PROBLEM TO BE SOLVED: To store a history of effect determination results for multiple courses of therapy.SOLUTION: An effect determination system 1 comprises: display means that display one or multiple series of medical images obtained by executing examination imaging at least once before and after start of a clinical trial (S12) operation means that accepts input of determination results for therapeutic effect determined by a doctor, according to the size of a lesion in the series of medical images before and after start of the clinical trial which are displayed by the display means storage means that stores the determination results of which the input is accepted by the operation means and control means that uses the operation means to accept the input of effect determination results for multiple courses of therapy, with respect to each examination imaging (S13 to S20), and then uses the storage means to store all of accepted determination results for the multiple courses(S21).SELECTED DRAWING: Figure 11COPYRIGHT: (C)2017,JPO&INPIT【課題】複数回の治療の効果の判定結果の履歴を保存する。【解決手段】効果判定システム1は、治験の開始前と開始後に少なくとも1回の検査撮影を行って得られた1又は複数のシリーズの医用画像を表示する(S12)表示手段と、前記表示手段により表示された治験の開始前と開始後の1又は複数のシリーズの医用画像中の病変部の大きさに応じて、医師により判定された治療の効果の判定結果の入力を受け付ける操作手段と、前記操作手段により入力を受け付けた前記判定結果を記憶する記憶手段と、前記操作手段により各検査撮影に対する複数回の治療の効果の判定結果の入力を受け付けさせて(S13~S20)、受け付けた複数回の判定結果のすべてを前記記憶手段に記憶させる(S21)制御手段と、を備える。【選択図】図11