title: Mild toxicity and favorable prognosis of high-dose and extended involved-field intensity-modulated radiotherapy for patients with early-stage nasal NK/T-cell lymphoma.
abstract: OBJECTIVE
  The value of intensity-modulated radiotherapy (IMRT) for early-stage nasal NK/T-cell lymphoma has not been previously reported. The aim of the present study was to assess the dosimetric parameters, toxicity, and treatment outcomes of patients with nasal NK/T-cell lymphoma.
  
  
  METHODS
  Between 2003 and 2008, 42 patients with early-stage nasal NK/T-cell lymphoma underwent definitive high-dose and extended involved-field IMRT with or without combination chemotherapy. The median radiation dose to the primary tumor was 50 Gy. The dose-volume histograms of the target volume and critical normal structures were evaluated in all patients. The locoregional control, overall survival, and progression-free survival were calculated using the Kaplan-Meier method.
  
  
  RESULTS
  The average mean dose delivered to the planning target volume was 55.5 Gy. Only 1.3% and 2.5% of the planning target volume received <90% and 95% of the prescribed dose, respectively, indicating excellent planning target volume coverage. The mean dose and average dose to the parotid glands was 15 Gy and 14 Gy, respectively. With a median follow-up time of 27 months, the 2-year locoregional control, overall survival, and progression-free survivalrate was 93%, 78%, and 74%, respectively. No Grade 4 or 5 acute or late toxicity was reported.
  
  
  CONCLUSIONS
  High-dose and extended involved-field IMRT for patients with early-stage nasal NK/T-cell lymphoma showed favorable locoregional control, overall survival, and progression-free survival, with mild toxicity. The dose constraints of IMRT for the parotid glands can be limited to <20 Gy in these patients.
authors.affiliation: Department of Radiation Oncology, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Ye-Xiong
authors.initials: YX
authors.lastname: Li
authors.forename: Wei-Hu
authors.initials: WH
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Jin
authors.forename: Jian-Rong
authors.initials: JR
authors.lastname: Dai
authors.forename: Shu-Lian
authors.initials: SL
authors.lastname: Wang
authors.forename: Yue-Ping
authors.initials: YP
authors.lastname: Liu
authors.forename: Yong-Wen
authors.initials: YW
authors.lastname: Song
authors.forename: Zhao-Yang
authors.initials: ZY
authors.lastname: Wang
authors.forename: Qing-Feng
authors.initials: QF
authors.lastname: Liu
authors.forename: Hui
authors.initials: H
authors.lastname: Fang
authors.forename: Shu-Nan
authors.initials: SN
authors.lastname: Qi
authors.forename: Xin-Fan
authors.initials: XF
authors.lastname: Liu
authors.forename: Zi-Hao
authors.initials: ZH
authors.lastname: Yu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D054391:Lymphoma, Extranodal NK-T-Cell / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009669:Nose Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D058958:Organs at Risk / Q000000981:diagnostic imaging / Q000528:radiation effects; D010306:Parotid Gland / Q000000981:diagnostic imaging / Q000528:radiation effects; D011379:Prognosis; D011859:Radiography; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects* / Q000379:methods; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult