Skip to main content
OpenTrials
Completed

NCT Number: NCT00127816

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

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%.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Prostate Cancer Genital Diseases Genital Diseases, Male Genital Neoplasms, Male Male Urogenital Diseases Neoplasms Neoplasms by Site Prostatic Diseases Prostatic Neoplasms Urogenital Diseases Urogenital Neoplasms

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

Cross Cancer Institute

Edmonton, Alberta, T6G 1Z2, Canada

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Candidate for permanent prostate implant

Exclusion criteria

  • Not ambulatory

Treatment and study plan

Permanent prostate implant

Procedure

Primary outcomes

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

Secondary outcomes

  1. implant edema at time of implant and at 2 and 4 weeks

Sponsors and collaborators

Lead sponsor

AHS Cancer Control Alberta

Other

Collaborators

  • Cross Cancer Institute

Registry information

Important dates

Study start
2005
Primary completion
2013
Study completion
2013
First posted
Aug 9, 2005
Registry last updated
Mar 16, 2016

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.