To evaluate the survival prognosis for T₁ stage nasopharyngeal carcinoma patients complicated with different stages of cervical lymph node metastasis, aiming to provide reference for optimizing the treatment plan.

Clinical data of 413 patients in non-keratinizing carcinoma and undifferentiated locally early nasopharyngeal carcinoma (T₁N_0-3M_0-1) undergoing radiotherapy alone or radiochemotherapy in Department of Radiation Oncology of our hospital from January 2014 to December 2019 were retrospectively analyzed. The survival analyses were performed with Kaplan-Meier method and statistically compared using the log-rank test.

Of all patients, 291 were male, and 122 were female (aged from 9 to 78 years old) with a median age of 51 years old. All patients were diagnosed with T₁N_0-3M_0-1 nasopharyngeal carcinoma. In the TNM stage grouping system, 48(11.6%) patients were classified as stage Ⅰ (T₁N₀M₀), 158(38.2%) cases of stage Ⅱ(T₁N₁M₀), 162(39.2%) cases of stage Ⅲ(T₁N₂M₀), and 45(10.9%) cases of stage Ⅳ_A to Ⅳ_B(T₁N₃M₀/T₁N_xM₁). Eight patients (1.9%) with stage Ⅳ_B had metastasis at presentation. The lymph node positivity rate of all patients reached up to 88.1%. Seven patients received three-dimensional conformal radiotherapy, 371 cases of intensity-modulated radiotherapy and 35 cases of volumetric-modulated arc therapy. The 5-year overall survival rate was (95.9±1.2)% and with 100% for T₁N₀M₀ patients, (99.2±0.8)% for T₁N₁M₀ patients, (95.1±2.2)% for T₁N₂M₀ patients and (87.9±6.6)% for T₁N₃M₀ patients, respectively. Primary distant metastasis and N₃ stage were significantly correlated with poor prognosis (both P<0.05). The most common long-term side effect of radiotherapy was xerostomia with an incidence rate of 18.6%(17.9% for grade 1 toxicity), followed by hearing damage and tooth discomfort. Only 2 patients developed Grade Ⅲ toxic reactions, manifested as complete hearing loss.

Although T₁ nasopharyngeal carcinoma patients have a high propensity of cervical node metastasis, favorable clinical prognosis can be obtained after radiotherapy alone. Moreover, the long-term side effects under precision radiation exert no severe effect upon the quality of life of patients.

Nasopharyngeal neoplasm/three-dimensional radiotherapy; Nasopharyngeal neoplasm/radiochemotherapy; Side effect