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Improving Assessment (and Ultimately Outcomes) of Permanent Prostate Implant Therapy


filter terms:
  • prostate
  • prostate cancer
    • Sizes of these terms reflect their relevance to your search.

    • Purpose

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      Permanent prostate implants are a type of radiation therapy in which a high dose of radiation is delivered to cancerous tissue by many small radioactive "seeds". Studies of early-stage prostate cancer patients treated in this way and followed for 10 - 12 years indicate a cure rate of about 80%. This result is similar to surgery and other forms of radiotherapy, but comes with fewer side effects and greater convenience for the patient.
      Further studies show that the radiation dose delivered is the most important factor in achieving a cure. At present this dose is estimated by a computer, using a computed tomography (CT) scan of the patient and a simple calculation method. The dose estimate is not as accurate as it could be, however, because the precise extent of the prostate is hard to determine from the CT scan, and the calculation method does not make use of information about patient body tissues. The researchers propose to eliminate these inaccuracies by using magnetic resonance imaging (MRI) to identify the prostate gland and by developing an improved dose calculation algorithm that includes information about patient tissues. This new approach will allow physicians to assess implant quality with greater certainty, improve their implant technique, and ultimately increase the cure rate to as much as 95%.


      status: recruiting
      conditions: Prostate Cancer
      interventions: Permanent prostate implant
      phase: N/A
      study type: Interventional
      study design: Treatment, Non-Randomized, Open Label, Uncontrolled, Single Group Assignment, Efficacy Study
      official title: Improving Assessment (and Ultimately Outcomes) of Permanent Prostate Implant Therapy

    • Further study details (as provided by Alberta Cancer Board)

      primary outcome measures:

      • implant dose coverage at 4 weeks, comparing CT and MRI versus CT alone

      secondary outcome measures:

      • implant edema at time of implant and at 2 and 4 weeks

      enrollment: 40

      study start date: April 2005

      study completion date: December 2007


      Detailed description

      This study addresses three major sources of post-implant dosimetry inaccuracy for permanent prostate implants:
      post-operative edema, prostate contour delineation, and dose calculation method. It is hypothesized that a pragmatic edema model can minimize the first uncertainty, co-registered CT + MR images the second, and an improved dose calculation algorithm the third.
      Detailed objectives are to:

      • measure and model the effects of edema on dosimetry;
      • evaluate CT + MR image registration methods;
      • compare dosimetry for CT alone vs. CT + MRI using the contemporary TG-43 dose calculation method;
      • set up a Monte Carlo code that makes full use of the information in CT + MR images to perform implant dose calculations;
      • compare prostate dosimetry for the Monte Carlo vs. the simpler TG-43 method;
      • develop an analytical post-implant dose calculation algorithm for routine clinical use (Monte Carlo is too slow on a single-CPU brachytherapy planning computer); and finally
      • assess the performance of the new algorithm.
      Of the estimated 250,000 new cases of prostate cancer in North America in 2004, most are early stage disease as a consequence of PSA testing. Permanent prostate implant therapy is a major option for this group, as long-term clinical studies indicate a cure rate equal to surgery and external beam radiotherapy, but with fewer complications. By dealing with dosimetric inaccuracies, a proven treatment can reach its full potential.

    • Eligibility

      ages eligible for study:
      genders eligible for study: Male

      Criteria

      Inclusion Criteria:
      • Candidate for permanent prostate implant

      Exclusion Criteria:
      • Not ambulatory

    • Contacts and locations

      Please refer to this study by its ClinicalTrials.gov identifier: NCT00127816

      Contacts

      Ron Sloboda, PhD   780-432-8719   ron.sloboda@cancerboard.ab.ca

      Locations

      Canada , Alberta  - Cross Cancer Institute

      status: recruiting
      facility: Edmonton, Alberta, Canada, T6G 1Z2
      contact: Clinical Research Unit   780-989-8152   clinical_trials_cci@cancerboard.ab.ca
      Principal Investigator: Ron Sloboda, PhD

    • Sponsors and collaborators

      Alberta Cancer Board

      investigators: Ron Sloboda, PhD, Principal Investigator, Alberta Cancer Board

    • More information

      Other publications

      Nag S, Bice W, DeWyngaert K, Prestidge B, Stock R, Yu Y. The American Brachytherapy Society recommendations for permanent prostate brachytherapy postimplant dosimetric analysis. Int J Radiat Oncol Biol Phys. 2000 Jan 1;46(1):221-30. Review.

      Yu Y, Anderson LL, Li Z, Mellenberg DE, Nath R, Schell MC, Waterman FM, Wu A, Blasko JC. Permanent prostate seed implant brachytherapy: report of the American Association of Physicists in Medicine Task Group No. 64. Med Phys. 1999 Oct;26(10):2054-76.

      first received: August 5, 2005
      last updated: September 22, 2008
      ClinicalTrials.gov Identifier: NCT00127816
      health authority: Canada: Health Canada

    Information obtained from ClinicalTrials.gov on September 25, 2009   Link to the current ClinicalTrials.gov record.

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