Detection of sentinel nodes by lymphoscintigraphy and gamma probe guided surgery in vulvar neoplasia

Pathologic lymph node status is the most important prognostic factor in vulvar cancer; however, complete inguinofemoral node dissection is associated with significant morbidity. Intraoperative lymphoscintigraphy associated with gamma detecting probe-guided surgery has proved to be reliable in the detection of sentinel node (SN) involvement in melanoma and breast cancer patients. The present study evaluates the feasibility of the surgical identification of inguinal sentinel nodes using lymphoscintigraphy and a gamma detecting probe in patients with early vulvar cancer.

Technetium-99-labeled colloid human albumin was administered perilesionally in 44 patients. Twenty patients had T1 and 23 had T2 invasive epidermoid vulvar cancer; one patient had a lower-third vaginal cancer. An intraoperative gamma detecting probe was used to identify SNs during surgery. Complete inguinofemoral node dissection was subsequently performed. SNs underwent separate pathologic evaluation.

A total of 77 groins were dissected in 44 patients. SNs were identified in all the studied groins. Thirteen cases had positive nodes: the SN was positive in all of them; in 10 cases the SN was the only positive node. Thirty-one patients showed negative SNs: all of them were negative for lymph node metastasis.

Lymphoscintigraphy and SN biopsy under gamma detecting probe guidance proved to be an easy and reliable method for detection of SNs in early vulvar cancer. If these preliminary data will be confirmed, the technique would represent a real progress towards less aggressive treatment in patients with vulvar cancer.