Tumor factors associated with in‐field failure for nasopharyngeal carcinoma after intensity‐modulated radiotherapy
Xixi Liu, Bian Wu, Jing Huang, You Qin, Zhanjie Zhang, Liangliang Shi, Xiaohua Hong, Qian Ding, Gang Peng, Kunyu Yang
Abstract
BACKGROUND: To identify the tumor factors of in-field failure for nasopharyngeal carcinoma (NPC) in the intensity-modulated radiotherapy (IMRT) era. METHODS: Patterns of recurrence were classified as in-field, marginal, and out-field failures. Multivariate analyses with the Cox proportional hazards model were used to identify tumor-related factors of in-field failure. RESULTS: A total of 1039 patients with NPC received IMRT from 2012 to 2019 and 75 developed recurrences, with 88.0% (66/75) considered as having in-field failures. Multivariate analysis showed that pretreatment gross tumor volume of nasopharynx ≥68.8 mL and histopathological type of nonkeratinizing differentiated carcinoma (NKDC) were the independent tumor factors of in-field local failure, while gross tumor volume of involved lymph nodes ≥19.9 mL and cervical nodal necrosis (CNN) were associated with in-field regional failure (all p < 0.05). CONCLUSIONS: In-field failure was the major pattern of recurrence in patients with NPC. Large tumor volume, NKDC, and CNN were the tumor factors associated with in-field failure.