A neutron capture therapy system includes a neutron beam irradiation unit that applies neutron beams, a treatment table on which an irradiation object irradiated with the neutron beams is mounted, a storage unit that stores distribution data indicating a distribution of hydrogen atoms or nitrogen atoms of a part to be irradiated of the irradiation object, a gamma ray detection unit that detects gamma rays generated from the irradiation object due to irradiation with the neutron beams, and a neutron flux distribution calculation unit that calculates a distribution of neutron flux in the irradiation object on the basis of the distribution data stored in the storage unit and gamma ray distribution data detected by the gamma ray detection unit.本發明提供一種能夠掌握是否按照治療計劃對照射對象物的內部照射了中子束之中子捕獲治療系統。中子捕獲治療系統(1)中，中子通量分佈計算部(61)能夠依據分佈資料和γ射線分佈資料來計算患者(S)內的中子通量的分佈，前述分佈資料表示記憶於記憶部(64)之患者(S)的患部的氫原子或氮原子的分佈，前述γ射線分佈資料藉由γ射線檢測部(50)檢測。又，由於γ射線檢測部(50)能夠即時檢測γ射線(G)，故中子通量分佈計算部(61)能夠即時計算中子通量的分佈。藉此，藉由將該計算結果與治療計劃的中子通量的分佈進行比較，能夠掌握是否按照治療計劃對患者的內部照射了中子束。
