The impact of Human Papilloma Virus status on the prediction of head and neck cancer chemoradiotherapy outcomes using the pre-treatment apparent diffusion coefficient

Objective: To determine the impact of Human Papilloma Virus (HPV) oropharyngeal cancer (OPC) status on the prediction of head and neck squamous cell cancer (HNSCC) chemoradiotherapy (CRT) outcomes with pretreatment quantitative diffusion-weighted magnetic resonance imaging (DW-MRI). Methods: Following ethical approval, 65 participants (53 male, age 59.9 +/- 7.86) underwent pre-treatment DW-MRI in this prospective cohort observational study. There were 46 HPV OPC and 19 other HNSCC cases with Stage III/IV HNSCC. Regions of interest (ROls) (volume, largest area, core) at the primary tumour (n = 57) and largest pathological node (n = 59) were placed to analyse ADC(mean) and ADC(min). Unpaired t-test or Mann-Whitney test evaluated the impact of HPV OPC status and clinical parameters on their prediction of post-CRT 2year locoregional and disease-free survival (LRFS and DFS). Multivariate logistic regression compared significant variables with 2 year outcomes. Results: On univariate analysis of all participants, the primary tumour area ADC(mean) was predictive of 2 year LRFS (p = 0.04). However, only the HPV OPC diagnosis (LFRS p = 0.03; DFS p = 0.02) predicted outcomes on multivariate analysis. None of the pre-treatment ADC values were predictive of 2 year DFS in the HPV OPC subgroup (p = 0.21-0.68). Amongst participants without 2 year disease-free survival, HPV-OPC was found to have much lower primary tumour ADC(mean) values than other HNSCC. Conclusion: Knowledge of HPV OPC status is required in order to determine the impact of the pre-treatment ADC values on post-CRT outcomes in HNSCC. Advances in knowledge: Pre-treatment ADC(mean) and ADC(min) values acquired using different ROI methods are not predictive of 2 year survival outcomes in HPV OPC.

Automated summary

The study looked at the impact of HPV OPC status on predicting outcomes of HNSCC CRT with pretreatment DW-MRI, finding that HPV OPC diagnosis was a significant predictor of 2-year survival outcomes, while pretreatment ADC values did not predict survival in the HPV OPC subgroup.