Suggestions for surveillance and radiation strategy in nasopharyngeal carcinoma treated with IMRT: Based on hazard-rate and patterns of recurrence

Abstract

ObjectiveThe study was designed to appraise the locoregional recurrence patterns using conventional two-dimensional radiotherapy (2D-RT) and intensity modulated radiation therapy (IMRT) in nasopharyngeal carcinoma (NPC) in order to better establish the scenario of the modern radiotherapy and the duration of surveillance. Materials and MethodsWe reviewed the institutional database to identify patients with pathologically confirmed, non-metastatic NPC who completed radical 2D-RT or IMRT at our center from 2000 to 2011. We collected data on clinicopathologic features, treatments and outcomes. Statistical analyses were performed using SPSS 20.0 or STATASE 14.0. ResultsThe median follow-up was 60.1 months. Of 2315 patients, 1289 (53%) were treated with 2D-RT and 1026 (47%) with IMRT. IMRT group achieved better locoregional control rate, with the 5-year locoregional relapse-free survival (LRRFS) were 84.9% and 87.7% among patients received 2D-RT and IMRT, respectively (P = 0.050). IMRT was superior to 2D technique in terms of local relapse-free survival (LRFS) (88.4% vs 91.1%, P = 0.047) and the advantage was only significant in T3-4 subgroup (81.6% vs 90.2%, P = 0.000). Similar neck control rates were observed using different RT techniques. And the recurrence time appeared to be postponed by IMRT, with peaks accounting for the year 1.5 and year 3–4 compared to which was predominant at the first two years using 2D-RT in nature. ConclusionsIMRT provided an improved LRRFS in overall stage and LRFS in advanced T stage for NPC compared with 2D-RT. Annual hazard of recurrence also changed with RT techniques.