The role of SPECT-CT in the lymphoscintigraphic identification of sentinel nodes in patients with oral cancer

Conclusion : SPECT-CT may improve the localization of sentinel nodes (SNs) in patients with oral squamous cell carcinoma (OSCC). Compared with planar lymphoscintigraphy SPECT-CT detected more SNs and provided additional anatomical and spatial information about their localization. New generation SPECT with higher resolution CT scanners are expected to provide more accurate information about the localization of SNs. Objective: To assess the role of combined SPECT-CT in SN identification in the clinically negative neck of patients with OSCC. Materials and methods: Lymphoscintigraphy comprising planar and SPECT-CT acquisition was performed in 34 consecutive patients with OSCC stage I and II (T1-2N0M0) prior to sentinel node biopsy (SNB) and selective neck dissection. The number of SNs and anatomical location was recorded according to lymphoscintigraphy and operative findings. Results: SNB was conducted in 33 patients. SNs were identified in 94% (32/34) of the patients using SPECT-CT. In 91% (29/32) of the patients SNs were harvested from all of the levels involved on SPECT-CT. SPECT-CT imaging demonstrated extra SNs compared with planar lymphoscintigraphic imaging in 47% (15/32) of patients. In seven cases the anatomical level of SN according to SPECT-CT was reclassified during surgery. The overall incidence of lymph node metastases was 19% (6/32). There were no false negative SNs.