Quantitative measures for evaluation of ultrasound therapies of the prostate

Ilya Kobelevskiy, Mathieu Burtnyk, Michael Bronskill, Rajiv Chopra

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

1 Scopus citations

Abstract

Development of non-invasive techniques for prostate cancer treatment requires implementation of quantitative measures for evaluation of the treatment results. In this paper. we introduce measures that estimate spatial targeting accuracy and potential thermal damage to the structures surrounding the prostate. The measures were developed for the technique of treating prostate cancer with a transurethral ultrasound heating applicators guided by active MR temperature feedback. Variations of ultrasound element length and related MR imaging parameters such as MR slice thickness and update time were investigated by performing numerical simulations of the treatment on a database of ten patient prostate geometries segmented from clinical MR images. Susceptibility of each parameter configuration to uncertainty in MR temperature measurements was studied by adding noise to the temperature measurements. Gaussian noise with zero mean and standard deviation of 0, 1, 3 and 5°C was used to model different levels of uncertainty in MR temperature measurements. Results of simulations for each parameter configuration were averaged over the database of the ten prostate patient geometries studied. Results have shown that for update time of 5 seconds both 3- and 5-mm elements achieve appropriate performance for temperature uncertainty up to 3°C, while temperature uncertainty of 5°C leads to noticeable reduction in spatial accuracy and increased risk of damaging rectal wall. Ten-mm elements lacked spatial accuracy and had higher risk of damaging rectal wall compared to 3- and 5-mm elements, but were less sensitive to the level of temperature uncertainty. The effect of changing update time was studied for 5-mm elements. Simulations showed that update time had minor effects on all aspects of treatment for temperature uncertainty of 0°C and 1°C, while temperature uncertainties of 3°C and 5°C led to reduced spatial accuracy, increased potential damage to the rectal wall, and longer treatment times for update time above 5 seconds. Overall evaluation of results suggested that 5-mm elements showed best performance under physically reachable MR imaging parameters.

Original languageEnglish (US)
Title of host publication9th International Symposium on Therapeutic Ultrasound - ISTU 2009
Pages229-233
Number of pages5
DOIs
StatePublished - Mar 30 2010
Event9th International Symposium on Therapeutic Ultrasound, ISTU 2009 - Aix-en-Provence, France
Duration: Sep 24 2009Sep 26 2009

Publication series

NameAIP Conference Proceedings
Volume1215
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616

Other

Other9th International Symposium on Therapeutic Ultrasound, ISTU 2009
CountryFrance
CityAix-en-Provence
Period9/24/099/26/09

Keywords

  • MRI-guided
  • Prostate
  • Quantitative measure
  • Treatment evaluation
  • Ultrasound therapy

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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  • Cite this

    Kobelevskiy, I., Burtnyk, M., Bronskill, M., & Chopra, R. (2010). Quantitative measures for evaluation of ultrasound therapies of the prostate. In 9th International Symposium on Therapeutic Ultrasound - ISTU 2009 (pp. 229-233). (AIP Conference Proceedings; Vol. 1215). https://doi.org/10.1063/1.3367148