The present invention provides a radiation therapy simulation device capable of enhancing the simulation precision of therapy dose during the radiation therapy. The radiation therapy simulation device according to this invention (10) comprises: a computation unit (5) for calculating the therapy dose distribution of radiation irradiated on the patient during the radiation therapy and, an information memory unit (3) for storing the medicine dosage information regarding sensitizer or protective agent applied to the patient during the radiation therapy wherein, the computation unit (5) calculates the therapy dose distribution according the medicine dosage information stored in the information memory portion (3).本發明之目的為提供一種提高放射線治療時的治療劑量的模擬精確度之放射線治療模擬裝置。本發明之放射線治療模擬裝置(10)具備:運算部(5),計算在放射線治療中向患者照射之放射線的治療劑量分佈;及資訊記憶部(3),記憶作為在進行放射線治療時向患者供給之敏化劑或防護劑的給藥藥劑的資訊,運算部(5)依據記憶於資訊記憶部(3)之給藥藥劑的資訊來計算治療劑量分佈。1‧‧‧帶電粒子束治療裝置2‧‧‧資訊輸入部3‧‧‧資訊記憶部5‧‧‧運算部5a‧‧‧分佈運算部5b‧‧‧分佈顯示處理部7‧‧‧資訊顯示部
