Assessment of bladder filling during prostate cancer radiation therapy with ultrasound and cone-beam CT oleh Kiran Chauhan, Daniel K. Ebner, Katherine Tzou, Karen Ryan, Jackson May, Tasmeem Kaleem, Daniel Miller, William Stross, Timothy Dean Malouff, Robin Landy, Gerald Strong, Steve Herchko, Chris Serago, Daniel Michael Trifiletti, Robert Clell Miller, Steven Buskirk, Mark R. Waddle