title: Evaluation of trends in the use of intensity-modulated radiotherapy for head and neck cancer from 2000 through 2005: socioeconomic disparity and geographic variation in a large population-based cohort.
abstract: BACKGROUND
  The current study was conducted to evaluate trends in utilization of intensity-modulated radiotherapy (IMRT) for head and neck cancer (HNC).
  
  
  METHODS
  Identified were 5487 patients from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database with a diagnosis of HNC (aged>or=65 years) between 2000 and 2005, who received any type of radiotherapy (RT). Multivariate logistic regression analyses were performed to assess the influence of patient, tumor, treatment, and sociodemographic characteristics on receipt of IMRT versus conventional radiotherapy techniques.
  
  
  RESULTS
  Overall, 21.3% of patients in the cohort received IMRT as the technique of irradiation. The use of IMRT increased significantly, with 1.3% of patients receiving it in 2000 compared with 46.1% in 2005 (P<.0001 for trend). Patients treated with RT in 2005 were 68 times more likely to receive IMRT than those treated in 2000. There was significant geographic variation observed in use of IMRT, ranging from 11.3% of cases in Kentucky to 40.4% of cases in Hawaii. Patients in the census tracks comprising the lowest quartile for socioeconomic status were 33% less likely to receive IMRT than patients in the highest quartile, even when adjusting for geographic area and year of diagnosis.
  
  
  CONCLUSIONS
  The use of IMRT has rapidly become widespread for the delivery of RT for patients with HNC. However, there was significant geographic variation noted in the utilization of IMRT. Patients in census tracks comprising the lowest socioeconomic quartile were less likely to receive IMRT than their more affluent counterparts.
authors.affiliation: Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA. aguadagnolo@gmail.com
authors.forename: B Ashleigh
authors.initials: BA
authors.lastname: Guadagnolo
authors.forename: Chih-Chin
authors.initials: CC
authors.lastname: Liu
authors.forename: Janice N
authors.initials: JN
authors.lastname: Cormier
authors.forename: Xianglin L
authors.initials: XL
authors.lastname: Du
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D054625:Healthcare Disparities; D006801:Humans; D008297:Male; D050397:Radiotherapy, Intensity-Modulated / Q000706:statistics & numerical data / Q000639:trends*; D012959:Socioeconomic Factors; D014481:United States