Fluorescence imaging could help surgeons pinpoint metastatic lymph nodes

A molecular-targeted imaging method has depicted lymph node metastases intraoperatively in mice. In addition to providing real-time, accurate information about lymph node status, this pathology technique could set the stage for shorter operating room time and reduce unnecessary removal of healthy lymph nodes, according to the researchers whose findings will be published Jan. 15 in Cancer Research.

Quyen T. Nguyen, MD, PhD, of University of California, San Diego, and colleagues studied injectable fluorescently labeled molecules, known as ratiometric activatable cell-penetrating peptides, in mouse models. When used in mouse models, surgeons could visualize where cancer had spread with high sensitivity and specificity in metastatic sites as small as a few millimeters, according to a press release.

Traditional sentinel node mapping locates lymph nodes without providing information on metastasis. Current methods for managing prostate cancer and neck squamous cell carcinoma require removal of all susceptible lymph nodes. Cancer involvement is determined after removal.

The new method could address two challenges: intraoperative discernment of lymph nodes among surrounding tissue and intraoperative determination of lymph node metastasis.  

According to the release, the technique will decrease surgical time because the surgical team will not need to wait for pathology reports, decrease time under anesthesia and decrease unnecessary surgery on noncancerous lymph nodes.