title: Analysis of late toxicity in nasopharyngeal carcinoma patients treated with intensity modulated radiation therapy.
abstract: OBJECTIVE
  To observe the late toxicities in nasopharyngeal carcinoma (NPC) patients who achieved long-term survival after intensity modulated radiation therapy (IMRT).
  
  
  METHODS
  208 untreated NPC patients who received IMRT and survived more than five years with locoregional disease control and no metastasis were evaluated in this study. The prescription dose to the gross target volume of nasopharynx (GTVnx), positive neck lymph nodes (GTVnd), clinical target volume 1 (CTV1) and 2 (CTV2) was 68Gy/30f, 60-66Gy/30f, 60 Gy/30f and 54Gy/30f, respectively. The nasopharynx and upper neck targets were irradiated using IMRT, and the lower neck and supraclavicular fossae targets were irradiated using the half-beam technique with conventional irradiation. The late toxicities were evaluated according to the LENT/SOMA criteria of 1995.
  
  
  RESULTS
  The median follow-up time was 78 months (60-96 months). The occurrence rates of cervical subcutaneous fibrosis, hearing loss, skin dystrophy, xerostomia, trismus, temporal lobe injury, cranial nerve damage, cataract, and brain stem injury induced by radiotherapy were 89.9%, 67.8%, 47.6%, 40.9%, 7.21%, 4.33%, 2.88%, 1.44%, and 0.48%, respectively. No spinal cord injury and mandible damage were found. Grade 3-4 late injuries were observed as follows: 1 (0.48%) skin dystrophy, 4 (1.92%) cervical subcutaneous fibrosis, 2 (0.96%) hearing loss, 2 (0.96%) cranial nerve palsy, and 1 (0.48%) temporal lobe necrosis. No grade 3-4 late injuries occurred in parotid, temporomandibular joints and eyes. Xerostomia decreased gradually over time and then showed only slight changes after 4 years. The change in the incisor distance stabilised by 1 year after RT, however, the incidence of hearing loss, skin dystrophy, subcutaneous fibrosis and nervous system injuries increased over time after RT.
  
  
  CONCLUSIONS
  The late injuries in most NPC patients who had long-term survivals after IMRT are alleviated. Within the 5 years of follow-up, we found xerostomia decreased gradually; The change in the incisor distance stabilised by 1 year after RT; while hearing loss, nervous system injuries increased over time after RT.
authors.affiliation: Department of Radiotherapy, Beijing Chaoyang Hospital, Affiliated to Capital Medical University, Beijing, 100020, PR China. yingjiezheng@139.com.
authors.forename: YingJie
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in Southern China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, PR China. hanfei@sysucc.org.cn.
authors.forename: Fei
authors.initials: F
authors.lastname: Han
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in Southern China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, PR China. xiaoww@sysucc.org.cn.
authors.forename: WeiWei
authors.initials: W
authors.lastname: Xiao
authors.affiliation: Department of Nasopharyngeal Carcinoma, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, PR China. xiangyq@sysucc.org.cn.
authors.forename: YanQun
authors.initials: Y
authors.lastname: Xiang
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in Southern China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, PR China. lulx@sysucc.org.cn.
authors.forename: LiXia
authors.initials: L
authors.lastname: Lu
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in Southern China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, PR China. dengxw@sysucc.org.cn.
authors.forename: XiaoWu
authors.initials: X
authors.lastname: Deng
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in Southern China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, PR China. cuisirgz@sohu.com.
authors.forename: NianJi
authors.initials: N
authors.lastname: Cui
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in Southern China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, PR China. zhaochong@sysucc.org.cn.
authors.forename: Chong
authors.initials: C
authors.lastname: Zhao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002277:Carcinoma; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D009367:Neoplasm Staging; D011379:Prognosis; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D013997:Time Factors; D014987:Xerostomia / Q000175:diagnosis / Q000209:etiology*; D055815:Young Adult