Lymphatic mapping of sentinel nodes in early vulvar cancer

The aim of the study was to determine the diagnostic accuracy and feasibility of sentinel lymph node (SLN) detection using a gamma probe in patients suffering from vulvar cancer.

From May 1998 to November 2000, 26 patients with early vulvar cancer, planned for local wide excision or vulvectomy including groin dissection, were eligible for the study. Two to 3 h before the planned procedure we injected technetium(99) m-labeled microcolloid intradermally at four locations around the tumor. Dynamic and static images were recorded using a gamma camera. SLN locations were marked on the overlying skin. In the operating theater SLNs were identified at the beginning of the procedure using a handheld gamma-detection probe. After resection of suspected SLNs a standard unilateral or bilateral groin dissection was performed, subsequently followed by local wide excision or, if indicated, radical vulvectomy. Sentinel node detection using technetium(99) m-labeled microcolloid was compared with final histopathological and immunohistochemical results.

Scintigraphy showed focal uptake in all 26 patients. Intraoperatively we detected all sentinel nodes by handheld gamma probe. In 20 patients, one sentinel node was identified unilaterally, while in 6 patients two or more nodes were identified bilaterally. Histologically positive SLNs were found in 9 patients. In our preliminary series we did not find any false-negative SLN.

Identification of sentinel nodes in vulvar cancer is feasible with preoperatively administered technetium(99)m-labeled microcolloid. We confirm the results of previous studies and improve the evidence that the SLN procedure could be implemented in future therapy concepts.