Transvaginal ultrasound-guided myometrial injection of radiotracer (TUMIR): a new method for sentinel lymph node detection in endometrial cancer.

OBJECTIVE: The objective of this prospective study was to determine the feasibility, safety and performance of a new method for sentinel lymph node (SLN) detection in endometrial cancer (EC) using transvaginal ultrasound-guided myometrial injection of radiotracer (TUMIR). METHODS: From 2006 to 2011, 74 patients with high-risk EC were included in the study. Twenty-four hours before surgery 148MBq of (99m)Tc-nanocolloid (8mL) was injected into two spots in the anterior and posterior myometrium using an ultrasound-guided transvaginal puncture. SLN was localized preoperatively by lymphoscintigraphy and intraoperatively with gamma probe. After SLN biopsy the patients underwent a complete laparoscopic pelvic and paraaortic lymphadenectomy. RESULTS: The TUMIR method was successfully achieved in 67/74 patients (90.5%). SLN was identified in 55 women (74.3%). No adverse effects were observed. Pelvic drainage was observed in 87.2% of women and paraaortic SLN was identified in 45.4%, with 12.8% of the patients draining only in this area. The mean number of SLN retrieved was 2.8 per patient (range 1 to 9). Metastatic disease was found in 13 (23.6%) patients. Metastatic involvement of the paraaortic lymph nodes was observed in 4 (30.7%) cases. All were identified by TUMIR. The sensitivity and negative predictive value of SLN detected by TUMIR to detect metastasis were 92.3% (95% CI 22.9-100) and 97.7% (95% CI 82.0-100), respectively. CONCLUSIONS: TUMIR is a safe, feasible method to detect SLN in patients with EC, has a good detection rate and provides representative information of the lymphatic drainage of EC.