EP1196\u2005Radioguided detection of sentinel lymph node in vulvar cancer. Achievements and limitations

Abstract

Introduction/Background To evaluate the effectiveness and limitations of Technetium-99m for lymphoscintigraphic mapping and sentinel lymph nodes (SLNs) localization in early stage vulvar cancer patients. Methodology In prospective observational case series study 34 consecutive patients with histologically proven vulvar squamous cell cancer ≤ 4 cm in size were enrolled. Technetium-99m colloid albumin was injected intradermally around the tumor at least 3 h before surgery for lymphoscintigraphic mapping and intraoperative mobile gamma ray probe detection of sentinel nodes (SLN). SLNs were identified and removed before a complete inguinofemoral lymphnode dissection was performed, regardless of the SLN status. If no metastases were found in hematoxylin-eosin slides, immunohistochemical staining was performed for the definitive pathohistological diagnosis. Results The detection of SLN was successful in all patients. There was one patient with metastatic non-sentinel lymph node despite the negative sentinel node in which the previously performed diagnostic complete excision of tumor. The sensitivity, specificity and negative predictive value of sentinel node assay with immunohistochemistry included were 90,0% (95% CI: 55.5 to 99.7%), 100,0% (95% CI: 86.3 to 100.0%), and 96.1% (95% CI: 79.6 to 99.4%), respectively. Conclusion Lymphoscintigraphy and SLN biopsy under gamma-detecting probe guidance proved to be a reliable method for the detection of sentinel node in early vulvar cancer. The SLN biopsy is highly accurate in predicting the status of the remaining inguinofemoral lymph nodes and represents a true advance in the selection of patients for less radical surgery. Protocol of radioguided detection of SLN includes the injection of the technetium-99m-nanocolloid at least 3 h before surgery which involves two invasive procedures, transport of patient from the Nuclear medicine unit into the Operating suite. The local colloid application is almost always painful procedure for patients. All this points to the need to change the application protocol or tracer. Disclosure Nothing to disclose