[Clinical classification, staging and treatment strategy of radionecrosis of the nasopharynx and skull base].

To establish a staging system for guiding clinical treatment and prognostic risk assessment by retrospectively analyzing the cases with radionecrosis of the nasopharynx and skull base （RNSB） after radiotherapy for nasopharyngeal carcinoma. A total of 86 cases of RNSB from January 2019 to December 2022 visited Department of Otorhinolaryngology Head and Neck, the People's Hospital of Guangxi Zhuang Autonomous Region. Seventeen patients gave up the treatment, and 69 patients who underwent treatment were included for analysis. By analyzing the results of electronic nasopharyngolaryngoscopy combined with magnetic resonance （MR）, CT, and other imaging examinations, a staging system for RNSB was proposed. The relationship between the staging system and the surgical effectiveness and clinical prognosis was further analyzed. According to the severity and extent of destruction of soft tissue, bone, and the adjacent neurovascular structures, the RNSB was categorized into closed type （=5） and open type （=64）, of which the open type was subdivided into five types: type Ⅰ（=4）, type Ⅱ（=6）, type Ⅲ（=39, of which 21 cases were type Ⅲa and 18 cases were type Ⅲb）, type Ⅳ（=12）, and type Ⅴ（=8）. The clinical stage of RNSB were classified based on nasopharyngolaryngoscopy and imaging examinations, receiving the second course of radiotherapy or not, the involvement of the infection site, the extent of bone destruction, the degree of internal carotid artery involvement, and the degree of brain tissue necrosis: stageⅠ（1-2 scores）, 11 cases at stageⅡ（3-4 scores）, 24 cases at stage Ⅲ（5-6 scores）, and 30 cases at stage Ⅳ（ ≥ 7 scores or more）. Twenty-two patients chose conservative treatment （2 patients at stage Ⅰ, 3 patients at stage Ⅱ, 7 patients at stage Ⅲ, and 10 patients at stage Ⅳ）. Forty-seven patients chose nasal endoscopic surgical treatment （2 patients at stage Ⅰ, 8 patients at stage Ⅱ, 17 patients at stage Ⅲ, and 20 patients at stage Ⅳ）, of which 16 cases had received free mucosal flap and/or stented septum mucosal flap repair. Patients at stages Ⅰ, Ⅱ, and Ⅲ achieved satisfactory efficacy after surgical treatment. In addition, higher clinical stage was found to correlate with the worse prognosis and higher incidence of perioperative complications, which included failure of healing because of surgical site infection, cerebrospinal fluid nasal leakage, progressive osteonecrosis, nasopharyngeal hemorrhage, and death. The staging system proposed in our study can be used for early detection of RNSB during regular follow-up, and is also valuable for clinical treatment guidance and prognosis assessment.