in cancer, especially with reference to gynecological cancers. So we start by first defining what a sentinel lymph node is. So it's defined as the first lymph node to which the cancer cells are likely to spread from the primary tumor. So SLNB, which stands for sentinel lymph node biopsy has been used in breast cancer melanoma and now in gynecological cancers. Its most established use is in endometrial cancer and vulvar cancer. And it's also currently used in cervical cancer, especially for tumors less than two centimeters. So what's the rationale behind doing an SLNB? It helps us to strike a compromise in the endometrial cancer management, but how so? So we know that lymphadenectomy is not without risk, not to mention it takes more time and skill to perform. So there are also intraoperials as the nodes are near big blood vessels, nerves, bowels, ureters. And there are also post-op complications such as lymphosis, lymphatic ascites, and lymphedema, which can actually afflict patient permanently even after she's cured of cancer. And we know that in apparent early stage endometrial cancer, the chance of nodal involvement is in the region of 10%, which means that more than 80% of patients will have undergone lymphadenectomy with negative findings. However, knowing the lymph node status helps to guide treatment. If proven to be stage three, which means the nodes are involved, chemotherapy does have its role in improving survival. But yet we know that it does not have a therapeutic advantage in clearing all the nodes as proven in two randomized control trials, the ASTAC trial and the Italian trial by Panisi et al. So I feel that a sentinel lymph node biopsy is a good way of compromise. It avoids the morbidity of a full lymphadenectomy, especially in patients with negative nodes, yet provides information regarding nodal status. And of course, the other two advantages are we submit these nodes to a more detailed evaluation process which includes cutting the nodes at smaller intervals at three millimeters, and also doing immunohistochemical staining with AE1 and AE3 on top of the usual H and E stains. And on top of that, it also helps to pick up involved lymph nodes that may actually lie outside the usual lymphadenectomy boundaries, for example, in the presacral areas. So how do we detect a sentinel node? So there are many techniques that are being used. Common techniques are injection of vital blue dyes or endocyanin green, but that must be detected with an infrared camera or radioisotope around the tumor. So in endometrial cancer, ICG has emerged to be the dye that provides the highest detection rate. And we have a landmark study, the FIERS study, to show that actually the sentinel lymph node can be a valid representation of the status of all the nodes. So this is by Emma Rossi and team, which is a multi-center prospective cohort study with 385 patients who underwent sentinel lymph node biopsy followed by full pelvic lymphadenectomy and optional para-aortic lymphadenectomy. And they recruited clinically apparent stage one endometrial cancers of all histologies and grades. And ICG was used for sentinel node mapping. And the trial results can be summarized in this slide. So 86% of patients had successful mapping of at least one sentinel lymph node. The sensitivity of the detecting nodal mats was 97.2%. And they have a very good negative predictive value of 99.6%. So the authors conclude that sentinel lymph nodes can safely replace full lymphadenectomy in the staging for endometrial cancer. However, this will mean that 3% of the patients with no positive disease are missed, but it spares many others from the morbidity of a complete lymphadenectomy. And we also know from the NCCN guidelines that there must be appropriate surgical specialty and expertise and attention to detail is critical. So, and the selected cases must have you try and confine disease on imaging and on intraoperative survey. So this diagram is from the NCCN guidelines. It shows that cervical injection is a useful and validated method for endometrial cancer and the possible methods of injection and areas where the injections can take place are shown. And usually if you look at a diagram on the bottom left, the dye will follow lymphatic channels and condense at a parametrial area before crossing over to the obituary that umbilical artery to the media aspect of the external islet vessels or the ventral portion of the internal islet artery or the superior portion of the obturator vessels. So this is the most common path and on diagram on the right, there's a less common path, which means the dye follows the mesoyurita and appear at the presacral region. So it is crucial that the Sentinel lymph node algorithm must be followed to ensure a good outcome. So the most important thing is to open all the retroperitoneal spaces and carefully inspect it. All mapped nodes must be removed and submitted for ultrastaging and any suspicious nodes must be removed regardless of mapping. So I usually based it on the pre-op scan imaging and speak to the radiologist to localize where these enlarged nodes are. And if there's no mapping on a hemipelvis, a site-specific lymph node dissection should be performed and a paralytic lymph node dissection is done at the attending doctor's discretion. So I'll conclude here by showing a video of one of my cases. So what we do is that a patient is positioned after general anesthesia and a dye is injected before we scrub. The patient is then cleaned and draped, the uterine manipulator inserted and the abdomen is entered and a survey is performed. So I'll just play the video and just make comments accordingly. So that's the round ligament that we're cutting through to get to the retroperitoneal space. So in this case, I use the ligature device. I find that it's pretty useful and it hastens things. So that's the peripheral cycle space that we're opening and we look for all the landmarks that we usually do. That's the obturator nerve that is seen and my left hand is actually tracking on the obliterated umbilical artery. You can see the green tracks, the ICG dye is crossing over the parameter in this case and going to the obturator node. Okay, so this node is here and we have the pinpoint system that confirms that this is the first node and most probably the sentinel node. However, there was another node on the external islet vessel that I decided to remove as well just to send it for testing and I remove all these nodes in the back to prevent any port side metastasis. Now, these nodes will be sent for routine histology then we procedure lymphadenectomy if the nodes are positive as the patient is given adjuvant chemotherapy this node positive. Okay, we're done with the presentation. Are there any questions?

sentinel lymph node biopsy

endometrial cancer

lymphadenectomy

vital blue dyes

endocyanin green