Lymphatic drainage patterns in head and neck lymphoedema: a preliminary imaging study with indocyanine green lymphography

Head and neck lymphoedema occurs frequently after head and neck cancer treatment and causes physical and psychosocial disability. Imaging is not routinely used to diagnose or inform its conservative treatment. Indocyanine green (ICG) lymphography is used for these purposes in upper and lower limb lymphoedema. Aim: The study aimed to explore the clinical potential of ICG lymphography in diagnosis and conservative management of head and neck lymphoedema. Methods: Participants underwent a single examination with ICG lymphography. The tracer injection sites were determined by anatomic lymphatic territories. Presence of dermal backflow was used to diagnose lymphoedema. Imaging data were recorded using a bespoke audit tool to document lymphatic movement features and manual lymphatic drainage observations. Results: Six participants underwent head and neck ICG lymphography. Lymphatic vessels and dermal backflow were visualised in all participants. Manual lymphatic drainage observations suggested all participants required very firm pressure to move the ICG dye through areas of dermal backflow, whereas only light pressure was required in areas with linear lymphatic vessel flow. Conclusion: ICG lymphography can identify lymphatic structures and drainage patterns in the head and neck region and is considered a potential tool for diagnosis and conservative treatment planning for head and neck lymphoedema.