Development of Raman Spectroscopy Tools for Surgery Guidance in Head & Neck Oncology

Clinical necessities in surgical oncology are based on the same fundamental issue: lack of pre- and intra-operative methods with sufficient and/or clinically relevant sensitivity and specificity. This thesis provides a technical solution for these clinical necessities in head and neck surgical oncology.
In this thesis we investigated the potential of Raman spectroscopy for ex-vivo intra-operative surgical guidance.
This thesis shows that oral cavity squamous cell carcinoma (OCSCC) can be discriminated from surrounding healthy soft tissue and healthy bone using Raman spectroscopy with a high sensitivity and specificity (respectively, sensitivity of 99% and 96% and specificity of 92% and 83%). The discrimination is mainly based on the water concentration of these tissues, determined by using the Raman spectrum. OCSCC has more water content than the surrounding healthy tissue or bone. The information on the water concentration also proved to be useful for detection of the OCSCC border.
To guarantee that the calculation of the water concentration and the processing of the spectra is not influenced by noise or signal that did not result from Raman scattering, a method (multiple regression fitting, MRF) for subtraction of luminescence background was created. Its performance was compared to the current most used method (polynomial baseline fitting, PBF). Results indicate that MRF is more robust and therefore preferable to PBF.
Additionally, a Raman needle probe for intra-operative assessment of soft tissue resection margins was developed and is being optimized to guide surgeons towards an adequate OCSCC resection.
Finally, intra-operative use of Raman pathology systems for assessment of soft tissue resection margins and bone resection surfaces may affect positively the outcome of head and neck surgery. The intra-operative use of these tools may: decrease the number of inadequate margins, lower the rate of adjuvant radiation therapy, and decrease the mortality rate of the patients that undergo OCSCC surgery.