51 PET Scan Assessment of Response 12 Weeks Post Radical Radiotherapy in Oropharynx Head and Neck Cancer: The Impact of P16 Status

•NPV of post-treatment PET scan is excellent regardless of p16 status.•PPV of post-treatment PET scan is significantly lower in those with p16+ disease.•PET scans completed ≤12 weeks in p16+ disease have inferior regional specificity.•CMR on post treatment PET predicts for significantly improved overall survival.