Narrow band imaging in the intra-operative definition of resection margins in oral cavity and oropharyngeal cancer

Objectives: In oncological surgery, a three-dimensional resection 1.5-2 cm from the gross tumour edge is currently considered appropriate, and the status of resection margins is the most reliable indicator of radicality. Awareness of "field cancerization" calls for a re-evaluation of the benchmarks of tumour resection; however, its identification is not simple because the dysplastic areas may be far from the main lesion and difficult to recognize macroscopically. New technologies such as narrow band imaging (NBI) could improve the detection of neoplastic and pre-neoplastic areas, ensuring more precise resections. The main purpose of this study was to investigate the value of NBI in detecting pre-cancerous areas and/or cancer around the tumour bulk intra-operatively, to achieve adequate resection of the tumour.

Materials and methods: The resection margins of 8 oral cavity and 8 oropharyngeal cancers were first drawn by macroscopic evaluation and then re-defined using NBI. Resections were performed following the NBI-drawing if extemporaneous histological examinations of the NBI-defined enlargements were positive for dysplasia or cancer. The number of clear margins was evaluated.

Results: Resections margins were free of tumour or dysplasia at extemporaneous examination; on definitive histology, two patients had a margin positive for cancer and dysplasia, respectively. Among the NBI-defined enlargements, 25% were positive for dysplasia and 75% for cancer. The sensitivity, specificity, positive and negative predictive values were 100%, 88.9%, 100% and 87.5%, respectively.

Conclusion: The method we propose could be useful for obtaining free surgical margins and reducing the potential development of tumour foci resulting from incomplete resection.