Assessing lymphatic response to treatments in head and neck cancer using near-infrared fluorescence imaging

Abstract

ABSTRACT Care for head and neck (HN) cancer could be improved with better mapping of lymphatic drainage pathways in HN region as well as understanding the effect of the cancer treatments on lymphatics. In this study, near-infrared fluorescence imaging is being used to visualize the lymphatics in human subjects diagnosed with HN cancer before and after treatments. Imaging results show the lymphatic architecture and contractile function in HN. Reformation of lymphatics during the course of cancer care was also seen in the longitudinal imaging. This allows us to better understand the lymphatics in HN cancer patients. Keywords: Near-infrared fluorescence imaging, Lymphatics, Head and Neck cancer 1. INTRODUCTION With more than 50,000 new head and neck (HN) cancer cases each year in the US, it is expected that as many as 75% will encounter HN lymphedema (LE) following surgical dissection and/or radiation therapy. [1] Cancer-treatment-related toxicity to lymphatic tissues in the HN region coul d significantly diminish cancer survivor’s quality-of-life. As with many cancers, sentinel lymph node biopsy and lymph node dissection is part of an aggressive treatment scheme. Yet while lymphatic mapping is well established in other portions of the body, the lymphatic drainage in HN is less known and can widely vary in advanced cancers. [2,3] Recent studies suggest that upon using lymphoscintigraphy, metastatic lymph nodes are left behind due to the false negative results in one out of every three HNC patients who undergo lymph node dissection. [4] Better identification and mapping of lymphatic drainage pathways as well as understanding the effect of the cancer treatments on lymphatics would be important in efficient surgical and radiation treatment planning. Recently, the near-infrared fluorescence (NIRF) imaging technique has been successfully used to assess the lymphatic vasculature and its function in limbs. [5] In this pilot study, we sought to visualize lymphatic architecture and contractile function before and after cancer treatments using NIRF lymphatic imaging to allow better understanding of cancer treatment effects on the lymphatics and their recovery in HN cancer patients.