In developed countries, endometrial cancer is the most frequent gynaecological malignancy in post-menopausal women; however, at the time of diagnosis the majority of patients shows an early stage disease with low probability of lymphatic metastasis. Nodal status is in fact one of the most important prognostic factors for Overall Survival and adjuvant therapy choice. In patients with low-risk, early stage endometrial cancer, surgical staging through systematic pelvic and para-aortic lymphadenectomy is currently under debate as it has been shown that it does not affect OS, producing often post-operative morbidity and prolonging surgery time in patients characterized by a high surgical risk profile. Aim of this study is to evaluate Sentinel Lymph Node mapping using dual intracervical injection as an alternative procedure to assess nodal involvement in this category of patients.
So far, since July 2014 five patients with endometrial cancer stage IA-IB (FIGO 2009) have been enrolled. On the same day of surgery, a total activity of 74 MBq of 99mTc-nanocolloid in a volume of 0,5 ml is injected at the two sides of the cervix; this procedure is carried out easily and with a good compliance from patients. After a mean time of 30 minutes, a planar lymphoscintigraphy is performed to evaluate radiocolloidal drainage and identify SLN, using a dual-head gamma camera, matrix size 128×128, equipped with LEHR collimator. Intraoperatively, after having performed hystero-annexectomy, a laparoscopic wireless gamma-probe is used to guide SLN localization and removal; every specimen is checked ex vivo with the gamma-probe and sent to histology. After excision, surgical field is examined to verify the absence of any residual source of significant radioactivity.
In five patients, seven SLNs were localized by lymphoscintigraphy as a bilateral drainage has been visualized in two cases. During surgery, all SLNs were efficiently identified and removed with the guide of the laparoscopic gamma-probe. Intraoperative localization always confirmed lymphoscintigraphic findings: in three cases SLN belonged to the external iliac chain and in four cases to the internal iliac chain. At histological evaluation all SLNs were negative for metastatic involvement.
As established so far by this initial experience, dual intracervical injection seems to offer a reliable and reproducible technique to localize SLN during both lymphoscintigraphic study, providing clear images of radiocolloidal drainage, and surgical procedure. Standardization of this technique could limit the extent of lymphatic dissection in early stage endometrial cancer patients, reducing post-operative morbidity and permitting SLN histological ultrastaging.