Effectiveness of the SpaceOAR Vue System in Subjects With Prostate Cancer

Inclusion Criteria: * Age ≥ 18 years old. * Subjects must have pathologically confirmed (by routine hematoxylin and eosin (H\&E) staining) invasive adenocarcinoma of the prostate and been planning to undergo SBRT. * Subjects must have intermediate risk prostate cancer as defined by the presence of one or more of the following: * Clinical Stage T2b - T2c (AJCC 6th edition) tumor * Gleason Score 7 as determined from a biopsy taken within 9 months preceding Enrollment (randomization) * Demonstrated blood PSA levels 10-20 ng/ml as measured within 6 months preceding Enrollment (randomization) and prior to commencing androgen deprivation therapy (ADT) * Subject or authorized representative was informed of the nature of the study and provided written informed consent, approved by the appropriate Institutional Review Board (IRB)/Ethics Committee (EC) of the respective clinical site. Exclusion Criteria: * Prostate \>80 cc documented within 9 months preceding Enrollment (randomization) * Clinical stage T3 or T4 (AJCC 6th edition) tumor * Blood PSA level \>20 ng/ml as measured within 6 months preceding Enrollment (randomization) and prior to commencing androgen deprivation therapy (ADT) * Gleason Score ≥ 8 as determined from a biopsy taken within 9 months preceding Enrollment (randomization) * Subjects who had MRI evidence of gross posterior extracapsular extension (ECE) of the prostate cancer. (Note: MRI should be from within 9 months preceding Enrollment (randomization). If MRI is contraindicated, a digital rectal exam may be performed to confirm the absence of gross posterior ECE) * Subjects who had metastatic disease, other ongoing cancers which were treated during the study or subjects for whom pelvic lymph node radiotherapy was planned. * Subjects with any prior invasive malignancy (except non-melanomatous skin cancer) unless the subject had been disease free for a minimum of 3 years. * History of prostatectomy, transurethral prostate surgery (e.g. TUNA, TUMT, TURP) if performed within 1 year prior to screening, other local prostate cancer therapy (e.g., cryotherapy or brachytherapy) or previous pelvic irradiation at any time prior to screening. * History of prior pelvic surgery requiring low anterior or abdominoperineal resections or rectal surgery. * History of or active inflammatory bowel disease (IBD) such as Crohn's disease or ulcerative colitis. * History of or current perirectal disease that may interfere with interpretation of study outcomes including anal or perianal diseases such as fistula. * Bleeding hemorrhoids requiring medical intervention within the prior three months. * Diagnosed active bleeding disorder or a clinically significant coagulopathy. Note: Patients on anticoagulants may be included if the anticoagulant medication can be discontinued for index procedure. * Active inflammatory or infectious process involving the perineum, gastrointestinal (GI) or urinary tract based on positive diagnosis or suspected diagnosis in the presence of fever \>38⁰ C, WBC \> 12,000/uL. * Compromised immune system or prior diagnoses for human immunodeficiency virus (HIV) (with a detectable viral load within the last 6 months)/acquired immunodeficiency syndrome (AIDS) or autoimmune disease. * If a subject was enrolled in another investigational drug or device trial that had not completed the primary endpoint or that clinically interfered with this study. * Unable to comply with the study requirements or follow-up schedule. * Any condition the Investigator believed would interfere with the intent of the study or would make participation not in the best interest of the patient. * Known iodine sensitivity or allergy * Known polyethylene glycol (PEG) sensitivity or allergy