We previously reported the SLN mapping procedure.[21 (link)] Briefly, all of the tracers were sub-mucosally injected in 4 quadrants of the cervix at 0, 3, 6, and 9 o’clock. The cervical injection was approximately 5 mm in all cases, as described previously.[22 (link)–24 (link)] On the day before the operation, 2.0 ml of fluid containing 110 MBq 99m-Technetium (99mTc)-labeled tin colloids was injected into the patient's cervix. Lymphoscintigraphy was performed within 6 hours, and hot spots—indicating SLNs—were identified. On the day of the operation, 5 ml of indigocarmine (IDC) (2 mg/mL) and/or indocyanine green (ICG) (50 μg/mL) was injected into the cervix at the start of surgery. The same quantity of IDC and/or ICG was also injected into the uterine fundus upon reaching the intraabdominal cavity. The SLNs were detected at 40 minutes after injection of IDC or ICG. Radioactive lymph nodes were located using a gamma-probe (Navigator GPS, RMD). IDC-stained lymph nodes were detected by direct inspection. ICG fluorescence-positive lymph nodes were detected using a color fluorescence camera (Hyper Wye Medical System, MIZUHO Co., for laparotomy; Camera Control Unit JC300, MC Medical Co., for laparoscopy). After SLN biopsy, the area of the pelvic lymph node was surveyed by direct observation, and with a color fluorescence camera or a gamma-probe to confirm that no radioactive tissue remained. The combination of 99mTc and IDC was used in the early phase and a combination of 3 tracers was used in the late phase.