All patients will receive the standard of care for SLN mapping, namely technetium-99m sulfur colloid lymphoscintigraphy. In addition, patients will be injected with indocyanine green (ICG) diluted in human serum albumin (HSA). ICG is already FDA approved for other indications and is used in this study at 400-fold to 2000-fold lower than the typical clinical dose. Dilution into HSA improves the brightness of ICG by over 3-fold, making it an excellent tracer for lymphatic flow.