PhD defence C.G.F. (Cornelia) van Lanschot

Below is a brief summary of the dissertation:

Head and neck cancer is the 6th most common malignancy globally, impacting life expectancy and quality of life. Radical surgery is crucial, and resection margins are indicative of its success. The Royal College of Pathologists defines margins as clear (>5 mm), close (1-5 mm), and positive (<1 mm). Achieving clear margins reduces local recurrence risk. Intra-operative assessment aids in achieving clear margins, with specimen-driven assessment showing improved outcomes. A method using numbered tags for relocating inadequate resection margins was introduced. However, challenges in achieving >5 mm margins in larynx and hypopharynx surgeries led to proposing a new guideline advocating for maximum feasible margins > 1 mm. In laryngeal and hypopharyngeal cancers, resection margins ranging from 1-5 mm are considered acceptable, while margins less than 1 mm are associated with worse outcomes.
Another crucial histopathological factor is depth of invasion, which is considered an independent predictor for lymph node metastasis in early-stage oral cavity cancer. Retrospective studies validated a DOI cut-off of 4 mm for elective neck dissection.
Various techniques, such as ultrasound, cytology, and optical methods, are currently being explored for intra-operative use in surgical oncology. Raman spectroscopy, a non-destructive optical technique, distinguishes cancerous and healthy tissue based on molecular composition. Raman spectroscopy identified water concentration differences across tumor borders in oral cancer surgery. Raman spectroscopy was explored for laryngeal cancer differentiation, showing promise.