title: Analysis and evaluation of periodic physiological organ motion in radiotherapy treatments.
abstract: OBJECTIVE
  A system for the detection, measurement and analysis of the periodic physiological organ motion during radiotherapy treatment is proposed and clinically tested in this paper.
  
  
  METHODS
  The procedure is based on the acquisition of fluoroscopic sequences, followed by an automatic detection of the movement using cross-correlations with matched filters.
  
  
  RESULTS
  The system generates a probability density function (PDF) of finding a mobile organ in a position at a certain time. The maximum path of the mobile structures can be determined to define the planning target volume (PTV) without ambiguities.
  
  
  CONCLUSIONS
  Physiological movements can be accurately included in the daily planning routine, which is not essentially modified, without needing previous patient training.
authors.affiliation: Service of Radiation Physics and Radiation Protection, Hospital Clínico Universitario de Valencia, Av. Blasco Ibañez 17, 46010 Valencia, Spain.
authors.forename: Sergio
authors.initials: S
authors.lastname: Díez
authors.forename: Javier
authors.initials: J
authors.lastname: García
authors.forename: Francisco
authors.initials: F
authors.lastname: Sendra
mesh_terms: D001331:Automation; D019583:Dose Fractionation, Radiation; D005471:Fluoroscopy; D006801:Humans; D009068:Movement; D009369:Neoplasms / Q000532:radiotherapy; D010347:Patient Care Planning; D020266:Radiotherapy, Conformal / Q000379:methods*; D012119:Respiration; D012137:Respiratory System / Q000033:anatomy & histology