DARS optimized radiotherapy, head and neck cancer, organ and function preservation, HNSCC therapy intensification, tumor control, acute and late toxicities, treatment induced dysphagia, dysphagia and aspiration related structures, pharyngeal constrictors, glottic and supra glottic larynx, anxiety and depression, hospital anxiety, RT planning, contouring of PCs as a single organ, cricoid, superior, middle, inferior constrictors, GSL, esophagus, cricopharyngeus muscle, superior neck, thyroid cartilage, dose volume, swallowing structures, superior PC doses, correlations, mean dose to larynx, MRI, IMRT, concurrent chemotherapy with cisplatin, 60Gy for DARS, Do-IMRT, concomitant chemotherapy, Ca nasopharynx, Ca oropharynx, fractionation 200cGy/fr/day, reduce volume, ipsilateral PC