Sentinel lymph node biopsy in endometrial cancer-Feasibility, safety and lymphatic complications

Objective: To compare the rate of lymphatic complications in women with endometrial cancer undergoing sentinel lymph node biopsy versus a full pelvic and infrarenal paraaortic lymphadenectomy, and to examine the overall feasibility and safety of the former. Methods: A prospective study of 188 patients with endometrial cancer planned for robotic surgery. Indocyanine green was used to identify the sentinel lymph nodes. In low-risk patients the lymphadenectomy was restricted to removal of sentinel lymph nodes whereas in high-risk patients also a full lymphadenectomy was performed. The impact of the extent of the lymphadenectomy on the rate of complications was evaluated. Results: The bilateral detection rate of sentinel lymph nodes was 96% after cervical tracer injection. No intraoperative complication was associated with the sentinel lymph node biopsy per se. Compared with hysterectomy alone, the additional average operative time for removal of sentinel lymph nodes was 33. min whereas 91. min were saved compared with a full pelvic and paraaortic lymphadenectomy. Sentinel lymph node biopsy alone resulted in a lower incidence of leg lymphedema than infrarenal paraaortic and pelvic lymphadenectomy (1.3% vs 18.1%, p = 0.0003). Conclusion: The high feasibility, the absence of intraoperative complications and the low risk of lymphatic complications supports implementing detection of sentinel lymph nodes in low-risk endometrial cancer patients. Given that available preliminary data on sensitivity and false negative rates in high-risk patients are confirmed in further studies, we also believe that the reduction in lymphatic complications and operative time strongly motivates the sentinel lymph node concept in high-risk endometrial cancer

Description of a reproducible anatomically based surgical algorithm for detection of pelvic sentinel lymph nodes in endometrial cancer

Objective: To describe and evaluate a reproducible, anatomically based surgical algorithm, including reinjection of tracer to enhance technical success rate, for detection of pelvic sentinel lymph nodes (SLNs) in endometrial cancer (EC). Methods: A prospective study of 102 consecutive women with high risk EC scheduled for robotic surgery was conducted. Following cervical injection of a fluorescent dye, an algorithm for trans- and retroperitoneal identification of tracer display in the lower and upper paracervical pathways was strictly adhered to. To enhance the technical success rate, this included ipsilateral reinjection of tracer in case of non-display of any lymphatic pathway. The lymphatic pathways were kept intact by opening the avascular planes. To minimize disturbance from leaking dye, removal of SLNs was first performed along the lower paracervical (presacral) pathways followed by the more caudal upper paracervical pathways. In each pathway, the juxtauterine node with an afferent lymph vessel was defined as an SLN. After removal of SLNs, a complete pelvic and, unless contraindicated, infrarenal paraaortic lymph node dissection was performed. Results: The bilateral detection rate including tracer reinjection was 96%. All 24 (23.5%) node positive patients had at least one metastatic SLN. Presacral lymph node metastases were discovered in 33.3% of the node positive patients. One patient (4.2%) had an isolated presacral lymph node metastasis. Conclusions: The described cranial-to-caudal anatomically based surgical SLN algorithm, including a presacral dissection and reinjection of tracer, results in a high SLN detection rate and identified all patients with lymph node metastases

A study on uterine lymphatic anatomy for standardization of pelvic sentinel lymph node detection in endometrial cancer

Objective: To describe the anatomy of uterine lymphatic drainage following cervical or fundal tracer injection to enable standardization of a pelvic sentinel lymph node (SLN) concept in endometrial cancer (EC). Methods: A prospective consecutive study of women with EC was conducted. A fluorescent dye (Indocyanine green) was injected into the cervix (n = 60) or the uterine fundus (n = 30). A systematic trans- and retroperitoneal mapping of uterine lymphatic drainage was performed. Positions of the pelvic SLNs, defined by afferent lymph vessels, and lymph node metastases were compared. Results: Two consistent lymphatic pathways with pelvic SLNs were identified irrespective of injection site; an upper paracervical pathway (UPP) with draining medial external and/or obturator lymph nodes and a lower paracervical pathway (LPP) with draining internal iliac and/or presacral lymph nodes. Bilateral display of at least one pelvic pathway following cervical and fundal injection occurred in 98% and 80% respectively (p = 0.005). Bilateral display of both pelvic pathways occurred in 30% and 20% respectively (p = 0.6) as the LPP was less often displayed. Nearly one third of the 19% node positive patients had metastases along the LPP. No false negative SLNs were identified. Conclusions: Based on uterine lymphatic anatomy a bilateral detection of at least one SLN in both the UPP and LPP should be aimed for. Absence of display of the LPP may warrant a full presacral lymphadenectomy. Although pelvic pathways and positions of SLNs are independent of the tracer injection site, cervical injection is preferable due to a higher technical success rate

Combining Indocyanine Green and Tc99-nanocolloid does not increase the detection rate of sentinel lymph nodes in early stage cervical cancer compared to Indocyanine Green alone

Objective: To investigate whether combining two independent tracers increases the SLN-detection rate in cervical cancer. Methods: Consecutive women with early stage cervical cancer planned for a robotic radical hysterectomy or a robotic radical trachelectomy with sentinel lymph node (SLN) detection were included. After cervical injections of Indocyanine green (ICG) and Tc99-nanocolloid (Tc99), near-infrared fluorescence imaging and a gamma probe were used to identify SLNs in the upper and lower paracervical pathways (UPP/LPP). A strict surgical algorithm was adhered to and the SLNs were defined as SLN-ICG, SLN-ICG+Tc99 or SLN-Tc99. In FIGO-stage ≥IA2 cancers a full pelvic lymph node dissection (PLND) was performed after detection of SLNs. The primary endpoint was the SLN detection rate per tracer and combination of tracers. Secondary endpoints were sensitivity and mapping rates of the SLN algorithm per tracer and combination of tracers. Results: In the sixty-five analyzed women, the bilateral mapping rate was 98.5% for ICG and 60% for Tc99 (p < 0.01). Combining the tracers did not increase the bilateral detection rate. In three women (5%) Tc99 identified ICG-negative non-metastatic SLNs without impact on the bilateral detection rate. Eight women (12%) had lymph node metastases (LNMs), all had at least one metastatic SLN. Seven (35%) of the 20 metastatic SLNs were detected by ICG only and 12 (60%) were ICG and Tc99 positive. Conclusion: SLN detection rate was significantly higher using ICG compared with Tc99. ICG identified all patients with LNMs. Combining ICG and Tc99 did not improve the bilateral detection rate of SLNs

Resection of the upper paracervical lymphovascular tissue should be an integral part of a pelvic sentinel lymph node algorithm in early stage cervical cancer

Objective: To investigate the prevalence of lymph nodes and lymph node metastases (LNMs) in the upper paracervical lymphovascular tissue (UPLT) in early stage cervical cancer. Methods: In this prospective study consecutive women with stage IA1-IB1 cervical cancer underwent a pelvic lymphadenectomy including identification of sentinel nodes (SLNs) as part of a nodal staging procedure in conjunction with a robotic radical hysterectomy (RRH) or robotic radical trachelectomy (RRT). Indocyanine green (ICG) was used as tracer. The UPLT was separately removed and defined as “SLN-parametrium” and, as all SLN tissue, subjected to ultrastaging and immunohistochemistry. Primary endpoint was prevalence of lymph nodes and metastatic lymph nodes in the UPLT. Secondary endpoints were complications associated with removal of the UPLT. Results: One hundred and forty-five women were analysed. Nineteen (13.1%) had pelvic LNMs, all identified by at least one metastatic SLN. In 76 women (52.4%) at least one UPLT lymph node was identified. Metastatic UPLT lymph nodes were identified in six women of which in three women (2.1% of all women and 15.8% of node positive women) without lateral pelvic LNMs. Thirteen women had lateral pelvic SLN LNMs with either no (n = 5) or benign (n = 8) UPLT lymph nodes. No intraoperative complications occurred due to the removal of the UPLT. Conclusion: Removal of the UPLT should be an integral part of the SLN concept in early stage cervical cancer

Similar distribution of pelvic sentinel lymph nodes and nodal metastases in cervical and endometrial cancer. A prospective study based on lymphatic anatomy

Objective: Comparing the anatomical distribution of metastatic and non-metastatic pelvic sentinel lymph nodes (SLN) in cervical and endometrial cancer. Methods: Detailed SLN mapping results were prospectively retrieved in cervical (n = 145) or high-risk endometrial cancer (n = 201) patients undergoing a robotic staging procedure. Cervically injected Indocyanine Green (ICG), allowing for reinjection in case of inadequate mapping, was used as tracer. An anatomically based definition of SLNs was adhered to evaluating the upper (UPP) and lower (LPP) paracervical lymphatic pathways. The positions of SLNs were intraoperatively depicted on an anatomical chart. A completory pelvic lymphadenectomy was performed. Mapping rates and anatomical distribution of SLNs and the location of pelvic nodal metastases were compared between groups. Results: The bilateral mapping rate was 97.9% and 95.0% for cervical and endometrial cancer respectively (p = .16). The proportion of typically positioned (interiliac and proximal obturator fossa) SLNs along the UPP was similar between groups (78.1% vs 82.1%, p = .09), and the rate of metastatic SLNs in the obturator fossa was 54.1% and 48.6% respectively (p = .45). All pelvic node positive women (cervical cancer n = 19, endometrial cancer n = 37) had at least one metastatic SLN. Anatomically typical positions could not be defined along the LPP. Conclusion: The anatomical location of SLNs and SLN metastases are similar in cervical and endometrial cancer suggesting that sensitivity results for an SLN concept in endometrial cancer and cervical cancer can be accumulated