Use of Charcoal Carbon Dye in Sentinel Lymph Node (SLN) Mapping in Early Stage Cervical Cancer

Cervical cancer continues to be a global health problem despite the advances in prevention, screening and treatment in preinvasive stages. Although radiotherapy is the mainstay of treatment across all stages, surgery with radical and non-radical hysterectomy with pelvic lymph node evaluation is preferred in younger women with early stage cervical cancer who wants to preserve ovarian and sexual functions that may otherwise be hampered by radiotherapy. Lymph node evaluation is critical during and/or after surgery (usually before hysterectomy) and offered by global institutions since hysterectomy during surgery is abandoned in case of a metastasis in pelvic / paraaortic lymph node(s) and/or necessities primary chemoradiation or adjuvant therapy as a therapeutic modality.

During the last 10-15 years surgical sentinel lymph node (SLN) evaluation instead of complete dissection pelvic / paraaortic lymphadenectomy has gained popularity with equal success, especially in cervical tumors with less than 2-4 cm in diameter. Besides, all other advantages of sentinel lymph node evaluation is alike the advantages of other sentinel lymph node evaluation in various other cancers (vulva, breast, endometrial cancers..) with less morbidity such as less vascular injury, lymphedema, lymphocyst formation and etc. Various tracers have been used for sentinel lymph node detection in cervical cancer surgery but indocyanine green (ICG) use has surpassed other SLN mapping tracers and methods and it is the most common agent for detecting SLN in gynecologic oncology. However, it needs a fairly expensive equipment and expertise either by laparoscopy or laparotomy. In the present study, investigators are planning to use charcoal carbon dye (CCD) in addition to ICG as their usual method for SLN mapping. CCD is commonly used by general surgeons for marking of colon during preoperative colonoscopy to delineate the point of resection in surgery for colorectal resection. It is cheap and does not require special equipment and easy to learn. CCD is planned to be given just as the same as giving ICG to the cervix with 1 cc injection at each site of external os (3 and 9 o'clock position, 0.5 cc given to submucosal area and 0.5 given stroma of cervix). 20 minutes following the injection of both agents, laparoscopic dissection of retroperitoneal area will be performed to detect pelvic and paraaortic sentinel lymph nodes (up to inferior mesenteric artery) with ICG and/or CCD.

The aim of the present study is to compare the efficacy of CCD in sentinel lymph node mapping compared to ICG mapping regarding detection rates, sensitivity, specificity, negative and positive predictive values in early stage cervical cancers (IA2 - IB2).