This invention, with cancer radiotherapy it jointly uses be able to decrease the radiation dose, the radiotherapy reinforcement medicine which can lighten also the side effect it regards. General system (1)(In formula, R1, R2 and R4, equality or differing, the hydrogen atom, hydroxyl group or shows the hydroxyl group which is protected and (however, R1, R excludes the case where everything of2 and R4 is the hydrogen atom), R3, the halogen atom, the amino group, the carboxyl group, the karubamoiru basis, the cyano basis and the nitro group, carbon count the alkyl group of 1 - 6, carbon count the arukeniru basis or carbon count of 2 - 6 - 6 alkoxy group shows the carbonyl group where has 1.)So the radiotherapy reinforcement medicine which designates the pyridine derivative which is displayed as the active ingredient.本発明は、癌放射線療法と併用して放射線量を低減でき、副作用も軽減できる放射線治療増強剤に関する。一般式(1)(式中、R1、R2及びR4は、同一又は異なって、水素原子、水酸基又は保護された水酸基を示し(但し、R1、R2及びR4の全てが水素原子である場合を除く)、R3は、ハロゲン原子、アミノ基、カルボキシル基、カルバモイル基、シアノ基、ニトロ基、炭素数1~6のアルキル基、炭素数2~6のアルケニル基又は炭素数1~6のアルコキシ基を有するカルボニル基を示す。)で表されるピリジン誘導体を有効成分とする放射線治療増強剤。
