Intensity-modulated radiation therapy (IMRT) has gradually replaced two-dimensional radiation therapy as it offers improved target conformity. Xerostomia is still the most common side effect of radiotherapy in patients with NPC treated with IMRT. Most stimulated saliva is secreted by the parotid glands (PGs), while the submandibular glands (SMGs) produce most of the unstimulated saliva and mucins, which may influence the degree of a dry mouth sensation.There are still differences in the understanding of nasopharyngeal cancer experts at home and abroad on the delineation of clinical target volumes., suitable criteria for elective irradiation of neck level Ib need to be re-evaluated.Therefore, we conducted a retrospective study to assess the feasibility of recommendation to level Ib in the International Guideline for Delineation of Clinical Target Volumes.
The purpose of this study was to evaluate its rationality in real-world data and provide clinical evidence for the refinement of nodal CTV delineation in nasopharyngeal carcinoma(NPC).