3D rendering and analysis of dermal backflow as an early indicator of cancer-acquired lymphedema using RGB-D and near-infrared fluorescence lymphatic imaging
Sara Bouhali, Fatima Merchant, Ron J Karni, and 2 more authors
In Medical Imaging 2024: Clinical and Biomedical Imaging , 2024
Functional lymphatics are essential for removal and transport of cellular waste and excess fluid from regional tissues and are dependent upon contractile lymphangion activity for proximal drainage into the venous blood stream. Lymphatic insufficiency in patients with chronic diseases (such as cancer acquired and primary lymphedema, autoimmune disease, and peripheral venous diseases) is manifested by progressive dermal backflow, or reverse, distal flow of lymph into the dermal capillaries caused presumably by failing lymphangions. Using near-infrared fluorescence (NIRF) lymphatic imaging with ICG as a contrast agent, we recently showed that dermal backflow provides an “early warning” indicator of lymphatic dysfunction, averaging 8 months prior to onset of clinical symptoms of breast cancer lymphedema (PMID: 35816269). We also found dermal backflow progressed or persisted over months and years in head and neck cancer survivors (PMID: 28263428), but could be resolved or reduced early after cancer treatment with 2 weeks of physiotherapy (PMID: 30694720). In this work, we develop automated determination of dermal backflow areas from NIRF lymphatic imaging in order to provide accurate, longitudinal assessment of progressing/improving lymphatic dysfunction so that effective management strategies can be clinically devised to treat lymphatic dysfunction. Specifically, we combine computer vision hardware and software with NIRF imaging to automate quantification of tissues areas demarked by dermal backflow. Non-clinical testing demonstrates ±3% errors in dermal backflow area determination, with clinical testing on head and neck cancer survivors underway to assess efficacy of physiotherapies provided early after cancer treatment.