title: Automatic tracking of gold seed markers from CBCT image projections in lung and prostate radiotherapy.
abstract: OBJECTIVE
  To construct a method and software to track gold seed implants in prostate and lung patients undergoing radiotherapy using CBCT image projections.
  
  
  METHODS
  A mathematical model was developed in the MatLab (Mathworks, Natick, USA) environment which uses a combination of discreet cosine transforms and filtering to enhance several edge detection methods for identifying and tracking gold seed fiducial markers in images obtained from Varian (Varian Medical Systems, Palo Alto, USA) and Elekta (Kungstensgatan, Sweden) CBCT projections.
  
  
  RESULTS
  Organ motion was captured for 16 prostate patients and 1 lung patient.
  
  
  CONCLUSIONS
  Image enhancement and edge detection is capable of automatically tracking markers for up to 98% (Varian) and 79% (Elekta) of CBCT projections for prostate and lung markers however inclusion of excessive bony anatomy (LT and RT LAT) inhibit the ability of the model to accurate determine marker location.
authors.affiliation: Peter MacCallum Cancer Centre, Melbourne, Victoria 3002, Australia. Electronic address: christopher.gehrke@petermac.org.
authors.forename: Christopher
authors.initials: C
authors.lastname: Gehrke
authors.affiliation: Peter MacCallum Cancer Centre, Melbourne, Victoria 3002, Australia.
authors.forename: Richard
authors.initials: R
authors.lastname: Oates
authors.affiliation: Peter MacCallum Cancer Centre, Melbourne, Victoria 3002, Australia.
authors.forename: Prabhakar
authors.initials: P
authors.lastname: Ramachandran
authors.affiliation: Peter MacCallum Cancer Centre, Melbourne, Victoria 3002, Australia.
authors.forename: Hossain M
authors.initials: HM
authors.lastname: Deloar
authors.affiliation: Peter MacCallum Cancer Centre, Melbourne, Victoria 3002, Australia.
authors.forename: Suki
authors.initials: S
authors.lastname: Gill
authors.affiliation: Peter MacCallum Cancer Centre, Melbourne, Victoria 3002, Australia.
authors.forename: Tomas
authors.initials: T
authors.lastname: Kron
mesh_terms: D001331:Automation; D054893:Cone-Beam Computed Tomography / Q000592:standards*; D019583:Dose Fractionation, Radiation; D057918:Fiducial Markers; D006046:Gold; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000532:radiotherapy*; D008297:Male; D009068:Movement; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000532:radiotherapy*
chemical_list: D006046:Gold
keywords: CBCT; Image-guided radiation therapy; Motion tracking