Application of methylene blue sentinel lymph node mapping in endometrial cancer

Abstract

Objective To investigate the value of methylene blue sentinel lymph node (SLN) mapping in endometrial cancer. Methods 67 patients of endometrial cancer underwent radical or total hysterectomy + oophorectomy and pelvic ± para-aortic lymphadenectomy. The methylene blue dye was injected to the cervix at 4 locations (3, 6, 9 and 12 o’clock) 2 hours before the operation. The number of sentinel lymph node and locations were observed and recorded during the operation. All of the lymph nodes were analyzed by hematoxylin and eosin and immunohistochemistry. Results Of 67 patients, 53 cases underwent laparoscopic operation and 14 underwent robotic operation. Overall and bilateral detection rates were 82.0% (55/67) and 71.6% (48/67), respectively, the sensitivity was 87.5% (7/8), the false negative rate was 12.5% (1/8). The median number of removed SLNs, pelvic lymph node and para-aortic lymph node was 2, 7, 0, respectively. The anatomic distribution of SLN were mostly in obturator fossa and external iliac artery. Conclusions Sentinel lymph node mapping with high sensitivity and simple operation, can be used as conventional method of surgery for endometrial cancer predicting the overall situation of pelvic lymph node metastasis. Key words: Endometrial cancer; Sentinel lymph node; Methylene blue; Lymphatic mapping