title: Evolution of treatment for nasopharyngeal cancer--success and setback in the intensity-modulated radiotherapy era.
abstract: OBJECTIVE
  To assess the therapeutic gains and setbacks as we evolved from the 2-dimensional radiotherapy (2DRT) to conformal 3-dimensional (3DRT) and to intensity-modulated (IMRT) era.
  
  
  METHODS
  1593 consecutive patients from 1994 to 2010 were retrospectively analyzed. Evolving changes in the different era included advances in staging investigation, radiotherapy technique, dose escalation, and use of chemotherapy.
  
  
  RESULTS
  The 3DRT era achieved significant improvement in local failure-free rate (L-FFR), disease-specific survival (DSS) and overall survival (OS). Neurological damage and bone/soft tissue necrosis were significantly reduced. However, the improvement in distant failure-free rate (D-FFR) was insignificant, and more hearing impairment occurred due to chemotherapy. Significantly higher D-FFR was achieved in the IMRT era, but L-FFR did not show further improvement. 5-Year DSS increased from 78% in the 2DRT, to 81% in the 3DRT, and 85% in the IMRT era, while the corresponding neurological toxicity rate decreased from 7.4% to 3.5% and 1.8%.
  
  
  CONCLUSIONS
  Significant improvement in survival and reduction of serious toxicity was achieved as we evolved from 2DRT to 3DRT and IMRT era; the therapeutic ratio for all T-categories improved with more conformal techniques. Improvements in tumor control were attributed not only to advances in RT technique, but also to better imaging and increasing use of potent chemotherapy. However, it should also be noted that hearing impairment significantly increased due to chemotherapy, L-FFR reached a plateau in the 3DRT era, and it is worrisome that the result for T4 remained unsatisfactory. Besides exploring for more potent chemotherapy and innovative methods, the guideline on dose constraint should be re-visited to optimize the therapeutic ratio.
authors.affiliation: Clinical Oncology Center, University of Hong Kong-Shenzhen Hospital, Hong Kong. Electronic address: annelee@hku-szh.org.
authors.forename: Anne W M
authors.initials: AW
authors.lastname: Lee
authors.affiliation: Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong.
authors.forename: Wai Tong
authors.initials: WT
authors.lastname: Ng
authors.affiliation: Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong.
authors.forename: Lucy L K
authors.initials: LL
authors.lastname: Chan
authors.affiliation: Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong.
authors.forename: Wai Man
authors.initials: WM
authors.lastname: Hung
authors.affiliation: Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong.
authors.forename: Connie C C
authors.initials: CC
authors.lastname: Chan
authors.affiliation: Clinical Oncology Center, University of Hong Kong-Shenzhen Hospital, Hong Kong.
authors.forename: Henry C K
authors.initials: HC
authors.lastname: Sze
authors.affiliation: Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong.
authors.forename: Oscar S H
authors.initials: OS
authors.lastname: Chan
authors.affiliation: Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong.
authors.forename: Amy T Y
authors.initials: AT
authors.lastname: Chang
authors.affiliation: Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong.
authors.forename: Rebecca M W
authors.initials: RM
authors.lastname: Yeung
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects; D012189:Retrospective Studies
keywords: Chemotherapy; Efficacy; Late toxicity; Nasopharyngeal carcinoma; Radiotherapy