NIR Imaging System Supports Breast Cancer Treatment

An innovative imaging system detects near-infrared (NIR) fluorescent light emitted from indocyanine green (ICG) to aid in the visualization of lymph and blood vessels in the breast.

The Shimadzu (Kyoto, Japan) LightVision system creates real time contrast images of the lymph system by exposing lymph vessels infused with ICG to an excitation light and detecting emissions of NIR light from the ICG (which are invisible to the naked eye) with the aid of an integrated X10 zoom digital camera. By visualizing the lymph vessels on a monitor screen, the surgeon can identify the position of sentinel lymph nodes (SNLs), which are important for diagnosing the metastasis status of cancer cells during breast cancer surgery.

The camera is mounted on an extendable arm that allows optimal positioning during procedures, while the main unit is easily controlled via a simple and detachable console. The camera supports automatic focusing, light exposure, and automatic white balance adjustment. Built-in high-definition sensors are used for image acquisition in a bright field of view, without needing to turn off lighting in the operating room. The self-supported extendable arm allows hands-free operation, reducing the burden on surgical personnel, and also displaying images without blur by eliminating hand movement.

Users can check the system operating situation and adjust image quality using another small monitor on the main unit. The system also supports simultaneous display of three concurrent images, which means that a visible light image, a NIR fluorescence image, and a combined, superimposed image can all be displayed simultaneously, in real-time, on the same screen. To better identify the position of the lymph nodes, lymph vessels, and blood vessels, the ICG areas of fluorescence can be displayed as either green or blue.

Finding metastatic cancer cells during breast cancer surgery requires first identifying the position of the SNLs, which have a diameter of just a few millimeters, and then excising them for hisotpathology. If the cancer has not yet metastasized to an SLN, axillary lymph node excision can be omitted, thus preventing subsequent lymphedema and maintaining the patient's quality of life after surgery. In recent years the interest in using fluorescence methods for SLN biopsies has been increasing.