Dual-target reduction in locally advanced nasopharyngeal carcinoma: omission of Ib/VIIb irradiation and medial boundary contraction of the CTV

The goal of this study was to maintain a high cure rate for nasopharyngeal carcinoma (NPC) while reducing the area of radiation delivered to the target volume to minimize the incidence of mucosal ulcers with a toxicity grade of 3 or above. The primary objective was to reduce the incidence of mucosal ulcers with a toxicity grade of 3 or above post-radiotherapy. Between January 2023 and March 2024, 20 eligible patients received reduced-target radiotherapy, and none withdrew from the study. Acute and late toxicity reactions and survival rates after treatment were evaluated. As of the data cutoff date (January 06, 2026), the median follow-up period was 27 months (range: 21–33 months). All patients were alive with no locoregional recurrence, except for one patient who developed femoral metastasis at 21 months post-radiotherapy. The incidence of mucosal ulcers with a toxicity grade of 3 or above, the primary endpoint of this study, was 0. No patients exhibited radiotherapy-related acute xerostomia, dermatitis, or mucositis with a toxicity grade of 3 or above. From 3 months after the end of radiotherapy to the end of follow-up, no dysphagia, subcutaneous soft tissue injury, or nasopharyngeal necrosis of any grade and no cases of grade 3 or above xerostomia or hearing impairment were observed. In carefully selected patients, this reduced-target radiotherapy strategy is anatomically and dosimetrically feasible, with a favorable short-term safety profile.