ICG 4.4, Optical Devices

One of the most innovative technologies introduced in surgery during the last years is fluorescence-guided surgery, describing a medical technology based on real-time imaging intended to help and guide the surgeon during his/her operating practice. It is based on the property of some molecules to fluoresce after being excited by specific excitation source. Among all fluorophores that could work as probes in medical imaging techniques, near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) is emerging as major contributions to intraoperative surgical decisions and many different applications have already been described in literature. Since NIR fluorescent light is essentially invisible to the human eye, special imaging systems are required to excite the NIR fluorophores within the surgical field and to collect emitted signal. This signal is then transmitted to a standard monitor allowing identification of anatomical structures where the dye is present. The system is made of an excitation source, a fluorescent probe (the dye), filters, and detector. Several clinical and fluorescence imaging systems have been developed and more systems will be developed in the near future. Fluorescence-guided surgery appears to have a great potential to become a standard in everyday clinical practice due to the multiple different possible applications.