Simulation of MRI-guided transurethral conformal 3-D ultrasound therapy of the prostate

Mathieu Burtnyk, Rajiv Chopra, Michael Bronskill

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The capability of MRI to measure spatial heating patterns during therapy delivery with ultrasound makes adaptive thermal therapy possible. Active feedback provided by MR thermometry enables on-line adjustment of the treatment to compensate for tissue/perfusion changes during heating. The feasibility of performing 3-D conformal thermal therapy of the entire prostate gland with a multi-element transurethral ultrasound heating applicator was considered in this study. The major challenge was using MR temperature feedback to adjust simultaneously the device's rate of rotation and the power and frequency of multiple independent ultrasound transducers, to shape the region of thermal damage to the prostate gland in all spatial dimensions while sparing surrounding tissues from damage. The 3-D Bioheat Transfer Equation was used to model the ultrasound therapy using manually segmented MRI prostate geometries from 20 prostate cancer patients. Average prostate dimensions (±SD) were: length: 37.8±7.2 mm, width: 47.1±5.5 mm, height: 28.9±5.7 mm. Typical treatments of the entire prostate volume take less than 30 min. Results from various treatment strategies were compared by calculating the percentage volume of under- and over-treated tissue and the potential thermal damage incurred by important adjacent anatomical structures using "dose- effect" curves. Visualization tools were developed to investigate patient-specific prostate and periprostatic anatomy, as well as the simulated coagulated volumes in 3-D, enabling evaluation of individual patient outcomes. These simulations also enabled the investigation of the number and size of transducer segments required for accurate treatment delivery. In general, the under-treated fraction can be maintained below 1% of the prostate volume, but the over-treated fraction can range up to 15%, emphasizing the importance of accurate location of sensitive adjacent structures.

Original languageEnglish (US)
Title of host publication6th International Symposium on Therapeutic Ultrasound
Pages413-419
Number of pages7
DOIs
StatePublished - Sep 24 2007
Event6TH INTERNATIONAL SYMPOSIUM ON THERAPEUTIC ULTRASOUND - Oxford, United Kingdom
Duration: Aug 30 2007Sep 2 2007

Publication series

NameAIP Conference Proceedings
Volume911
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616

Other

Other6TH INTERNATIONAL SYMPOSIUM ON THERAPEUTIC ULTRASOUND
CountryUnited Kingdom
CityOxford
Period8/30/079/2/07

Keywords

  • Control
  • MRI
  • Prostate
  • Thermal therapy
  • Thermometry
  • Transurethral
  • Ultrasound

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Simulation of MRI-guided transurethral conformal 3-D ultrasound therapy of the prostate'. Together they form a unique fingerprint.

  • Cite this

    Burtnyk, M., Chopra, R., & Bronskill, M. (2007). Simulation of MRI-guided transurethral conformal 3-D ultrasound therapy of the prostate. In 6th International Symposium on Therapeutic Ultrasound (pp. 413-419). (AIP Conference Proceedings; Vol. 911). https://doi.org/10.1063/1.2744306