Magnetic Resonance-Guided High-Dose Brachytherapy (Short-Range Radiation Therapy) for Prostate Cancer

This study will evaluate the use of magnetic resonance imaging (MRI) for guiding placement of hollow needles into the prostate gland for delivering internal radiation therapy to patients with prostate cancer. Prostate cancer is often treated with a combination of external beam radiation therapy and brachytherapy (internal radiation delivered close to the tumor). This study will determine whether MRI is more accurate in guiding needle placement than ultrasound, which is currently used for this purpose. Patients will have one brachytherapy treatment followed by 5 weeks of external beam treatments and a second brachytherapy. Patients 18 years of age and older with prostate cancer that has not spread to the bone may be eligible for this study. Candidates will be screened with a physical examination, blood and urine tests, and a bone scan. To plan for radiation therapy, patients will have standard computed tomography (CT) and MRI scans of the pelvis and prostate. In addition, CT and MRI scans will be done to determine if the prostate is in a good position for brachytherapy. For these scans, patients will have an enema and a tube will be placed in the rectum. They will then lie still on their side for about 45 minutes during the scan. Patients who have blood in their urine will also undergo cystoscopy. This is an examination of the bladder using a small camera that is advanced through the penis into the bladder. Patients are given an antibiotic for 2 days before the brachytherapy and on the morning of the procedure. Before the test, they have a small enema and are given medicines through the vein and into the spine for relaxation and to decrease any discomfort. (The test is done under general anesthesia for patients who require it.) The patient is moved on a stretcher into the MRI scanner and a catheter is inserted into the bladder through the penis. The bladder is filled with water and a tube is placed in the rectum. With the help of a plastic guide placed against the