Green Light Leiden

Green Light Surgery: The Basics

The Green Light Leiden group at Leiden University Medical Center (LUMC), headed by Dr. Vahrmeijer focuses on safe and efficient clinical translation of fluorescence-guided surgery applications to improve personalized clinical practice and enhance patient outcome.

Green Light Surgery at a glance

  • Fluorescence-guided surgery is an emerging multidisciplinary technique for improving cancer diagnostics and the success of surgical treatment.
  • A fluorescent label attached to a marker (e.g. a monoclonal antibody) that binds specifically and selectively to tumour cells, helping the surgeon 'see' the tumour and metastatic tissue in real time.
  • Fluorescent markers can be used with a wide range of procedures, including classic ('open') surgery, laparoscopic surgery, and diagnostic procedures such as colonoscopy.
  • The fluorescent markers are pharmacologically inactive and are safe to use in both healthy volunteers and patients.


A near infrared fluorescent marker is administered intravenously to the patient. The probe is transported though the body and accumulated in the target (tumor) tissue. Off-target binding in e.g. liver occurs in the distribution phase and once the probe is cleared from these sites, a clear fluorescent spot remains around (in the case of ICG) or in (n the case of tumor specific probes) the tumor. 

For more detailed information on the principles of fluorescence-guided surgery, see our reviews:


The mechanics of NIR fluorescence imaging. A NIR fluorescent contrast agent is administered intravenously, topically, or intraparenchymally. During surgery, the agent is visualized using a NIR fluorescence imaging system of the desired form factor, i.e., above the surgical field for open surgery or encased within a fiberscope for minimally-invasive and robotic surgery (open surgery form factor shown). All systems must have adequate NIR excitation light, collection optics and filtration, and a camera sensitive to NIR fluorescence emission light. An optimal imaging system includes simultaneous visible (i.e., white) light illumination of the surgical field, which can be merged with NIR fluorescence images. The surgeon display can be one of several forms factors including a standard computer monitor, goggles, or a wall projector (monitor form factor shown).

4.c. 4.d.

Examples of visible and near infrared fluorescent pictures of a tumor specific marker 4 hours after intravenous administration. The tumor lesions of this ovarium cancer patient are clearly visible as bright stars in the dark sky on the abdominal cavity. See Hoogstins CE et al. A Novel Tumor-Specific Agent for Intraoperative Near-Infrared Fluorescence Imaging: A Translational Study in Healthy Volunteers and Patients with Ovarian Cancer. Clin Cancer Res. 2016 Jun 15;22(12):2929-38