Using Fiducial Markers to Aid in Prostate Cancer Radiation Treatment
Condition: Prostate Cancer; Cancer
MeSH terms: Prostatic Neoplasms
Study type: Interventional
Phase: Phase 1

Summary: 
      To effectively treat prostate cancer, doctors need an accurate view (via X-rays) of the
      prostate gland during radiation therapy. To help improve this view, doctors may insert gold
      markers called fiducials into the prostate by placing hollow gold needles through the rectum
      and moving a fiducial through each needle. The purpose of the study is to determine whether
      an MRI scan can help doctors improve their placement of these needles.

      Fifteen men will participate in this study. Patients will take the antibiotic levofloxacin
      for two days prior to the placement of the fiducials, then will have a small enema and
      another dose of the antibiotic on the morning of the procedure. After being anesthetized,
      patients will have an antenna-like tube placed into the rectum and have MRI images taken of
      the area. The doctor will then use these scans to place four fiducials into the prostate. The
      procedure will require approximately 45 minutes. Patients will be allowed to go home the same
      day of the procedure, which will be followed by a seven-week course of standard radiation
      therapy.

      Prior to their participation in this study, patients will undergo the following evaluations:
      a physical exam, blood work, urine tests, and, if appropriate, an MRI or bone scan.
    

Detailed description: 
      Effective image-guided prostate therapies require excellent visualization of the prostate and
      surrounding anatomy, such that cancerous tissue can be treated while avoiding nearby neural
      and vascular structures. As such, Magnetic Resonance Imaging is well suited for
      image-guidance because of its excellent soft tissue contrast, multiplanar capabilities, and
      the potential to yield spectral/biological tumor mapping. Despite the potential for
      MRI-guided prostate therapies, there are currently no techniques that allow for precise
      trans-rectal intraprostatic needle placement in patients.

      In this pilot study we seek to validate the accuracy and tolerability of a new system and
      technique that allows for accurate placement of needles within the prostate based upon MR
      images. The method is very similar to transrectal ultrasound guided biopsy of the prostate,
      except that it is applicable within a closed high-field MRI scanner. Four gold fiducial
      markers will be placed within the prostate under needle guidance in a series of patients with
      localized prostate cancer before external beam radiotherapy. Fifteen patients will be
      enrolled onto this study with sample size determined to obtain reasonably precise estimates
      of mean placement accuracy. The accrual period is expected to be less than a year.

      While placement of the fiducial markers has no direct therapeutic benefit for the patient,
      intraprostatic radiopaque fiducial markers (placed under ultrasound) have shown value in
      assessing daily setup errors and off-line organ motion during external beam radiation therapy
      for prostate cancer. Therefore, a secondary objective is to gain experience using these
      intraprostatic fiducial markers for daily assessment and adjustment of external radiation
      beam targeting. These markers can also be utilized to aid in CT-MRI fusion and results in
      better target delineation for treatment planning. In this way, prostate cancer patients who
      are receiving external-beam radiation therapy may benefit from participation.
    

Intervention name(s): Fiducial marker placement
Intervention type(s): Procedure
Intervention description(s): Placement of fidicual markers under MRI guidance for localization of radiaiton treatment
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Fiducial Marker; MRI; Prostate Cancer; Radiation