Intraoperative 3-D imaging improves sentinel lymph node biopsy in oral cancer.

PURPOSE: The aim of this study was to prospectively evaluate the feasibility and potential advantages of freehand single-photon emission computed tomography (fhSPECT) compared with conventional intraoperative localization techniques for sentinel lymph node biopsy (SLNB) in oral cancer.

METHODS: Between November 2012 and February 2014, 23 consecutive patients with clinical T1/T2 oral squamous cell carcinoma and a cN0 neck were recruited. All patients underwent SLNB followed by elective neck dissection (END). All patients received preoperative lymphoscintigraphy. To detect the SLNs intraoperatively, fhSPECT with a combination of conventional acoustic SLN localization and 3-D visual navigation was used.

RESULTS: All but one of the SLNs detected by preoperative imaging were successfully mapped intraoperatively by fhSPECT (detection rate 98%), including those in six patients with a tumour in the floor of the mouth. A histopathology analysis revealed positive SLNs in 22% of patients. No further metastases were found in LNs resected during END. SLNB correctly predicted the final LN stage in all patients (accuracy 100%). Additional radioactive LNs, which were not present on preoperative lymphoscintigraphy, were observed in three patients.

CONCLUSION: FhSPECT is a feasible technology that allows the accurate identification of SLNs in oral cancer. FhSPECT overcomes the shine-through phenomenon, one of the most important limitations of SLNB, thereby confirming the importance of SLNB in patients with cN0 oral cancer.