title: How does intensity-modulated radiotherapy versus conventional two-dimensional radiotherapy influence the treatment results in nasopharyngeal carcinoma patients?
abstract: OBJECTIVE
  To compare the results of intensity-modulated radiotherapy (IMRT) with those of two-dimensional conventional radiotherapy (2D-CRT) in the treatment of patients with nasopharyngeal carcinoma (NPC).
  
  
  METHODS
  A retrospective review of data from 1,276 patients with biopsy-proven, nonmetastatic NPC was performed. All patients had undergone magnetic resonance imaging and were staged according to the sixth edition of the American Joint Committee on Cancer staging criteria. Radiotherapy was the primary treatment for all patients.
  
  
  RESULTS
  Of the 1,276 patients, 512 were treated with IMRT and 764 with 2D-CRT. The 5-year actuarial local relapse-free survival (LRFS), the nodal relapse-free survival (NRFS), the distant metastasis-free survival (DMFS), and the disease-free survival (DFS) rates were 92.7%, 97.0%, 84.0%, and 75.9%, respectively, for the IMRT group, and 86.8%, 95.5%, 82.6%, and 71.4%, respectively, for the 2D-CRT group. In stage T1 patients, improvement of LRFS in the IMRT group was even significantly higher than in the 2D-CRT group (100% vs. 94.4%; p = 0.016). A trend of improvement of DFS was observed in the IMRT group compared with the 2D-CRT group but without reaching statistical significance. NRFS and DMFS rates were similar in the two groups.
  
  
  CONCLUSIONS
  A greater improvement of treatment results with IMRT than with 2D-CRT was demonstrated primarily by achieving a higher local tumor control rate in NPC patients, especially in the early T stage patients. The goal of better control of both local failure in advanced, nonmetastatic NPC patients and of distant failure should be addressed in future studies.
authors.affiliation: State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Cancer Center, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Shu-Zhen
authors.initials: SZ
authors.lastname: Lai
authors.forename: Wen-Fei
authors.initials: WF
authors.lastname: Li
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Chen
authors.forename: Li-Zhi
authors.initials: LZ
authors.lastname: Liu
authors.forename: Ying
authors.initials: Y
authors.lastname: Sun
authors.forename: Ai-Hua
authors.initials: AH
authors.lastname: Lin
authors.forename: Meng-Zhong
authors.initials: MZ
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D009367:Neoplasm Staging / Q000379:methods; D011878:Radiotherapy / Q000379:methods; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome; D047368:Tumor Burden; D055815:Young Adult