Near-infrared fluorescence imaging of lymphatics in head and neck lymphedema

Objectives Treatment of lymphatic disease is complicated and controversial due to the limited understanding of the lymphatic system. Cancer-related lymphedema (LE) is a common complication that arises after irradiation and/or surgical excision of lymph nodes for cancer treatment. Head and neck lymphedema (HNL) is especially debilitating because of the limited options for treatment. Complicated geometry and complex lymphatic structure in the head and neck region make managing HNL difficult. Herein, we describe the compassionate use of an investigatory technique of near-infrared (NIR) fluorescence imaging together with 3-dimensional photogrammetry (3DP) to understand the lymphatic anatomy and function, and to help better manage the disease, in a subject with HNL.

Methods Immediately after 9 intradermal injections of 25 µg indocyanine green each in the face and neck region, skin surface was illuminated with a diffused excitation light, and NIR fluorescence images were collected using a custom-built imaging system. Manual lymphatic drainage (MLD) therapy was performed through the guidance of the images. Also, 3DP of the face was used to monitor response to therapy.

Results NIR fluorescence images revealed some abnormal lymphatic structures in the head and neck region, and helped identify some functioning vessels and draining lymph nodes. Using 3DP, precise geometry of facial structure was obtained, and detection of small changes in edema between therapy sessions was achieved. This analysis allowed longitudinal assessment of LE to evaluate the effect of therapy.

Conclusions In this study, we were able to map head and neck lymphatics and direct MLD in HNL using NIR fluorescence imaging, and to assess therapy efficacy using 3DP.

Research Support This work was supported by the Longaberger Foundation through an American Cancer Society Research Scholar Grant (RSG-06-213-01-LR) and the National Institutes of Health (R01 HL092923 and U54 CA136404)