The impact of human papilloma virus status on the prediction of head and neck cancer chemoradiotherapy outcomes using the pre-treatment apparent diffusion coefficient.

Abstract

OBJECTIVE\nTo 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 pre-treatment quantitative diffusion-weighted magnetic resonance imaging (DW-MRI).\n\n\nMETHODS\nFollowing 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 (ROIs) (volume, largest area, core) at the primary tumour (n = 57) and largest pathological node (n = 59) were placed to analyse ADCmean and ADCmin. Unpaired t-test or Mann-Whitney test evaluated the impact of HPV OPC status and clinical parameters on their prediction of post-CRT 2\u2009year loco-regional and disease-free survival (LRFS and DFS). Multivariate logistic regression compared significant variables with 2\u2009year outcomes.\n\n\nRESULTS\nOn univariate analysis of all participants, the primary tumour area ADCmean was predictive of 2\u2009year 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\u2009year DFS in the HPV OPC subgroup (p = 0.21-0.68). Amongst participants without 2\u2009year disease-free survival, HPV-OPC was found to have much lower primary tumour ADCmean values than other HNSCC.\n\n\nCONCLUSION\nKnowledge of HPV OPC status is required in order to determine the impact of the pre-treatment ADC values on post-CRT outcomes in HNSCC.\n\n\nADVANCES IN KNOWLEDGE\nPre-treatment ADCmean and ADCmin values acquired using different ROI methods are not predictive of 2\u2009year survival outcomes in HPV OPC.