Intravital Microscopy in Human Solid Tumors

May 29, 2026 updated by: Mayo Clinic

Intravital Microscopy (IVM) in Human Solid Tumors

This study will investigate the tumor-associated vasculature of patients with solid tumors. The investigators will use a technology known as intravital microscopy (IVM) in order to visualize in real-time the vessels associated with solid tumors. The IVM observations may determine if an individual patient's tumor vessels would be amenable to receiving systemic therapy, based on the functionality of the vessels.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

PRIMARY OBJECTIVE:

I. To determine the feasibility of performing human intravital microscopy (HIVM) in patients with deep space solid tumors during standard course of surgical resection.

SECONDARY OBJECTIVES:

I. Compare the microscopic observation of the tumor-associated vessels with normal tissue (e.g. peritoneal surface or normal brain tissue) in each individual subject.

II. Correlate the microscopic observations of the tumor-associated vessels with pathologic grade of tumor.

III. To correlate the microscopic observation of the microvasculature with tumor-specific and overall survival.

OUTLINE:

Patients receive fluorescein intravenously (IV) and undergo HIVM over 1-2 minutes per field.

After completion of study, patients are followed up at 2-3 weeks after surgery.

Study Type

Interventional

Enrollment (Estimated)

85

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United States
    • Florida
      • Jacksonville, Florida, United States, 32224
        • Recruiting
        • Mayo Clinic Florida
        • Contact:
        • Principal Investigator:
          • Emmanuel M Gabriel, M.D., Ph. D.
        • Sub-Investigator:
          • Michael B Wallace, M.D.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age ≥ 18 years of age
  • Eastern Cooperative Oncology Group (ECOG)Performance Status of ≤ 2
  • Measurable tumor by direct visualization requiring surgical resection in the operating room (OR)
  • Tumor types of origin include gastric, pancreatic, hepatobiliary, colorectal, sarcoma, brain, or breast cancer that may involve the axillary lymph nodes cancers. Tumors may be primary or metastatic
  • Subject must understand the investigational nature of this study and sign an Independent Ethics Committee/Institutional Review Board approved written informed consent
  • Subject must have a skin prick test pre-operatively (at the time of the preoperative visit and after signed informed consent for entry into this clinical trial is given) to determine any sensitivity to fluorescein

Exclusion Criteria:

  • Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations
  • Renal dysfunction as defined as a glomerular filtration rate (GFR) < 45
  • Liver dysfunction as defined by Child-Pugh score > 5, or liver function test (LFT)'s 1.5 x above normal range
  • Any known allergy or prior reaction to fluorescein or a positive skin prick test to fluorescein
  • Pregnant or nursing female subjects, determined preoperatively with a urine pregnancy test
  • Unwilling or unable to follow protocol requirements
  • Any condition which in the investigators' opinion deems the patient unsuitable (e.g., abnormal electrocardiography [EKG], including T wave inversion, elevated T waves, prolonged QRS interval, or conduction blocks) or that requires further work-up (including cardiac echo or stress test)
  • Any condition that excludes surgical resection as the standard of care for the patient

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Arm 1
Determine the feasibility and clinical utility of performing Human Intravital Microscopy (HIVM) in patients with solid tumors during surgical resection.
Device: Diagnostic Microscopy
Undergo Intravital microscopy (IVM), which allows real-time, direct visualization of microscopic blood vessels and calculation of blood flow.
Other Names:
  • IVM
  • Human Intravital Microscopy
  • HIVM
Drug: Fluorescein Sodium Injection
Given IV as part of IVM procedure
Other Names:
  • AK-Fluor
  • Fluorescite

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
1. Tumor vessel identification (# tumor vessels visualized per high power field)
Time Frame: 12-15 minutes
Identify and measure vessels associated with solid tumors
12-15 minutes
2. Tumor vessel density (# tumor vessels per square cm area observed)
Time Frame: 12-15 minutes
Determine vessel density per 10x field
12-15 minutes
3. Fluorescent dye uptake (# tumor vessels with fluorescent dye uptake and # tumor vessels without dye uptake)
Time Frame: 12-15 minutes
Visualize vital dye within the vessels (fluorescein)
12-15 minutes
4. Tumor blood flow (velocity, mm/sec)
Time Frame: 12-15 minutes
Calculate the blood flow velocity of the vessels and tissue penetration of fluorescent dye as a marker of vessel permeability.
12-15 minutes

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Post-operative correlation of the microscopic observation of the tumor microvasculature tumor-specific and overall survival.
Time Frame: 5 years
The investigators will determine if there is a correlation between the microscopic observation of the tumor microvasculature tumor-specific and overall survival.
5 years
5. Post-operative comparison of the microvasculature of tumor with normal tissue
Time Frame: 15-20 minutes
Post-operative comparison of the microvasculature of tumor with normal tissue (e.g. peritoneum) in each individual subject using vessel diameters, vessel density, detection of intravital dye and flow rates.
15-20 minutes
6. Post-operative correlation of the microvasculature with pathologic features of the tumor implants (i.e. tumor grade) at the time of the final pathology report (5-7 days after surgery).
Time Frame: 5-7 days
The investigators will determine if there is a correlation between the microvasculature with pathologic features of the tumor implants (i.e. tumor grade) at the time of the final pathology report (5-7 days after surgery).
5-7 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Mayo Clinic

Investigators

  • Principal Investigator: Emmanuel M Gabriel, M.D., Ph.D., Mayo Clinic

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 28, 2019

Primary Completion (Estimated)

September 30, 2027

Study Completion (Estimated)

September 30, 2027

Study Registration Dates

First Submitted

January 28, 2019

First Submitted That Met QC Criteria

January 28, 2019

First Posted (Actual)

January 30, 2019

Study Record Updates

Last Update Posted (Actual)

June 2, 2026

Last Update Submitted That Met QC Criteria

May 29, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 18-010370
  • NCI-2021-02676 (Registry Identifier: CTRP (Clinical Trials Reporting Program))

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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