JASTRO研究課題「強度変調放射線治療における線量分布の質的評価基盤の確立」における標準化への取り組み

For standardization of treatment planning and establishment of plan quality assessment in intensity modulated radiotherapy

治療装置，治療計画装置の進歩により，強度変調放射線治療（intensity-modulated radiotherapy：IMRT）が2000年に国内に導入されはや20年以上が経過した。2008年に頭頸部腫瘍，前立腺腫瘍および中枢神経腫瘍の患者に対して，2010年には限局性固形悪性腫瘍の患者に対して保険適用となり，現在では300を超える多くの施設でIMRTが導入されるに至り，様々な部位に対して放射線治療の有力な選択肢の1つとなっている。

The number of institutions introducing IMRT for stage III non-small cell lung cancer is expected to expand in the near future. However, it is well known problem that different treatment planners can generate different dose distributions for the same patient because of its high degree of freedom in the treatment planning phase. Therefore, the authors investigated the degree of variation in dose distribution for the same patient and the same dose constraint. As a result, the variation in dose distribution by treatment planners is very large and is independent of irradiation technique and treatment planning experience. Systematic education in IMRT treatment planning techniques is necessary to reduce this variability.