Evaluation of the response to radiotherapy with Positron Emission Tomography/Computer Tomography in head and neck carcinomas

Purpose: The aim of this study is to assessment of therapy response to radiotherapy or concurrent chemoradiotherapy in patients with head and neck carcinoma using with PET/CT.Materials and methods: 36 head and neck cancer patients who were treated in our clinic between April 2009 and April 2011 were prospectively included this study. All patients were scanned with PET/CT imaging before and after treatment and therapy response was evaluated by using FDG uptake as SUVmax. PET/CT results and biopsy that was taken from primary tumor as histopatologic assessing used for patients staging. This staging is based on AJCC 6.th edition.Results: Patients who were accepted this study were 32 male (88,9 %) and 4 female (11,1 %). The mean age of the patients was 57,5(35-77) years. Mean follow up time was 13,5 months. Pretreatment mean of SUVmax was 11. High SUVmax values (>11) predicted significantly worse survival as compared with low SUVmax (<11) (17,1 months vs 38,2 months). Survival analysis of the effect as a performans status, pretreatment SUVmax and difference SUVmax (pretreatment and posttreatment difference SUVmax) were statistically significant (p<0,001, p=0,052, p=0,074 respectively). In univariate survival analysis cumulative survival was decreased as the stage and pretreatment SUVmax increased. The cumulative survival was decreased as difference SUVmax decreased. In addition, SUVmax was increased as the stage increased. At the end of the treatment SUVmax value in early stage patients (0,002) was much more regressed than advanced stage patients (<0,001).Conclusion: In this study demonstrated that the patients with pretreatment high SUVmax had poorer prognosis. As well as stage and performance status were found to be associated with the prognosis. This study showed that pretreatment and the difference SUV max values are strong related with therapy response. Therefore, patients with higher tumor FDG uptake should be considered for a more aggressive treatment approach.Keywords: FDG-PET, head and neck cancer, therapy response