title: Megavoltage quality control, resources and demand: a pragmatic review.
abstract: OBJECTIVE
  Satisfactory radiotherapy treatment requires quality control (QC) of the equipment as well as patient-specific checks. Increased complexity and extended use of equipment plus greater demand for complex treatment has brought pressure on QC resources. The benefits of integrating patient-specific checks and QC and the efficient use of resources is examined.
  
  
  METHODS
  A non-linear model for the probability of undetected machine failure is proposed which enables the comparative efficiency of resource to be assessed. Benefits of adopting an integrated view of patient-specific and treatment machine QC is considered, considering performance tolerance levels in the context of measurement uncertainty and patient-specific tolerances.
  
  
  RESULTS
  Essential, machine-only QC is identified. A realistic approach to equipment-only QC is identified for 70% efficient use of resources and a relationship established to determine resource required for a QC programme. Integration of patient-specific and equipment QC is shown to half the resource required for equipment QC.
  
  
  CONCLUSIONS
  Increasing benefit from QC requires greater resource, working at lower efficiency. A pragmatic approach is having guaranteed checks supplemented with additional, non-guaranteed checks performed within an integrated approach to machine- and patient-specific QC, bearing in mind the occasions when machine-only QC is essential.
  
  
  CONCLUSIONS
  The work reveals on a quantitative basis a rational approach to accommodating the QC requirements for safe and effective treatment.
authors: 1 MACS-Quality Control Provider, Hinckley, UK.
authors: John A
authors: JA
authors: Mills
authors: 2 Radiotherapy Physics Department, Raigmore Hospital, Inverness, UK.
authors: Steven J
authors: SJ
authors: Colligan
mesh_terms: D006295:Health Resources / Q000706:statistics & numerical data*; D006801:Humans; D011336:Probability; D011785:Quality Assurance, Health Care / Q000706:statistics & numerical data*; D011786:Quality Control; D011829:Radiation Dosage; D011878:Radiotherapy / Q000295:instrumentation* / Q000592:standards*