@article{oai:hirosaki.repo.nii.ac.jp:00005782, author = {寺島, 真悟 and 駒井, 史雄 and 菅原, 大夢 and 高橋, 由佳 and 木村, 直希 and 横山, 昂生 and 岩崎, 晃 and 細川, 洋一郎 and 須崎, 勝正}, issue = {1}, journal = {弘前医学}, month = {Nov}, note = {一般に放射線治療計画装置(RTPS)は,線源回転軸間距離(SAD)を100 cm として製作されており,長い線源回転軸間距離(Long SAD)が設定できないため,全身照射(TBI)ではRTPS は利用できないことが多い.本研究では,自施設のRTPS の限界であるSAD 300 cm で算出されたデータ等を利用し,簡便にSAD 350,400 cm での処方MU 値及び補償物質の厚さを決めることが可能かを検討した.Long SAD での線量特性を取得し,SAD 300 cm でのRTPS の計算結果がLong SAD の条件で測定される値になるように補正を行った.本手法のMU 値と患者に照射されたMU 値との相対誤差は最大で3.6%であった.大腿部及び下腿部で算出された補償物質の厚さは良い結果を示したが,その他の部位では実際よりも誤差が大きかった.一部改善の必要はあるが,RTPS を利用して推定された処方MU 値及び補償物質の厚さはTBI のセットアップに利用可能であることが示唆された. Commercial radiation treatment planning system( RTPS) cannot be used in total body irradiation( TBI)using long source-axis distance (SAD) in many cases, mainly due to the treatment distance outside RTPS specification. We have considered whether it is possible to determine the prescribed MU and the thickness of the compensators at SAD 350 cm, 400 cm, using data calculated at SAD 300 cm which is the limit of RTPS of our own facility. The dose characteristics at long SAD were acquired and corrections were made so that the calculation result of RTPS at SAD 300 cm would be the value measured under the condition of long SAD. The maximum difference between the MU of this method and the MU irradiated to the patient was 3.6%. We got a good result of thickness of the compensators calculated for the femur and lower leg showed, however the differences were greater in other parts. Although some improvement is necessary, it was suggested that the prescribed MU and the thickness of the compensators presumed using RTPS can be used for TBI setup}, pages = {47--55}, title = {RTPS を用いた全身照射におけるMU 値及び補償物質の検討}, volume = {70}, year = {2019} }