Assessment of bony resection margins in oral cancer using elastic scattering spectroscopy: a study on archival material.

Oral squamous cell carcinoma has been shown to infiltrate local bone necessitating either a local or segmental resection for clearance. The current decalcification process takes several weeks before histological examination of the margins is possible. The aim of this study was to determine whether elastic scattering spectroscopy (ESS) could be used to identify bone resection margins positive for tumour. We used an ESS biopsy (optical biopsy) system to assess formalin fixed bone margins resected for squamous cell carcinoma of the oral cavity and compared the results with the histopathological diagnosis. Archival specimens obtained in oral cancer resections over the last 10 years were used, the ESS spectra were obtained from residual resection margins immediately adjacent to the area from which sections were cut and the results correlated with the histopathological diagnosis. Three hundred and forty-one spectra were used in this study taken from the mandibular specimens of 21 patients, of which 231 spectra were taken from histologically positive sites and the rest were of normal tissue. Two different sets of spectra were obtained and using a linear discriminant analysis, a sensitivity of 87% and a specificity of 80% were obtained. These results suggest that ESS may identify tumour involvement of resection margins. This study, on formalin fixed tissue, was shown to be reliable and may significantly reduce pathology workload. If these findings can be applied in vivo, this would be an accurate and instant mechanism for assessment of margins in clinical practice.