Validity of frozen section in sentinel lymph node biopsy for the staging in oral and oropharyngeal squamous cell carcinoma.

Background and Objectives: The potential of avoiding a secondary surgery for therapeutic neck dissection (TND) by sentinel node (SN) positivity makes the intraoperative evaluation of SNs an attractive option. The aim of this study was to analyze accuracy of intraoperative frozen section (FS) for detection of occult metastases in a large single institutional patient cohort undergoing SN-biopsy.
Methods: Between 2000 and 2010, 92 consecutive patients with early stage oropharyngeal squamous cell carcinoma (OSCC) (cT1/cT2/cN0) were prospectively enrolled. Detection rate of occult metastases by monoslice FS was compared with the definitive histopathologic work up by step serial sectioning (SSS) and immunohistochemistry (IHC). In case of SN-positivity on FS TND was performed in the same narcosis.
Results: 15/92 patients revealed positive SNs by FS compared to 34/92 after SSS and IHC. Sensitivity, NPV and FNR for the detection of all sizes of metastases by FS was 47, 77, and 52%, for isolated tumor cells (ITC) 8, 86, 92%, for micrometastases 43, 90, 57%, and for macrometastases 93, 98, 7%.
Conclusion: Sensitivity of FS by the monoslice depends on the metastases size and allows a single-stage procedure in half of the SN-positive patients. To improve sensitivity for small tumor deposits either a multislice-technique or molecular methods are needed.
(Copyright © 2012 Wiley Periodicals, Inc.)