A triple endorectal ballooning (TERB) system for prostate cancer radiotherapy may include a first balloon unit, a second balloon unit, a third balloon unit, a central passageway and a cover. The first balloon unit may include a first balloon and a first passageway connected to the first balloon. The second balloon unit may include a second balloon and a second passageway connected to the second balloon. The third balloon unit may include a third balloon and a third passageway connected to the third balloon. The central passageway may be arranged between the first to third balloon units to excrete a bowel gas. The cover may be configured to cover the first to third passageways and the central passageway and to support the first to third balloon units.