CT-validation of Ultrasound Based Planning for High Dose Rate (HDR) Prostate Brachytherapy Using Vitesse

High Dose Rate (HDR)Prostate Brachytherapy With Vitesse tm

High Dose Rate (HDR) temporary prostate brachytherapy offers a precise form of dose escalation for prostate cancer. Needles are placed, the position is confirmed and treatment is delivered. Previously High Dose Rate prostate brachytherapy was performed under TransRectal UltraSound (TRUS) guidance but planned with Computed Tomography (CT) imaging which introduced a source of error through needle displacement while transporting and repositioning patient. Recently Varian has introduced a one-step procedure where both implant and planning are based on UltraSound imaging and performed without patient repositioning. This planning system is approved by Health Canada and is commercially available.

This study will use High Dose Rate brachytherapy to treat 20 men. Treatment will be planned with TransRectal UltraSound and validated using Computed Tomography imaging.

Twenty men with intermediate risk prostate cancer, suitable for the combination of external beam radiotherapy and High Dose Rate brachytherapy will be entered in this study. High Dose Rate brachytherapy will be performed using TransRectal UltraSound guidance and then planned using both cone-beam Computed Tomography and TransRectal UltraSound. Planning by Computed Tomography is to check the reliability and reproducibility of UltraSound imaging to correctly identify the needle positions. Correct needle localization is essential because this is the basis for determining source dwell positions, dose calculation and dose optimization.

Inclusion Criteria:

1. Patients must have histologically proven adenocarcinoma of the prostate.
2. Patients must have intermediate risk prostate cancer. (Clinical stage ≤ T2c, Gleason score = 7 and initial prostate specific antigen (iPSA) ≤ 20, or Gleason score ≤ 6 and iPSA > 10 and ≤ 20.
3. Patients must be fit for general or spinal anaesthetic.
4. Patients must have an estimated life expectancy of at least 10 years.
5. Patients must have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 - 2.
6. Patients must have no contraindications to interstitial prostate brachytherapy.
7. Patients on coumadin therapy must be able to stop therapy safely for at least 7 days.

Exclusion Criteria:

• Men not able to fully understand the trial and the informed consent document
• Men suffering from claustrophobia and unable to have a Computed Tomography scan
• Men not wishing to have a cone-beam Computed Tomography scan following the insertion of the High Dose Rate brachytherapy needles to verify the accuracy of the treatment plan
• Men who cannot safely discontinue blood thinners for a few days.