“…Various methods of preoperative and intraoperative SLN mapping have been described including lymphoscintigraphy, 9,22,23 injection of vital dyes such as methylene blue, isosulfan blue, or patent blue violet, 5,9,15,[23][24][25][26] contrast enhanced ultrasonography, 27,28 nearinfrared florescent imaging, 5,28,29 lipid soluble iodinated contrast medium with radiography or CT, 15,18,30,31 and water soluble iodinated contrast medium (WIC) with CT. 16,17,19,20,31 The most common and current gold standard modality for SLN mapping in both human and veterinary oncology is lymphoscintigraphy that uses a radiolabeled colloid injected subcutaneously around the primary tumor site followed by assessment of the movement of radioactive particles through the lymphatic drainage system using a gamma camera. Unfortunately, lymphoscintigraphy is costly and requires special licensure for the use of a radioactive isotope and specialized equipment that limits availability of this diagnostic technique to referral centers.…”