Real-time imaging of tumor blood vessels during surgery

Intravital Microscopy (IVM) in Human Solid Tumors

Not applicable Interventional Mayo Clinic · NCT03823144

We will test whether a real-time microscope technique during surgery can show how well blood vessels in adults' solid tumors work and whether that helps predict if systemic cancer medicines can reach the tumor.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment85 (estimated)
Ages18 Years and up
SexAll
SponsorMayo Clinic Academic / other
Locations1 site (Jacksonville, Florida)
Trial IDNCT03823144 on ClinicalTrials.gov

What this trial studies

This trial uses human intravital microscopy (HIVM) to visualize tumor-associated blood vessels in real time during standard surgical resections. Participants receive an intravenous dose of fluorescein and surgeons record 1–2 minutes of intravital imaging per field over the tumor and nearby normal tissue. Investigators will compare vessel function between tumor and adjacent normal tissue, correlate imaging features with tumor grade on pathology, and follow patients to explore links between microvascular features and survival. The primary aim is to determine the feasibility and safety of performing HIVM in patients with deep-space solid tumors during routine operations.

Who should consider this trial

Good fit: Adults (≥18 years) with measurable solid tumors scheduled for surgical resection, ECOG performance status 0–2, who have passed a preoperative fluorescein skin-prick sensitivity test are ideal candidates.

Not a fit: Patients who are not having a surgical resection at the study site, have a positive fluorescein sensitivity test, uncontrolled intercurrent illness, or tumors not amenable to intraoperative visualization are unlikely to benefit.

Why it matters

Potential benefit: If successful, this technique could help doctors determine whether a patient’s tumor vessels are functional enough for systemic drugs to reach the tumor, enabling more informed treatment choices.

How similar studies have performed: Intravital microscopy has shown informative results in animal models and limited human pilot work, but its application to deep-space human solid tumors remains novel and largely untested.

Eligibility criteria

Show full inclusion / exclusion criteria
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

Where this trial is running

Jacksonville, Florida

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Solid Tumor, AdultClinical Stage IV Gastric Cancer AJCC v8Malignant Solid NeoplasmMetastatic Colorectal CarcinomaMetastatic Gastric CarcinomaMetastatic Primary Malignant Brain NeoplasmMetastatic SarcomaPostneoadjuvant Therapy Stage IV Gastric Cancer AJCC v8
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.