title: Clinical outcomes and patterns of failure after intensity-modulated radiotherapy for nasopharyngeal carcinoma.
abstract: OBJECTIVE
  To study and report the clinical outcomes and patterns of failure after intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC).
  
  
  METHODS
  The treatment outcomes of NPC patients treated with IMRT at Pamela Youde Nethersole Eastern Hospital between 2005 and 2007 were reviewed. The location and extent of locoregional failures were transferred to the pretreatment planning computed tomography for dosimetry analysis. Statistical analyses were performed on dose coverage and locoregional failures.
  
  
  RESULTS
  A total of 193 NPC patients were analyzed; 93% had Stage III/IV disease. Median follow-up was 30 months. Overall disease failure (at any site) developed in 35 patients. Among these, there were 23 distant metastases, 16 local failures, and 9 regional failures. Four of the locoregional failures were marginal. Dose conformity with IMRT was excellent. Patients with at least 66.5 Gy to their target volumes had significantly less locoregional failure. The 2-year local progression-free, regional progression-free, distant metastasis-free, and overall survival rates were 95%, 96%, 90%, and 92%, respectively.
  
  
  CONCLUSIONS
  Intensity-modulated radiotherapy provides excellent locoregional control for NPC. Distant metastasis remains the most difficult challenge, and more effective systemic agents should be explored for patients presenting with advanced locoregional diseases.
authors.affiliation: Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong. ngwt1@ha.org.hk
authors.forename: Wai Tong
authors.initials: WT
authors.lastname: Ng
authors.forename: Michael C H
authors.initials: MC
authors.lastname: Lee
authors.forename: Wai Man
authors.initials: WM
authors.lastname: Hung
authors.forename: Cheuk Wai
authors.initials: CW
authors.lastname: Choi
authors.forename: Kin Chung
authors.initials: KC
authors.lastname: Lee
authors.forename: Oscar S H
authors.initials: OS
authors.lastname: Chan
authors.forename: Anne W M
authors.initials: AW
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002277:Carcinoma; D017024:Chemotherapy, Adjuvant; D002945:Cisplatin / Q000008:administration & dosage; D018572:Disease-Free Survival; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy / Q000556:secondary; D058958:Organs at Risk / Q000033:anatomy & histology; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods; D012074:Remission Induction; D016896:Treatment Outcome; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D002945:Cisplatin; D005472:Fluorouracil