Jointly using with cancer emission medical therapy, as it can decrease the radiation dose, offer of the radiotherapy reinforcement medicine which can lighten also the side effect. General system (1)[In formula, as for R1 showing halogen atom or cyano basis The complex ring basis of 4 - 8 members R2 the low-grade alkyl group, the imino basis, hydroxyl group, the hydroxy methyl group, may possess the methane sulfonyl oxy basis or the amino group as a substituent, the nitrogen atom 1 - 3 contains The amijinochio basis the hydrogen atom on the nitrogen atom may be substituted with the low-grade alkyl group The guanidinoacetic basis the hydrogen atom on the nitrogen atom may be substituted with the low-grade alkyl group or the cyano basis Low-grade arukiruamijino basis Or 1 pirorijinirumechiru is shown] with the uracil derivative which is displayed or the radiotherapy reinforcement medicine which designates the salt which that pharmacy is allowed as the active ingredient.癌放射療法と併用して放射線量を低減できるとともに、副作用も軽減できる放射線治療増強剤の提供。一般式(1)[式中、R1はハロゲン原子又はシアノ基を示し;R2は置換基として低級アルキル基、イミノ基、水酸基、ヒドロキシメチル基、メタンスルホニルオキシ基若しくはアミノ基を有してもよい、窒素原子を1~3個含有する4~8員の複素環基;窒素原子上の水素原子が低級アルキル基で置換されていてもよいアミジノチオ基;窒素原子上の水素原子が低級アルキル基若しくはシアノ基で置換されていてもよいグアニジノ基;低級アルキルアミジノ基;又は1-ピロリジニルメチル基を示す]で表されるウラシル誘導体又はその薬学的に許容される塩を有効成分とする放射線治療増強剤。
