Objective: The purpose of this study was to examine the feasibility of sentinel lymph node (SLN) detection in patients with endometrial cancer using preoperative lymphoscintigraphy and an intraoperative gamma probe.
Patients and methods: Between June 2001 and January 2003, 28 consecutive patients with endometrial cancer who were scheduled for total abdominal hysterectomy, bilateral salpingo-oophorectomy, total pelvic lymphadenectomy, and paraaortic lymphadenectomy at Tohoku University School of Medicine underwent sentinel lymph node detection. On the day before surgery, preoperative lymphoscintigraphy was performed by injection of 99m-Technetium ((99m)Tc)-labeled phytate into the endometrium during hysteroscopy. At the time of surgery, a gamma-detecting probe was used to locate radioactive lymph nodes.
Results: At least one sentinel node was detected in each of 23 of the 28 patients (82%). The mean number of sentinel nodes detected was 3.1 (range, 1-9). Sentinel nodes could be identified in 21 of 22 patients (95%) whose tumor did not invade more than halfway into the myometrium. Eighteen patients had radioactive nodes in the paraaortic area. Most patients had a sentinel node in one of the following three sites: paraaortic, external iliac, and obturator. The sensitivity and specificity for detecting lymph node metastases were both 100%.
Conclusion: The combination of preoperative lymphoscintigraphy with intraoperative gamma probe detection may be useful in identifying sentinel nodes in early-stage endometrial cancer.