title: Evaluation of a new transperineal ultrasound probe for inter-fraction image-guidance for definitive and post-operative prostate cancer radiotherapy.
abstract: OBJECTIVE
  The aim of this study was to evaluate a new system based on transperineal ultrasound (TP-US) acquisitions for prostate and post-prostatectomy pre-treatment positioning by comparing this device to cone-beam computed tomography (CBCT).
  
  
  METHODS
  The differences between CBCT/CT and TP-US/TP-US registrations were analyzed on 427 and 453 sessions for 13 prostate and 14 post-prostatectomy patients, respectively. The inter-operator variability (IOV) of the registration process, and the impact and variability of the probe pressure were also evaluated.
  
  
  RESULTS
  CBCT and TP-US shift agreements at ± 5 mm were 76.6%, 95.1%, 96.3% and 90.3%, 85.0%, 97.6% in anterior-posterior, superior-inferior and left-right directions, for prostate and post-prostatectomy patients, respectively. IOV values were similar between the 2 modalities. Displacements above 5 mm due to strong pressures were observed on both localizations, but such pressures were rarely reproduced during treatment courses.
  
  
  CONCLUSIONS
  High concordance between CBCT/CT and TP-US/TP-US localization of prostates or prostatic beds was found in this study. TP-US based prepositioning is a feasible method to ensure accurate treatment delivery, and represents an attractive alternative to invasive and/or irradiating imaging modalities.
authors: CREATIS, INSA, Université de Lyon, CNRS UMR5220, Inserm U1044, Lyon F-69622, France.
authors: Marie
authors: M
authors: Fargier-Voiron
authors: CREATIS, INSA, Université de Lyon, CNRS UMR5220, Inserm U1044, Lyon F-69622, France.
authors: Benoît
authors: B
authors: Presles
authors: Léon Bérard Cancer Center, University of Lyon, Lyon F-69373, France.
authors: Pascal
authors: P
authors: Pommier
authors: Léon Bérard Cancer Center, University of Lyon, Lyon F-69373, France.
authors: Alexandre
authors: A
authors: Munoz
authors: CREATIS, INSA, Université de Lyon, CNRS UMR5220, Inserm U1044, Lyon F-69622, France.
authors: Simon
authors: S
authors: Rit
authors: CREATIS, INSA, Université de Lyon, CNRS UMR5220, Inserm U1044, Lyon F-69622, France; Léon Bérard Cancer Center, University of Lyon, Lyon F-69373, France.
authors: David
authors: D
authors: Sarrut
authors: CREATIS, INSA, Université de Lyon, CNRS UMR5220, Inserm U1044, Lyon F-69622, France; Léon Bérard Cancer Center, University of Lyon, Lyon F-69373, France. Electronic address: marie-claude.biston@lyon.unicancer.fr.
authors: Marie-Claude
authors: MC
authors: Biston
mesh_terms: D015331:Cohort Studies; D003131:Combined Modality Therapy; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy* / Q000601:surgery; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D018084:Ultrasonography, Interventional / Q000295:instrumentation* / Q000379:methods
keywords: IGRT; Post-prostatectomy; Prostate; Transperineal ultrasound