Effect of interrupted time during intensity modulated radiation therapy on survival outcomes in patients with nasopharyngeal cancer

Abstract

ObjectiveTo evaluate the influence of interrupted time (IT) during intensity-modulated radiotherapy (IMRT) on survival outcomes in patients with nasopharyngeal cancer (NPC).Materials and methods515 NPC patients receiving IMRT between January 2007 and December 2011 were retrospectively reviewed. The association of IT with loco-regional failure-free survival (LRFS), progression free survival (PFS) and overall survival (OS) was assessed by univariate and multivariate analysis. The Kaplan–Meier methodology was used for survival analyses and the differences among groups were assessed by the log-rank test. The Cox model was used for evaluating the prognostic factors for LRFS, PFS, and OS.ResultsThe 3-year PFS and OS analysis revealed significant difference between patients with a IT >4 days and those with a IT ≤4 days (72.1% vs 81.9%, p <0.05; 80.8% vs 87.9%, p <0.05). Age (≥44 years vs <44 years), T classification, N classification, and IT (>4 days vs ≤4 days) were independent prognostic factors for PFS and OS, respectively (p <0.05). Only N classification acted as the prognostic factor for LRFS (p <0.05).ConclusionThe IT of more than 4 days during IMRT may affect survival outcomes of NPC patients. We should minimize the interruption of radiotherapy caused by any reason as much as possible.

Efficacy of Different Chemotherapy Regimens in Patients with Locally Advanced Synchronous Esophageal and Head/Neck Squamous Cell Carcinoma Receiving Curative Concurrent Chemoradiotherapy

“…Several studies have confirmed the relationship between interruption of CCRT and survival outcome [27][28][29]. Xu et al showed that interruptions of more than four days during radiotherapy were associated with worse progression-free survival and OS in patients with nasopharyngeal cancer [29]. Another study reported by Krusun demonstrated that worse OS was found in the interrupted group compared to the uninterrupted group of patients with cervical cancer who underwent CCRT [27].…”

“…Our study showed that interruption of the CCRT is a poor prognostic factor for patients with synchronous ESCC/HNSCC who received CCRT with a curative intent. Several studies have confirmed the relationship between interruption of CCRT and survival outcome [27][28][29]. Xu et al showed that interruptions of more than four days during radiotherapy were associated with worse progression-free survival and OS in patients with nasopharyngeal cancer [29].…”

Survival impact of treatment‐related time intervals in nasopharyngeal carcinoma in the United States

“…Currently, there is a lack of consensus concerning what is considered as prolonged RT or interrupted RT, and the methods to quantify this are heterogeneous. For example, some authors have examined total RT duration, whereas others have examined the number of continuous days that RT was interrupted . Furthermore, the existing published data largely consists of retrospective data that is small in sample size .…”

“…For example, some authors have examined total RT duration, whereas others have examined the number of continuous days that RT was interrupted . Furthermore, the existing published data largely consists of retrospective data that is small in sample size . To our knowledge, there is only one published data in a large prospective cohort investigating this question, which is by Yao et al In this study of 447 patients, Yao et al found that RT interruption was significantly associated with locoregional failure survival (LRFS) in the multivariable analysis (HR = 9.64, 95% CI, 4.10–22.65), but RT interruption was not significantly associated with OS in the multivariable model.…”

“…Recent studies have investigated whether several treatment‐related time intervals (TRTIs), such as time to radiation (TTR) and radiation duration (RTd), would impact survival in NPC patients. The results have been equivocal, with some studies finding a correlation between treatment interruptions/TTR with survival and others finding no correlation …”