Prostate cancer is the most common form of cancer in men and the second leading cause of death for men in the United States. The American Cancer Society estimates that approximately 1 in 6 men will be diagnosed with prostate cancer in his lifetime, but only 1 in 35 will die from it. Advances in the detection and treatment of prostate cancer have led to increased rates of survival for patients. Although clinical evidence strongly indicates that treatment practices for prostate cancer are effective, a serious challenge remains in treating patients with radiation therapy—the issue of prostate movement. Studies show that the prostate can move from day-to-day within the patient’s body, depending on how full the bladder is and whether or not there is stool in rectum. Even deep breathing, coughing or laughing can change the location of the prostate.