Koos Boeve

190 Chapter 9 response after radiotherapy or to an early detection of local or regional recurrences [111]. In chapter 8 we demonstrated the detection of OSCC cells in saliva using methylation markers. Although some small studies showed already promising results with the detection of CTCs or ctDNA of OSCCs in body fluids such as plasma and saliva, clear validation with large and prospective data is lacking [111].