117PCorrelation of MRI derived parameters and SUV uptake obtained from FDG- PET-CT with human papillomavirus status in oropharyngeal squamous cell carcinomas

Abstract Background A favorable response to (chemo) radiotherapy (CCRT) is seen in human papillomavirus (HPV)-positive OPSCC patients. Apparent diffusion coefficient (ADC) derived from MRI has shown to predict treatment response. We evaluated the correlation between clinico-demographic profile of oropharyngeal squamous cell carcinomas patients (OPSCC patients) HPV status and ADC values, SUV uptake obtained from FDG- PET-CT. Methods The study population was obtained from a historical cohort diagnosed with HPV-related OPSCC. A total of 105 OPSCC patients who had undergone molecular testing for HPV status by p16 with Immuno-histochemistry (IHC) were identified. 96 patients had pretreatment imaging (either PET-CT or MRI) and post CCRT imaging was included. Imaging was evaluated by head and neck radiologists to calculate mean ADC and SUV max. Pearson Chi- Square and ANOVA analyses were performed to evaluate the correlation. Results 26 OPSCC were HPV-positive. HPV-positive HNSCC showed significantly association with smoking, grade & stage of the tumor, T status, Response to CCRT, lymph nodes, and ADC values on follow up imaging. Conclusions In OPSCC patient’s positive HPV status correlates with follow up mean apparent diffusion coefficient. The complimentary prognostic value of post treatment apparent diffusion coefficient might be partially ascribed to patients with a positive HPV status. Further studies are reasonable to determine whether PET-CT is a useful imaging biomarker in comparison to ADC to risk-stratify patients with HPV-related OPSCC. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.