PROBLEM TO BE SOLVED: To support determination of an appropriate radiation therapy plan policy corresponding to movement of an individual tumor.SOLUTION: A tumor position display device according to an embodiment comprises: an identification unit for identifying a tumor region included in a plurality of three-dimensional medical images with respect to a plurality of time phases； a calculation unit that for each of pixels included in movement paths in the tumor region across the plurality of time phases, calculates a parameter representing a degree of residence of the tumor region in the pixel； and a display unit for displaying a two-dimensional medical image based on at least one three-dimensional medical image of the plurality of three-dimensional medical images using a concentration or color corresponding to a value of the parameter.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2020,JPO&INPIT【課題】個々の腫瘍の動きに対応した適切な放射線治療計画方針の決定を支援すること。【解決手段】実施形態に係る腫瘍位置表示装置は、複数の時相に関する複数の３次元医用画像に含まれる腫瘍領域を特定する特定部と、前記複数の時相に亘る前記腫瘍領域の移動経路に含まれる画素各々について、前記画素各々への前記腫瘍領域の滞留の程度を示すパラメータを算出する算出部と、前記複数の３次元医用画像のうちの少なくとも一の３次元医用画像に基づく２次元医用画像を、前記パラメータの値に応じた濃度又は色で表示する表示部と、を具備する。【選択図】 図１
