title: Optimal location of radiation therapy centers with respect to geographic access.
abstract: OBJECTIVE
  To develop a framework with which to evaluate locations of radiation therapy (RT) centers in a region based on geographic access.
  
  
  METHODS
  Patient records were obtained for all external beam radiation therapy started in 2011 for the province of British Columbia, Canada. Two metrics of geographic access were defined. The primary analysis was percentage of patients (coverage) within a 90-minute drive from an RT center (C90), and the secondary analysis was the average drive time (ADT) to an RT center. An integer programming model was developed to determine optimal center locations, catchment areas, and capacity required under different scenarios.
  
  
  RESULTS
  Records consisted of 11,096 courses of radiation corresponding to 161,616 fractions. Baseline geographic access was estimated at 102.5 minutes ADT (each way, per fraction) and 75.9% C90. Adding 2 and 3 new centers increased C90 to 88% and 92%, respectively, and decreased ADT by between 43% and 61%, respectively. A scenario in which RT was provided in every potential location that could support at least 1 fully utilized linear accelerator resulted in 35.3 minutes' ADT and 93.6% C90.
  
  
  CONCLUSIONS
  The proposed framework and model provide a data-driven means to quantitatively evaluate alternative configurations of a regional RT system. Results suggest that the choice of location for future centers can significantly improve geographic access to RT.
authors.affiliation: Radiotherapy Department, Vancouver Centre, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
authors.forename: Pablo
authors.initials: P
authors.lastname: Santibáñez
authors.affiliation: Radiotherapy Department, Vancouver Centre, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: Gaudet
authors.affiliation: Radiotherapy Department, Vancouver Centre, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
authors.forename: John
authors.initials: J
authors.lastname: French
authors.affiliation: Radiotherapy Department, Vancouver Centre, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
authors.forename: Emma
authors.initials: E
authors.lastname: Liu
authors.affiliation: Radiotherapy Department, Vancouver Centre, British Columbia Cancer Agency, Vancouver, British Columbia, Canada. Electronic address: styldesl@bccancer.bc.ca.
authors.forename: Scott
authors.initials: S
authors.lastname: Tyldesley
mesh_terms: D001334:Automobile Driving / Q000706:statistics & numerical data*; D001955:British Columbia; D002173:Cancer Care Facilities / Q000458:organization & administration / Q000706:statistics & numerical data*; D002391:Catchment Area, Health / Q000706:statistics & numerical data*; D019583:Dose Fractionation, Radiation; D006297:Health Services Accessibility / Q000458:organization & administration / Q000706:statistics & numerical data*; D006801:Humans; D008962:Models, Theoretical; D009369:Neoplasms / Q000532:radiotherapy*; D010315:Particle Accelerators / Q000706:statistics & numerical data / Q000600:supply & distribution; D011365:Professional Practice Location / Q000706:statistics & numerical data*; D013997:Time Factors