Study of Near-Infrared Imaging with Indocyanine Green for Detection of Sentinel Lymph Nodes in Patients with Vulvar Cancer
This clinical trial compares how well near-infrared imaging with indocyanine green (ICG) contrast agent works for the detection of sentinel lymph nodes (SNL) with lymphoscintigraphy in patients with vulvar cancer. Sentinel lymph nodes are the first lymph nodes affected by cancer that is spreading from the primary cancer site. Evaluation of these lymph nodes can be useful for determining prognosis and staging of vulvar cancer. ICG-NIR imaging involves injecting a dye called indocyanine green (ICG) in the area of the tumor. ICG is fluorescent (it glows); therefore lymph nodes that have absorbed ICG are detected with a camera that emits a special light (near-infrared or NIR light). SLN mapping is done to identify the first lymph node to which vulvar cancer would most likely spread (the sentinel lymph node), so this lymph node can be removed and tested. Lymphoscintigraphy involves injection of a radioactive dye (radiocolloid) near the tumor. The radiocolloid contains a small amount of radiation, and the dye travels through the body to the nearest lymph nodes. A special picture is taken with a device called a scintillation camera that shows where the radiocolloid has been taken up by the lymph nodes. In the operating room, the surgeon uses that picture and a device called a gamma counter to help detect and remove the sentinel lymph node. Other purposes of this trial include studying: the length of time for lymphoscintigraphy, the length of time for ICG-NIR imaging, the size of surgical cuts (incisions) made for the biopsy, and the side effects of surgery after 30 days. Researchers think that using ICG-NIR imaging alone for SLN mapping may be as effective as using it in combination with lymphoscintigraphy, which is a more time consuming and uncomfortable procedure in patients with vulvar cancer.