Article Delay Head and Neck Neoplasms Head and neck cancer Humans Incidental Findings Incidental findings Overall survival Retrospective Studies Squamous Cell Carcinoma of Head and Neck Time-to-Treatment Time-to-treatment initiation aged cancer patient cancer radiotherapy cancer survival chemoradiotherapy cohort analysis controlled study diagnostic imaging dying female head and neck squamous cell carcinoma head and neck tumor human incidental finding major clinical study male overall survival radiologist