CAJ | 학술논문

目的：探讨头肩体垫固定的乳腺癌的放疗摆位误差，并计算合适的临床靶区（ CTV）外扩边界。方法53例乳腺癌患者均接受头肩体垫固定，采用千伏级锥形束CT（ CBCT）扫描并分析左右（ X）、头脚（ Y）、上下（ Z）3个轴方向的线性误差（ X、Y、Z），及绕此3个轴的旋转误差（ Xr、Yr、Zr）。统计误差数据，评价头肩体垫的优劣，并根据公式MPTV＝2?5∑＋0?7δ计算CTV外扩为计划靶区（ PTV）的范围（ MPTV ）。结果53例患者共得到265次摆位误差的数据。265组线性误差绝对值的均值为2?50 mm、2?40 mm、2?20 mm，旋转误差为1?13°、1?11°、0?94°，Z轴方向与X、Y轴方向误差的差异有统计学意义（P＜0?05）。 X、Y、Z 轴3个方向的线性群体系统误差为2?5 mm、2?3 mm、1?9 mm，随机误差为2?5 mm、2?20 mm、2?20 mm；旋转群体系统误差分别为1?03°、1?10°、0?95°，随机误差为0?79°、1?15°、0?72°。建议外扩边界为8?00 mm，7?30 mm、6?30 mm。结论头肩体垫具有较好的摆位精度，利用CBCT测量乳腺癌放疗的摆位误差，为乳腺癌放疗CTV外扩为PTV提供参考依据，提高了乳腺癌放疗的精准性。
목적：탐토두견체점고정적유선암적방료파위오차，병계산합괄적림상파구（ CTV）외확변계。방법53례유선암환자균접수두견체점고정，채용천복급추형속CT（ CBCT）소묘병분석좌우（ X）、두각（ Y）、상하（ Z）3개축방향적선성오차（ X、Y、Z），급요차3개축적선전오차（ Xr、Yr、Zr）。통계오차수거，평개두견체점적우렬，병근거공식MPTV＝2?5∑＋0?7δ계산CTV외확위계화파구（ PTV）적범위（ MPTV ）。결과53례환자공득도265차파위오차적수거。265조선성오차절대치적균치위2?50 mm、2?40 mm、2?20 mm，선전오차위1?13°、1?11°、0?94°，Z축방향여X、Y축방향오차적차이유통계학의의（P＜0?05）。 X、Y、Z 축3개방향적선성군체계통오차위2?5 mm、2?3 mm、1?9 mm，수궤오차위2?5 mm、2?20 mm、2?20 mm；선전군체계통오차분별위1?03°、1?10°、0?95°，수궤오차위0?79°、1?15°、0?72°。건의외확변계위8?00 mm，7?30 mm、6?30 mm。결론두견체점구유교호적파위정도，이용CBCT측량유선암방료적파위오차，위유선암방료CTV외확위PTV제공삼고의거，제고료유선암방료적정준성。
Objective To analyze radiotherapy setup errors of breast cancer sufferers immobilized by head?shoulder?truncus vacuum bags and calculate the clinical target volume ( CTV) enlarging to the planning target volume( PTV) . Methods Fifty?three pa?tients were immobilized by the head?shoulder?truncus vacuum bags. Setup errors were analyzed using kilovoltage cone beam computed tomography ( CBCT) . The data of the linear ( X, Y and Z) and rotational ( Xr,Yr and Zr) setup errors were collected. The statistics were used to estimate the performance of head?shoulder?truncus vacuum bags. According to the formula Mptv=2?5∑+0?7δ, the Mptv was calculated. Results A total of 265 CBCT scans from 53 patients were done. The average absolute value of 265 linear errors were 2?50 mm, 2?40 mm and 2?20 mm at X, Y and Z axes,rotation errors were 1?13°, 1?11°and 0?94°at Xr, Yr and Zr axes, and the er?rors of X and Y axes compared with Z axis had statistical significance ( P<0?05) . For the linear setup errors, the group systematic er?rors were 2?50 mm, 2?30 mm and 1?90 mm, and the group random errors were 2?50 mm, 2?20 mm and 2?20 mm at X, Y and Z ax?es. For the rotational errors, the group systematic errors were 1?03°, 1?10°and 0?95°at Xr, Yr and Zr axes, and the random errors were 0?79°, 1?15° and 0?72° at Xr, Yr and Zr axes. In accordance with formula, the Mptv were recommended as 8?00 mm, 7?30 mm and 6?30 mm at X, Y and Z axes. Conclusion The head?shoulder?truncus vacuum bag has good setup accuracy. The data of setup er?rors which measured by CBCT provide references for CTV enlarging to PTV, and increase the precision in breast cancer radiotherapy.