Indocyanine green fluorescence imaging, sentinel lymph node mapping in patients with vulvar cancer: peritumoral injection dosage and waiting times in our experience

Abstract

Background Vulvar cancer is a rare gynecological malignancy that primarily affects women of postmenopausal age. Treatment is mainly surgical, particularly for vulvar squamous cell carcinoma, the most prevalent histotype. In patients with unifocal tumors with a maximum diameter of <4 cm, in the absence of suspected inguinal lymph nodes, sentinel lymph node (SLN) biopsy is recommended. The use of a radioactive tracer is mandatory; the use of the vital blue dye is optional. Results Two patients diagnosed with vulvar squamous cell carcinoma (FIGO IB stage) underwent bilateral radical vulvectomy, SLN search and removal, and bilateral inguinal lymphadenectomy at the Cannizzaro Hospital Operative Unit of Obstetrics and Gynecology Department (Catania, Italy). Three milliliters of indocyanine green (ICG) 0.5 mg/mL was administered in 3 peritumoral injections under general anesthesia to screen the SLN. The images were acquired using an intraoperative infrared camera system, which allowed intraoperative visualization of the SLN. An SLN was identified for each patient. The lymph nodes examined by the pathologist were negative for metastatic localization of the disease. However, patients underwent bilateral inguinofemoral lymphadenectomy, as this procedure is not currently codified as a gold standard for the detection of SLN in vulvar cancer. All the lymph nodes removed were negative for the localization of vulvar carcinoma metastases. Conclusions The potential of the administration of indocyanine green (ICG) allows the execution of SLN biopsy, avoiding the multiple administrations of radiocolloid in the pre-operative phase, painful for the patient, elimination, and exposure to radioactivity. Therefore, while requiring standardization of the methodology and a large-scale application, this procedure could open a new surgical management perspective in patients with early-stage vulvar cancer.