03823144) and funded by the Mayo Clinic Florida Cancer Focused Research Team Award. As of September 27, 2020, we had enrolled 20 patients. Accrual period is expected to end by December 31, 2021. Conclusions This trial will support the development of interventions to improve patient treatment by extending the application of IVM to the tumor microenvironment. IVM observations during volume and pressor management at the time of surgery may aid in the development of strategies to augment responses to systemic treatments. International Registered Report Identifier (IRRID) PRR1-10.2196/15677

Human intravital microscopy in the study of sarcomas: an early trial of feasibility

“…Patients were enrolled in single center, nonrandomized clinical trials at Mayo Clinic in Jacksonville, Florida, USA. These trials included Intravital Microscopy (IVM) in Patients with Peritoneal Carcinomatosis (ClinicalTrials.gov identifier: NCT03517852) and Intravital Microscopy in Human Solid Tumors (ClinicalTrials.gov identifier: NCT03823144) ( 6 , 8 ). Both trials received IRB approval from the Mayo Clinic (IRB #17-009823 and IRB #18-010370, respectively).…”

“…Both trials received IRB approval from the Mayo Clinic (IRB #17-009823 and IRB #18-010370, respectively). The protocols for these trials, and the inclusion and exclusion criteria had previously been reported and are available through nct.gov ( 6 , 8 ). Briefly, patients underwent informed consent for participation and received a fluorescein skin prick test to evaluate the low risk of an allergic reaction to the fluorescein dye used to enhance the intravital in-human observations of blood vessels.…”

“…The technique for real-time human intravital microscopy had also been previously described by our group ( 6 , 8 ). Briefly, we utilized the ultra-high definition (UHD) probe-based confocal laser endomicroscopy device (Gastroflex, Cellvizio System, Mauna Kea Technologies, Paris, France).…”