Evaluation of a new transperineal ultrasound probe for inter-fraction image-guidance for definitive and post-operative prostate cancer radiotherapy

Phys Med. 2016 Mar;32(3):499-505. doi: 10.1016/j.ejmp.2016.01.481. Epub 2016 Feb 2.


Purpose: 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.

Keywords: IGRT; Post-prostatectomy; Prostate; Transperineal ultrasound.

MeSH terms

  • Cohort Studies
  • Combined Modality Therapy
  • Humans
  • Image Processing, Computer-Assisted
  • Male
  • Prostatectomy
  • Prostatic Neoplasms / diagnostic imaging*
  • Prostatic Neoplasms / radiotherapy*
  • Prostatic Neoplasms / surgery
  • Radiotherapy Planning, Computer-Assisted / instrumentation
  • Radiotherapy Planning, Computer-Assisted / methods
  • Ultrasonography, Interventional / instrumentation*
  • Ultrasonography, Interventional / methods