title: Real-time US versus CT determination of pubic arch interference for brachytherapy.
abstract: OBJECTIVE
  Part 1, to determine whether transrectal ultrasonography (US) enables accurate determination of pubic arch interference (PAI) for prostate brachytherapy (PBT); part 2, to compare the accuracy of transrectal US with that of computed tomography (CT) for PAI determination; and part 3, to determine the cost savings of PAI determination with transrectal US versus that with CT.
  
  
  METHODS
  Part 1: The pubic arch was identified intraoperatively with transrectal US and compared with attempted needle passage (14 patients). Part 2: Planning CT with the patient supine was compared with planning transrectal US with patients in the dorsal lithotomy position (nine patients). Part 3: Cost savings were calculated for PAI determination with transrectal US versus that with CT (32 patients per group).
  
  
  RESULTS
  Part 1: Transrectal US accurately showed the pubic arch relative to the prostate. Part 2: CT resulted in PAI overestimation by 11.8 mm. Part 3: Cost savings with transrectal US were $1,465 per patient.
  
  
  CONCLUSIONS
  Transrectal US PAI determination is easily performed, intraoperatively useful, and accurate. CT can result in PAI overestimation. Reducing direct CT costs and the indirect costs of unnecessary hormonal therapy for false-positive PAI will reduce expense and improve patient care. Transrectal US should replace CT for PAI determination.
authors.affiliation: Department of Radiology, University of Rochester Medical Center, 601 Elmwood Ave, Box 648, Rochester, NY 14642, USA. john_strang@urmc.rochester.edu
authors.forename: J G
authors.initials: JG
authors.lastname: Strang
authors.forename: D J
authors.initials: DJ
authors.lastname: Rubens
authors.forename: R A
authors.initials: RA
authors.lastname: Brasacchio
authors.forename: Y
authors.initials: Y
authors.lastname: Yu
authors.forename: E M
authors.initials: EM
authors.lastname: Messing
mesh_terms: D000368:Aged; D001918:Brachytherapy; D017046:Cost Savings; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000191:economics / Q000532:radiotherapy*; D011630:Pubic Bone / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000191:economics; D014463:Ultrasonography / Q000191:economics / Q000379:methods