title: Utility of daily image guidance with intensity-modulated radiotherapy for tumors of the base of skull.
abstract: BACKGROUND
  This study was carried out to report our experience using intensity-modulated radiotherapy (IMRT) with daily image-guided radiotherapy (IGRT) for tumors involving the base of skull.
  
  
  METHODS
  In all, 100 patients were prospectively treated with IMRT to a median dose of 64 Gy (range, 45-70 Gy). Daily helical megavoltage computed tomography (MVCT) scans were obtained as part of an IGRT registration protocol for patient alignment.
  
  
  RESULTS
  The 2-year local-regional control was 91%. A total of 3295 daily MVCT scans were obtained. The mean shift to account for interfraction motion was 1.18 ± 1.75 mm, 1.81 ± 1.34 mm, and 1.33 ± 1.19 mm for the medial-lateral (ML), superior-inferior (SI), and anterior-posterior (AP) directions, respectively. Pretreatment shifts of >3 mm occurred in 10%, 26%, and 18%, in the ML, SI, and AP directions, respectively.
  
  
  CONCLUSIONS
  The feasibility and efficacy of daily IGRT as a complement to IMRT for skull base were demonstrated.
authors: Department of Radiation Oncology, University of California Davis Cancer Center, Sacramento, California, USA. allen.chen@ucdmc.ucdavis.edu
authors: Allen M
authors: AM
authors: Chen
authors: Suzan
authors: S
authors: Cheng
authors: D Gregory
authors: DG
authors: Farwell
authors: Quang
authors: Q
authors: Luu
authors: Paul J
authors: PJ
authors: Donald
authors: James
authors: J
authors: Boggan
authors: Stephen
authors: S
authors: Franklin
authors: James A
authors: JA
authors: Purdy
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005240:Feasibility Studies; D006801:Humans; D008875:Middle Aged; D056888:Patient Positioning; D011446:Prospective Studies; D015641:Radiography, Interventional; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated; D019292:Skull Base Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000532:radiotherapy*; D036542:Tomography, Spiral Computed