Minimizing Surgical Side Effects with Sentinel Node Biopsy
May 24, 2018 09:54PM ● Published by Alyssa McGinnis
Gallery: Images of lymphatic mapping [6 Images] Click any image to expand.
By Alex Strauss
Surgical treatment of endometrial and cervix cancers has traditionally involved the removal of lymph nodes throughout the pelvis (as well as aortic lymph nodes in the case of endometrial cancer), along with hysterectomy.
While removing these lymph nodes can provide important diagnostic and staging information, gynecologic oncologist Luis Rojas, MD, says it also has serious drawbacks for patients.
“For many surgeons, it has been a point of pride, how many lymph nodes you were able to remove,” says Dr. Rojas. “But we have been ignoring the fact that the removal of lymph nodes from these three regions has translated into potential harm, side effects, complications, and quality of life issues for many patients.”
The rate of lymphedema after pelvic node dissection is around 47 percent. These patients often need extensive physical therapy and may be consigned to a lifetime of pressure garments and pneumatic devices.
To reduce these complications and give patients a better post-surgical quality of life, Dr. Rojas now dissects only the first set of lymph nodes into which the uterus is draining (sentinel nodes) in most endometrial and cervix cancer patients. This involves “mapping” the lymphatics by injecting a fluorescent dye into the cervix and using robotic equipment with near-infrared visualization software to identify, remove, and analyze just the sentinel nodes.
“We know that the sentinel nodes are the nodes with the highest likelihood of having metastatic disease,” says Dr. Rojas. “The idea is, if you identify those nodes and remove them, you don’t need to remove the rest to get the information you need. The technology is not perfect, but it has about a 98 percent sensitivity and specificity, so it is very accurate.”
Once the sentinel nodes are removed, pathologists process them differently, too, using more cuts and special dye, which increases the chance of finding cancer cells, if they are there. In the first 20 “test cases” done at Avera, during which both the sentinel nodes and the rest of the region’s lymph nodes were removed, analysis of the sentinel nodes was 100 percent accurate in predicting the presence of metastatic cells in other nodes.
The technique is so accurate—when done in centers like Avera with high enough volume—that the Society for Gynecologic Oncology issued a white paper in 2017 recommending it as the standard of care for most patients with endometrial or cervix cancers. Dr. Rojas estimates that 90 percent of his endometrial cancer surgeries are now done this way. He plans to present on the topic at Avera’s fall cancer symposium.