title: Design of quality assurance for sonographic prostate brachytherapy needle guides.
abstract: OBJECTIVE
  Needles are guided to their proper anatomic locations in sonographically guided percutaneous prostate brachytherapy by a mechanical system (template). A quality assurance procedure has been designed to test this template's alignment with the needle position overlay grid displayed in the sonographic image.
  
  
  METHODS
  A mechanical arrangement was designed to position the needles properly with respect to the prostate probe's transducer in a liquid-filled test tank. Two liquids were tested: tap water and an ethylene glycol mixture with an acoustic velocity of 1540 m/s. Needle images with the superposed grid were analyzed for needle placement accuracy.
  
  
  RESULTS
  The tap water produced misregistration of the needle images. The ethylene glycol mixture yielded images of vertical and horizontal needle positions accurate to 0.3 and 1 mm, respectively. Also, the importance of selecting the lowest possible equipment echo amplitude dynamic range in these tests was shown.
  
  
  CONCLUSIONS
  This quality assurance test with the ethylene glycol mixture will permit accurate alignment of the brachytherapy needle position overlay grid for each separate transrectal probe used.
authors.affiliation: Department of Radiology, Wayne State University School of Medicine, Detroit, Michigan, USA.
authors.forename: Albert
authors.initials: A
authors.lastname: Goldstein
authors.forename: Mark
authors.initials: M
authors.lastname: Yudelev
authors.forename: Renu K
authors.initials: RK
authors.lastname: Sharma
authors.forename: Elayne
authors.initials: E
authors.lastname: Arterbery
mesh_terms: D001918:Brachytherapy / Q000295:instrumentation*; D019855:Ethylene Glycol; D006801:Humans; D008297:Male; D009339:Needles; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011786:Quality Control; D014159:Transducers
chemical_list: D019855:Ethylene Glycol