Sentinel Lymph Node Biopsy in Malignant Eyelid Tumor: Hybrid Single Photon Emission Computed Tomography/Computed Tomography and Dual Dye Technique

Abstract

To study the utility of hybrid single photon emission computed tomography / computed tomography (SPECT/CT) scan and dual-dye technique in identification of the sentinel lymph node (SLN) in patients with an advanced malignant eyelid tumor. Nonrandomized prospective interventional study. setting: A tertiary eye care center. study population: Patients with an advanced malignant eyelid tumor without clinically involved regional lymph nodes. intervention: SLN biopsy was performed using dual-dye technique (a combination of radiotracer and vital blue dye) following localization by SPECT/CT. main outcome measures: Localization of SLN in the regional node basin by hybrid SPECT/CT scan; SLN identification rate using dual-dye technique; SLN positivity rate; false-negative rate; and complications, if any, of SLN biopsy. Sixteen patients of biopsy-proven eyelid malignancy (7 squamous cell carcinomas [43.75%], 5 sebaceous cell carcinomas [31.25%], and 4 malignant melanomas [25%]) were included in the study. Preoperative localization of SLN was performed using SPECT/CTin 12 patients. SLN biopsy using dual-dye technique was performed in 16 patients. SPECT/CT accurately localized SLN in 11 out of 12 patients. The preauricular region was the most common site of SLN. SLN identification rates for dual-dye, radiotracer, and blue dye techniques were 100% (16/16 patients), 100% (16/16 patients), and 87.5% (14/16 patients), respectively. SLN showed metastasis in 2 patients (12.5%). On follow-up, 1 patient developed cervical lymph node metastasis, thus giving a false-negative rate of 7.14%. There were no complications associated with SLN biopsy. Accurate preoperative localization of SLN in relation to adjacent anatomic structures using SPECT/CT aids in intraoperative identification of SLN. SLN biopsy should be considered in patients with eyelid tumors at significant risk for metastasis who have clinically negative nodal basins. Dual-dye technique is safe and feasible in advanced eyelid tumors. Blue dye technique can be used for SLN biopsy in settings where nuclear medicine facilities are not available, albeit with a lower SLN identification rate. Detection of metastasis in SLNs in ∼12% of cases emphasizes the utility of SLN biopsy in accurate staging and treatment of eyelid malignancies.