A prospective, multicentric clinical study of intensity modulated radiotherapy in the treatment of nasopharyngeal carcinoma / 中华放射肿瘤学杂志

ABSTRACT

Objective To evaluate the treatment efficacy,toxicities and prognostic factors of nasopharyngeal carcinoma ( NPC ) treated with intensity modulated radiation oncology ( IMRT ).Methods Between January 2006 and August 2008,300 patients with pathologically diagnosed NPC from 6 center received IMRT.The number of patients with stage Ⅰ,Ⅱ,Ⅲ and Ⅳa+b disease (UICC/AJCC 2002 staging system) were 6,45,141 and 108,respectively.The prescription doses were as follows70-74 Gy/30f toplanning target volume of primary nasopharynx tumor ( PTVRλ),68-70 Gy/30f to planning target volume of positive lymphnode (ptvnd),60-64 Gy/30f to higher risk region (PTV1),50-54 Gy/30f to lower risk region (PTV2).Patients with stage Ⅲ and Ⅳa+b disease also received cisplatin-based chemotherapy.Cox method was used for Multivariate analysis.ResultsThe follow-up rate was 99.7％.The 4-year rate of local control,regional control,metastasis-free survival (DMFS),disease-free survival (DFS) and overall survival (OS) was 94.0％,95.5％,87.4％,80.8％,86.1％,respectively.Mucositis was the most severe acute toxicity,with 18.0％grade 1,48.7％grade 2,33.3％grade 3.No patient suffered from grade 4mucositis.Xerostomia was the most common late toxicity,with 12.0％ grade 0,75.7％ grade 1,12.3％grade 2.No grade 3-4 xerostomia was observed.There were 18,15 and 42 patients failed in local,regional and distant metastasis,respectively.Multivariate analysis showed that N stage was the only prognostic factor for OS (x2 =5.17,P=0.023),DMFS (x2 =6.91,P=0.009) and DFS (x2 =8.15,P=0.004) in these patients.ConclusionsIMRT can improve the treatment efficacy of NPC.The acute and late toxicities were tolerated.Distant metastasis becomes the main treatment failure.N stage is a significant prognostic factors.