Fluorescence Guided Surgery FAQ
What is Fluorescence Guided Surgery?
Fluorescence Guided Surgery (FGS) is a medical imaging technique that uses fluorescent dye to identify bodily structures during surgical procedures. FGS typically involves three components:
1. Fluorescent Dye: The most commonly used fluorescent agent is Indocyanine Green (IGC), though a number of other application-specific dyes are being actively developed around the world, such as OTL38 for cancer surgeries.
2. An Excitation Source: The fluorescent dyes used in FGS are excited by a light source that emits light in very specific near-infrared wavelengths which will cause the dye to fluoresce (or ‘glow’) and highlight the target structure.
3. A Detection Technique: The near-infrared spectrum of light that FGS dyes operate in is not visible to the human eye. It is, however, able to be seen through the use of special cameras and light filters which can detect the near-infrared fluorescence and display it on a screen for the real-time use by the surgical team.
What are the advantages of Fluorescence Guided Surgery?
Despite many advances in preoperative medical imaging such as CT and MRI scans, surgeons still almost exclusively operate under white (visible) light during their procedures and must rely on their ability to see and feel target tissues. Unfortunately, most human tissue looks very similar under white light, and it can be very difficult to distinguish one tissue from another or to completely remove a target tissue such as a tumor. In addition, a surgeon can only see the topmost layer of tissue under white light while tissues and structures underneath will remain hidden.
FGS essentially gives the surgeon the ability to ‘see’ in a different wavelength of light that would otherwise be invisible to them. By combining this visual ability with the special dyes that glow in those wavelengths surgeons can much more precisely target or avoid certain organs or tissues. In addition, the near-infrared light used in FGS can more easily penetrate human tissues, allowing surgeons to see ‘through’ layers of tissue and organs.
In addition to allowing a surgeon to see what otherwise would be invisible, FGS has the added advantage of being a real-time imaging process. Whereas traditional imaging like X-Rays, CT Scans, and MRI scans can provide excellent images, they are all limited to providing static images.
Think of FGS as being the equivalent of giving a surgeon GPS whereas before they were working with only a map!
How Is FGS Currently Being Used?
This table from this article outlines the current clinical and preclinical fluorescence-guided surgery techniques:
|Sentinel lymph node mapping||Breast cancer||Indocyanine green (ICG) (34–37)||Clinical|
|Methylene blue (MB) (38, 39)||Clinical|
|Melanoma||ICG (40, 41)||Clinical|
|Head and neck cancer||ICG (42)||Clinical|
|Lung cancer||ICG (43)||Clinical|
|Esophagus cancer||ICG (44, 45)||Clinical|
|Gastric cancer||ICG (46, 47)||Clinical|
|Colorectal cancer||ICG (48)||Clinical|
|Anal cancer||ICG (49)||Clinical|
|Prostate cancer||ICG (50–52)||Clinical|
|Penile cancer||ICG (51, 52)||Clinical|
|Lymphography||Lymph flow||ICG (53–55)||Clinical|
|Angiography||Cerebral aneurysm||Fluorescein sodium (56–58)||Clinical|
|Coronary artery bypass grafting||ICG (59, 60)||Clinical|
|Abdominal aortic aneurysm||ICG (61)||Clinical|
|Abdominal surgery||ICG (62, 63)||Clinical|
|Reconstructive surgery||ICG (64–70)||Clinical|
|Anatomic imaging||Cholangiography||ICG (71, 72)||Clinical|
|Nerves||Various fluorescently labeled peptide (NP) (76, 77)||Preclinical|
|Parathyroid and thyroid grands||T700 and T800 fluorophores (78)||Preclinical|
|Endocrine grands||Various near-infrared fluorophores (79–81)||Preclinical|
|Tumor imaging||Malignant glioma||5-ALA (82–86)||Clinical|
|Fluorescein sodium (87–89)||Clinical|
|Brain metastases||Fluorescein sodium (92, 93)||Clinical|
|Head and neck cancer||IRDye800CW conjugate (94, 95)||Clinical|
|IRDye700DX conjugate (96)||Clinical|
|Hepatocellular carcinoma||ICG (97–100)||Clinical|
|Liver metastases||ICG (99)||Clinical|
|Breast cancer||MB (101)||Clinical|
|IRDye800CW conjugate (102)||Clinical|
|Lung and chest masses||ICG (105)||Clinical|
|Folate-fluorescein isothiocyanate (FITC) (106)||Clinical|
|Ovarian cancer||ICG (109)||Clinical|
|Pancreatic cancer||Green fluorophore conjugate (113, 114)||Preclinical|
|IRDye800CW conjugate (102)||Preclinical|
|Solitary fibrous tumor (pancreas)||MB (115)||Preclinical|
|Renal cell carcinoma||EC17 (116)||Clinical|
|Bladder cancer||5-ALA/HAL (117–120)||Clinical|
|Prostate cancer||ICG conjugate (121)||Preclinical|
|Gastric cancer||ICG (123–125)||Clinical|
|Colorectal cancer||Green fluorophore conjugate (113)||Preclinical|
|IRDye800CW conjugate (126)||Clinical|
|Basal cell carcinoma||5-ALA (128)||Clinical|
|Parathyroid adenoma||MB (130)||Clinical|
|Laparoscopic- and robotic-assisted surgeries||Nephrectomy||ICG (131)||Clinical|
|Cholecystectomy||ICG (72, 132)||Clinical|
|Adrenalectomy||ICG (135, 136)||Clinical|
|Fluorescence endoscopy||Brain aneurysm||ICG (137–139)||Clinical|
|Endonasal surgery||ICG (140–142)||Clinical|
|Angiography||ICG (142, 143)||Clinical|
|Brain tumor||ICG (140, 144, 145)||Clinical|
|Head and Neck tumor||ICG (146)||Clinical|
|Gastric cancer||ICG (123–125)||Clinical|
|Marking tumor||Colonic tattooing||ICG (147–149)||Clinical|