Intraoperative assessment of resection margins based on raman spectroscopy in ocscc surgery

Background In head and neck oncological surgery the goal is to achieve a complete tumor resection with acceptable remaining function and appearance. For oral cavity squamous cell carcinoma (OCSCC) only 15% of the resections are reported as adequate. Since 2013, we have performed intraoperative assessment of resection margins (IOARM) in our institute, based on palpation and visual inspection of the resected specimens by pathologist and surgeon. This has resulted in an improvement of adequate resection margins from 15% to 50%, underlining the importance of IOARM. However, this method is subjective, labor intensive, and logistically challenging. Objective Our aim is to develop an objective method for fast and reliable IOARM based on Raman spectroscopy (RS). Methods RS is a non-destructive objective optical technique that provides information about the molecular composition of tissues. It can discriminate between healthy tissue and tumors. We developed a prototype Raman instrument employing a fiber-optic needle probe. The fiber-optic needle is driven into the OCSCC specimen, from the resection surface towards the tumor. Based on the Raman spectra collected along the insertion path, the location of the tumor border can be determined. From this the resection margin can be determined. Results First tests of the method show that the instrument accurately predicts the achieved resection margins. Per location the measurement and assessment takes 5 seconds. Conclusions This development signifies an important step towards a fast and objective IOARM. The fast measurement time enables an objective inspection of the margins achieved at a large number of locations of the resection surface.