title: Simulating demand for innovative radiotherapies: an illustrative model based on carbon ion and proton radiotherapy.
abstract: OBJECTIVE
  Innovative therapies are not only characterized by major uncertainties regarding clinical benefit and cost but also the expected recruitment of patients. An original model was developed to simulate patient recruitment to a costly particle therapy by varying layout of the facility and patient referral (one vs. several countries) and by weighting the treated indication by the expected benefit of particle therapy.
  
  
  METHODS
  A multi-step probabilistic spatial model was used to allocate patients to the optimal treatment strategy and facility taking into account the estimated therapeutic gain from the new therapy for each tumour type, the geographical accessibility of the facilities and patient preference. Recruitment was simulated under different assumptions relating to the demand and supply.
  
  
  RESULTS
  Extending the recruitment area, reducing treatment capacity, equipping all treatment rooms with a carbon ion gantry and inclusion of proton protocols in carbon ion facilities led to an increased proportion of indications with the highest expected benefit. Assuming the existence of a competing carbon ions facility, lower values of therapeutic gain, and a greater unwillingness of patients to travel for treatment increased the proportion of indications with low expected benefit.
  
  
  CONCLUSIONS
  Modelling patient recruitment may aid decision-making when planning new and expensive treatments.
authors.affiliation: Department of Radiation Oncology, Centre Léon Bérard, Lyon, France. pommier@lyon.fnclcc.fr
authors.forename: Pascal
authors.initials: P
authors.lastname: Pommier
authors.forename: Yolande
authors.initials: Y
authors.lastname: Lievens
authors.forename: Fabien
authors.initials: F
authors.lastname: Feschet
authors.forename: Josep M
authors.initials: JM
authors.lastname: Borras
authors.forename: Marie Hélène
authors.initials: MH
authors.lastname: Baron
authors.forename: Anastasiya
authors.initials: A
authors.lastname: Shtiliyanova
authors.forename: Madelon
authors.initials: M
authors.lastname: Pijls-Johannesma
mesh_terms: D002244:Carbon / Q000627:therapeutic use*; D003198:Computer Simulation; D003661:Decision Support Techniques; D006801:Humans; D007477:Ions / Q000627:therapeutic use; D061766:Proton Therapy; D018787:Radiation Oncology / Q000191:economics; D011878:Radiotherapy / Q000706:statistics & numerical data*
chemical_list: D007477:Ions; D002244:Carbon