Tumor factors associated with in-field failure for nasopharyngeal carcinoma after intensity-modulated radiotherapy

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.

Automated summary

This study aims to identify tumor factors associated with in-field failure in patients with nasopharyngeal carcinoma (NPC) receiving intensity-modulated radiotherapy (IMRT). The results showed that in-field failure was the major pattern of recurrence in NPC patients. Large tumor volume, nonkeratinizing differentiated carcinoma, and cervical nodal necrosis were independent tumor factors associated with in-field failure.