title: Intensity-modulated radiation therapy versus 2D-RT or 3D-CRT for the treatment of nasopharyngeal carcinoma: A systematic review and meta-analysis.
abstract: OBJECTIVE
  To compare clinical treatment outcomes and late toxicities of intensity-modulated radiation therapy (IMRT) with those obtained with two-dimensional radiation therapy (2D-RT) or three-dimensional conformal radiation therapy (3D-CRT) in nasopharyngeal carcinoma (NPC).
  
  
  METHODS
  We searched all the eligible studies from the Cochrane Library, PubMed, Medline, and Embase. The meta-analysis was performed to compare odds ratio (OR) for overall survival (OS), tumor local control (LC), and late toxicities.
  
  
  RESULTS
  A total of eight studies met the criteria to perform a meta-analysis including 3570 participants, with 1541 patients in the IMRT group and 2029 in the 2D-RT or 3D-CRT group. The IMRT group was associated with a better 5-year overall survival (OR=1.51; 95% confidence interval (CI) 1.23-1.87; p=0.0001), and tumor local control (LC) (OR=1.94; 95% CI 1.53-2.46; p<0.00001). According to CTCAE v3.0 (Common Terminology Criteria for Adverse Events) and RTOG/EORTC (Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer), the incidence of late xerostomia in those who received IMRT was significantly lower than that of the control group (OR=0.18; 95% CI, 0.07-0.46; p=0.0004). In addition, the radiation-induced chronic toxicities rate of trismus and temporal lobe neuropathy (TLN) were also significantly lower in the IMRT group than in the control group (OR=0.18; 95% CI 0.04-0.83; p=0.03; OR=0.44; 95% CI 0.28-0.69; p=0.0003, respectively).
  
  
  CONCLUSIONS
  This systematic review and meta-analysis demonstrated that IMRT mayobtain a better antitumor effect, and significantly decrease the incidence of radiation-induced late toxicities in patients with NPC.
authors: The Department of Medical Oncology, Cancer Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.
authors: Binglan
authors: B
authors: Zhang
authors: The Department of Medical Oncology, Cancer Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.
authors: Zeming
authors: Z
authors: Mo
authors: The Department of Medical Oncology, Cancer Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.
authors: Wei
authors: W
authors: Du
authors: The First People's Hospital of Longquanyi District, Chengdu, China.
authors: Yan
authors: Y
authors: Wang
authors: The Department of Medical Oncology, Cancer Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China. Electronic address: liuleihx@gmail.com.
authors: Lei
authors: L
authors: Liu
authors: The Department of Medical Oncology, Cancer Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.
authors: Yuquan
authors: Y
authors: Wei
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000401:mortality / Q000532:radiotherapy; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D015996:Survival Rate; D016896:Treatment Outcome
keywords: Intensity-modulated radiation therapy; Meta-analysis; Nasopharyngeal carcinoma; Three-dimensional conformal radiation; Two-dimensional