title: Understanding variations in the use of hypofractionated radiotherapy and its specific indications for breast cancer: A mixed-methods study.
abstract: Radiation oncology guidelines favour hypofractionated whole-breast radiotherapy (HWBRT) over more conventional schemes in the conservative treatment of breast cancer, but its adoption still varies in clinical practice. This study assessed the patterns of HWBRT adoption in Catalonia (Spain).
  
  
  
  We used a mixed-methods approach based on an explanatory sequential design, first collecting and analysing quantitative data on HWBRT use (>2.5Gy per fraction) in 11 public radiotherapy centres (2005-2015) and then performing 25 semi-structured interviews with all department heads and reference radiation oncologist/s.
  
  
  
  Of the 34,859 patients fulfiling the study criteria over the study period, just 12% were hypofractionated, reaching a percentage of 29% in 2015 (p<0.001). Our analysis showed a narrowing age gap between patients receiving conventional fractionation and hypofractionation in centres leading adoption. However, there were important differences in clinicians' interpretation of evidence (e.g. regarding the perceived risk of long-term toxicity) and selection of patients for specific indications, both within and between departments.
  
  
  
  Differences observed in the rate of adoption of HWBRT could not be tackled only using a rational, evidence-based approach. Factors related to the management of radiotherapy departments play a major role in the diffusion of therapeutic strategies.
authors.affiliation: Catalonian Cancer Strategy, Department of Health, Barcelona, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Prades
authors.affiliation: Department of Radiation Oncology, Parc de Salut Mar. University Pompeu Fabra (UPF). Hospital del Mar Medical Research Institute (IMIM). Barcelona, Spain.
authors.forename: Manel
authors.initials: M
authors.lastname: Algara
authors.affiliation: Catalonian Cancer Strategy, Department of Health, Barcelona, Spain.
authors.forename: Josep A
authors.initials: JA
authors.lastname: Espinàs
authors.affiliation: Department of Radiation Oncology, Hospital Clínic, Barcelona, Spain.
authors.forename: Blanca
authors.initials: B
authors.lastname: Farrús
authors.affiliation: Department of Radiation Oncology, Hospital Universitari Sant Joan de Reus, Spain; University of Rovira and Virgili (URV), Reus, Spain.
authors.forename: Meritxell
authors.initials: M
authors.lastname: Arenas
authors.affiliation: Department of Radiation Oncology, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
authors.forename: Victoria
authors.initials: V
authors.lastname: Reyes
authors.affiliation: Department of Radiation Oncology, Hospital Arnau de Vilanova, Lleida, Spain.
authors.forename: Virginia
authors.initials: V
authors.lastname: García-Reglero
authors.affiliation: Department of Radiation Oncology, Institut Oncològic del Vallés, Hospital Universitari General de Catalunya-Grupo Quirónsalud, Terrassa, Spain.
authors.forename: Maria Josep
authors.initials: MJ
authors.lastname: Cambra
authors.affiliation: Department of Radiation Oncology, Institut Oncològic del Vallés, Consorci Sanitari de Terrassa, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Rubio
authors.affiliation: Dept. of Radiation Oncology, Catalan Institut of Oncology, University Hospital Dr. Josep Trueta, Girona, Spain.
authors.forename: Lluis
authors.initials: L
authors.lastname: Anglada
authors.affiliation: University of Barcelona (IDIBELL), Spain; Department of Radiation Oncology, Catalan Institute of Oncology, L'Hospitalet, Spain.
authors.forename: Arantxa
authors.initials: A
authors.lastname: Eraso
authors.affiliation: Department of Radiation Oncology, Hospital Plató, Barcelona, Spain.
authors.forename: Agustí
authors.initials: A
authors.lastname: Pedro
authors.affiliation: Department of Radiation Oncology, Sant Pau Hospital, Barcelona, Spain.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Fuentes-Raspall
authors.affiliation: Department of Radiation Oncology, ICO Badalona. Hospital Universitari Germans Trias i Pujol; Badalona, Spain.
authors.forename: Victòria
authors.initials: V
authors.lastname: Tuset
authors.affiliation: Catalonian Cancer Strategy, Department of Health, Barcelona, Spain.
authors.forename: Judit
authors.initials: J
authors.lastname: Solà
authors.affiliation: Catalonian Cancer Strategy, Department of Health, Barcelona, Spain; University of Barcelona (IDIBELL), Spain. Electronic address: jmborras@iconcologia.net.
authors.forename: Josep M
authors.initials: JM
authors.lastname: Borras
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008875:Middle Aged; D000069473:Radiation Dose Hypofractionation; D013030:Spain; D016896:Treatment Outcome
keywords: Breast neoplasms; Dose hypofractionation; Mixed-methods; Radiation oncology