title: Intensity-modulated radiation therapy achieves better local control compared to three-dimensional conformal radiation therapy for T4-stage nasopharyngeal carcinoma.
abstract: OBJECTIVE
  To examine the survival outcomes and late toxicity profiles of three-dimensional conformal radiation therapy (3DCRT) vs. intensity-modulated radiation therapy (IMRT) for patients with nasopharyngeal carcinoma (NPC).
  
  
  METHODS
  Three hundred and seventy-four patients with newly diagnosed, non-metastatic, NPC who were curatively treated with 3DCRT between 2004 and 2006 and 481 patients treated with IMRT between 2007 and 2009 were analyzed. Patients were categorized as having advanced-stage disease (stage III, IVA, and IVB disease; n = 709) or early-stage disease (stage I and II; n = 146). The median follow-up time was 90.3 months for patients treated with 3DCRT and 86.3 months for patients treated with IMRT.
  
  
  RESULTS
  For early-stage patients, the outcomes of IMRT vs. 3DCRT were similar considering locoregional control (LRC), distant metastasis-free survival (DMFS), and overall survival (OS). For advanced-stage patients, IMRT was associated with better LRC compared with 3DCRT (5-year LRC rate: 85.6% vs. 76.6%, respectively; p = 0.035) and OS (5-year OS rate: 82.3% vs. 71.8%, respectively; p = 0.002), whereas DMFS was similar for both treatments (5-year DMFS rate: 80.9% vs. 79.0%, respectively; p = 0.324). Furthermore, the IMRT technique was more beneficial for patients with T4 disease. Late toxicities occurred more frequently in patients treated with 3DCRT than in those treated with IMRT (grade ≥3 neck fibrosis: 6.7% vs. 3.7%, respectively, p = 0.036; radiographic temporal lobe necrosis: 10.2% vs. 4.4%, respectively, p < 0.001).
  
  
  CONCLUSIONS
  Compared with 3DCRT, IMRT offered better LRC in patients with advanced-stage non-metastatic NPC, which corresponded with better OS.
authors.affiliation: Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.|Department of Radiation Oncology, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu, Taiwan.
authors.forename: Jenny Ling-Yu
authors.initials: JL
authors.lastname: Chen
authors.affiliation: Department of Medical Imaging, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.|Department of Medical Imaging, National Taiwan University Hospital Yun-Lin Branch, Yun-Lin, Taiwan.
authors.forename: Yu-Sen
authors.initials: YS
authors.lastname: Huang
authors.affiliation: Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.|Graduate Institute of Oncology, National Taiwan University, Taipei, Taiwan.
authors.forename: Sung-Hsin
authors.initials: SH
authors.lastname: Kuo
authors.affiliation: Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Ruey-Long
authors.initials: RL
authors.lastname: Hong
authors.affiliation: Department of Otolaryngology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Jenq-Yuh
authors.initials: JY
authors.lastname: Ko
authors.affiliation: Department of Otolaryngology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Pei-Jen
authors.initials: PJ
authors.lastname: Lou
authors.affiliation: Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Chun-Wei
authors.initials: CW
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D002648:Child; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects; D016896:Treatment Outcome; D055815:Young Adult
keywords: conformal radiation therapy; intensity-modulated radiation therapy; late toxicities; nasopharyngeal carcinoma; survival outcomes