title: Intensity-modulated radiation therapy for head and neck cancer: systematic review and meta-analysis.
abstract: OBJECTIVE
  Intensity-modulated radiation therapy (IMRT) provides the possibility of dose-escalation with better normal tissue sparing. This study was performed to assess whether IMRT can improve clinical outcomes when compared with two-dimensional (2D-RT) or three-dimensional conformal radiation therapy (3D-CRT) in patients with head and neck cancer.
  
  
  METHODS
  Only prospective phase III randomized trials comparing IMRT with 2D-RT or 3D-CRT were eligible. Combined surgery and/or chemotherapy were allowed. Two authors independently selected and assessed the studies regarding eligibility criteria and risk of bias.
  
  
  RESULTS
  Five studies were selected. A total of 871 patients were randomly assigned for 2D-RT or 3D-CRT (437), versus IMRT (434). Most patients presented with nasopharyngeal cancers (82%), and stages III/IV (62.1%). Three studies were classified as having unclear risk and two as high risk of bias. A significant overall benefit in favor of IMRT was found (hazard ratio - HR=0.76; 95% CI: 0.66, 0.87; p<0.0001) regarding xerostomia scores grade 2-4, with similar loco-regional control and overall survival.
  
  
  CONCLUSIONS
  IMRT reduces the incidence of grade 2-4 xerostomia in patients with head and neck cancers without compromising loco-regional control and overall survival.
authors: Radiation Oncology Department, Hospital Sírio-Libanês, Brazil; Radiation Oncology Department, Instituto do Câncer de São Paulo (ICESP), Brazil. Electronic address: gnmarta@uol.com.br.
authors: Gustavo Nader
authors: GN
authors: Marta
authors: Brazilian Cochrane Center and Discipline of Emergency Medicine and Evidence-Based Medicine, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), Brazil. Electronic address: v.silva@ymail.com.
authors: Valter
authors: V
authors: Silva
authors: Radiation Oncology Department, Hospital Sírio-Libanês, Brazil; Radiation Oncology Department, Faculdade de Medicina da Universidade de São Paulo, Brazil. Electronic address: heloisa-carvalho@uol.com.br.
authors: Heloisa
authors: H
authors: de Andrade Carvalho
authors: Radiation Oncology Department, Hospital Sírio-Libanês, Brazil. Electronic address: fer.freire@ig.com.br.
authors: Fernando Freire
authors: FF
authors: de Arruda
authors: Radiation Oncology Department, Hospital Sírio-Libanês, Brazil. Electronic address: samir.hanna@hsl.org.br.
authors: Samir Abdallah
authors: SA
authors: Hanna
authors: Radiation Oncology Department, Hospital Sírio-Libanês, Brazil. Electronic address: rafagadia@yahoo.com.br.
authors: Rafael
authors: R
authors: Gadia
authors: Radiation Oncology Department, Hospital Sírio-Libanês, Brazil. Electronic address: jluis@hsl.org.br.
authors: João Luis Fernandes
authors: JL
authors: da Silva
authors: Radiation Oncology Department, Hospital Sírio-Libanês, Brazil. Electronic address: sf.correa@uol.com.br.
authors: Sebastião Francisco Miranda
authors: SF
authors: Correa
authors: Radiation Oncology Department, Hospital Sírio-Libanês, Brazil. Electronic address: cevitabr@yahoo.com.br.
authors: Carlos Eduardo Cintra
authors: CE
authors: Vita Abreu
authors: Brazilian Cochrane Center and Discipline of Emergency Medicine and Evidence-Based Medicine, Universidade Federal de São Paulo - Escola Paulista de Medicina (UNIFESP-EPM), Brazil. Electronic address: rachelriera@hotmail.com.
authors: Rachel
authors: R
authors: Riera
mesh_terms: D017326:Clinical Trials, Phase III as Topic; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D011446:Prospective Studies; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D016032:Randomized Controlled Trials as Topic
keywords: Head and neck cancer; Intensity-modulated radiation therapy; Three-dimensional conformal radiation therapy; Two-dimensional