Salvage Prostatectomy After Radiotherapy: Whole-Mount Histopathological Validation for Tumor-Targeted Salvage HDR Brachytherapy
Two hundred and nineteen thousand new cases of prostate cancer have been projected in the
Unites States for 2007, with external beam radiotherapy (EBRT) constituting the mainstay of
local therapy for an increasing proportion of newly diagnosed patients. Despite
improvements in the delivery and reduction in associated toxicity of external beam
radiotherapy, local persistence or recurrence of disease remains prevalent in 25-51% of
patients. Local disease after EBRT is a risk factor for subsequent metastatic progression
and prostate cancer-specific mortality, and is a cause of morbidity including hematuria,
obstructive uropathy, and chronic pain. Given its prevalence, and the lack of satisfactory
local salvage treatments, fear of prostate cancer recurrence has been shown to impose a
substantial burden of suffering in patients.
Stereotactic needle placement under MRI-guidance enables two critical steps in
tumor-targeted brachytherapy: 1) directly guiding brachytherapy catheters to sites of tumor
recurrence, and 2) permitting treatment planning and delivery to be based on 3D MRI images.
MRI-based HDR brachytherapy will precisely identify the location of brachytherapy catheters
relative to the target volumes and adjacent normal structures at risk of radiation injury,
obviating the need for invasive saturation (24-100) mapping biopsies.
This study will build the evidence supporting the concept of tumor-targeted salvage HDR
brachytherapy, by providing further histopathological validation of the method.
Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment
To Validate virtual dosimetry plans for tumor-targeted salvage (High-Dose-Rate) HDR brachytherapy against co-registered whole-mount prostatectomy specimens.
Patients will have follow-up assessments at 1,3 and 6 months and 1,2,3 and 5 years after surgery.
Cynthia Ménard, MD
University Health Network, Toronto
Canada: Ethics Review Committee
UHN REB 08-0350-CE