肿瘤研究与临床
腫瘤研究與臨床
종류연구여림상
CANCER RESEARCH AND CLINIC
2012年
3期
175-178
,共4页
盆腔肿瘤%机载影像系统%放射疗法,调强适形
盆腔腫瘤%機載影像繫統%放射療法,調彊適形
분강종류%궤재영상계통%방사요법,조강괄형
Pelvic neoplasms%On board imager%Radiotherapy,intensity-modulated
目的 应用Varian ix加速器机载影像(OBI)系统研究盆腔肿瘤精确放疗摆位误差,为临床提供参考数据.方法 对适形调强放疗的15例盆腔肿瘤患者进行研究,测量患者左右(X)、头脚(Y)、前后(Z)3个方向的线性误差以及分别以X、Y、Z轴旋转形成的相应U、V、W旋转误差,在线校正摆位误差并记录误差值.统计校正前后的误差,采用二参数法计算临床靶体积(CTV)到计划靶体积(PTV)的外放边界(MPTV).结果 15例患者共行146次首次摆位后和治疗后锥形束CT扫描,在X、Y、Z方向上系统误差(均数)±随机误差(标准差)分别为( 1.23±0.134)、(-2.02±7.96)、(-1.87±3.13)mm,治疗后分别为(0.49±1.14)、(-0.98±2.28)、(-1.87±3.13)mm.X方向的锥形束CT扫描摆位床值在首次摆位后及校正前、后的差异无统计学意义,在Y和Z方向的差异均有统计学意义,校正后的摆位误差在Y和Z方向低于首次摆位后(P＜0.05)；U、V、W3个方向上摆位误差分别为(0.72±1.23)°、( 0.06±1.12)°、(0.12±0.97)°,旋转误差一般不超过3°.由于在线校正只对平移误差进行了校正,U、V、W校正前后无差异.纠正前X、Y、Z方向的MPTV分别为2.55、9.61、5.93 mm,纠正后分别为1.78、3.55、2.74 mm.结论 使用OBI系统在线或离线指导摆位误差的修正可以提高摆位的精度,减少摆位的不确定性,在维持或提高局控率的同时,减少周围正常组织的照射,从而达到提高治疗精度的目的.
目的 應用Varian ix加速器機載影像(OBI)繫統研究盆腔腫瘤精確放療襬位誤差,為臨床提供參攷數據.方法 對適形調彊放療的15例盆腔腫瘤患者進行研究,測量患者左右(X)、頭腳(Y)、前後(Z)3箇方嚮的線性誤差以及分彆以X、Y、Z軸鏇轉形成的相應U、V、W鏇轉誤差,在線校正襬位誤差併記錄誤差值.統計校正前後的誤差,採用二參數法計算臨床靶體積(CTV)到計劃靶體積(PTV)的外放邊界(MPTV).結果 15例患者共行146次首次襬位後和治療後錐形束CT掃描,在X、Y、Z方嚮上繫統誤差(均數)±隨機誤差(標準差)分彆為( 1.23±0.134)、(-2.02±7.96)、(-1.87±3.13)mm,治療後分彆為(0.49±1.14)、(-0.98±2.28)、(-1.87±3.13)mm.X方嚮的錐形束CT掃描襬位床值在首次襬位後及校正前、後的差異無統計學意義,在Y和Z方嚮的差異均有統計學意義,校正後的襬位誤差在Y和Z方嚮低于首次襬位後(P＜0.05)；U、V、W3箇方嚮上襬位誤差分彆為(0.72±1.23)°、( 0.06±1.12)°、(0.12±0.97)°,鏇轉誤差一般不超過3°.由于在線校正隻對平移誤差進行瞭校正,U、V、W校正前後無差異.糾正前X、Y、Z方嚮的MPTV分彆為2.55、9.61、5.93 mm,糾正後分彆為1.78、3.55、2.74 mm.結論 使用OBI繫統在線或離線指導襬位誤差的脩正可以提高襬位的精度,減少襬位的不確定性,在維持或提高跼控率的同時,減少週圍正常組織的照射,從而達到提高治療精度的目的.
목적 응용Varian ix가속기궤재영상(OBI)계통연구분강종류정학방료파위오차,위림상제공삼고수거.방법 대괄형조강방료적15례분강종류환자진행연구,측량환자좌우(X)、두각(Y)、전후(Z)3개방향적선성오차이급분별이X、Y、Z축선전형성적상응U、V、W선전오차,재선교정파위오차병기록오차치.통계교정전후적오차,채용이삼수법계산림상파체적(CTV)도계화파체적(PTV)적외방변계(MPTV).결과 15례환자공행146차수차파위후화치료후추형속CT소묘,재X、Y、Z방향상계통오차(균수)±수궤오차(표준차)분별위( 1.23±0.134)、(-2.02±7.96)、(-1.87±3.13)mm,치료후분별위(0.49±1.14)、(-0.98±2.28)、(-1.87±3.13)mm.X방향적추형속CT소묘파위상치재수차파위후급교정전、후적차이무통계학의의,재Y화Z방향적차이균유통계학의의,교정후적파위오차재Y화Z방향저우수차파위후(P＜0.05)；U、V、W3개방향상파위오차분별위(0.72±1.23)°、( 0.06±1.12)°、(0.12±0.97)°,선전오차일반불초과3°.유우재선교정지대평이오차진행료교정,U、V、W교정전후무차이.규정전X、Y、Z방향적MPTV분별위2.55、9.61、5.93 mm,규정후분별위1.78、3.55、2.74 mm.결론 사용OBI계통재선혹리선지도파위오차적수정가이제고파위적정도,감소파위적불학정성,재유지혹제고국공솔적동시,감소주위정상조직적조사,종이체도제고치료정도적목적.
Objective To study setup errors in precise radiotherapy by Varian ix accelerator OBI system and provide reference data for clinic.Methods 15 patients with pelvic cancer patients were studied in intensity modulated radiation therapy, measurement in patients with left and right (X), head and feet (Y),before and after the (Z) 3 directions respectivelY,the linear error and X,Y,Z axis to form the corresponding U, V, W rotation errors, online error correction anyway, and record the error values. The error data was analyzed before and after corrections using the two-parameter method to calculate the clinical target volume (CTV) to planning target volume (PTV) of putting boundaries (MPTV).Results 15 patients were preformed total 146 times of the first place after a and after treatment of conical CT scan,in the X,Y,Z direction system error ((x)) ± random error (s) were (1.23±0.134) mm,(2.02±7.96) mm and (1.87±3.13) mm,after treatment for respectively (0.49±1.14) mm,(0.98±2.28) mm and (1.87±3.13) mm.There was no significant difference on X direction of the tapered bed CT scan in the first place,before and after calibration,in Y and Z direction there were significant differences, corrected position error in Y and Z direction is lower compared with that of primary (P ＜ 0.05); the setup error were (0.72±1.23)°,(0.06±1.12)°,(0.12±0.97)° on U,V and W direction respectively. rotate error in general was not more than 3°. Since online correction only worked to the translation error correction, There was no difference in U,V and W before and after correction.The MPTV was 2.55,9.61 and 5.93 mm on X,Y,Z direction before correcting. Conclusions Online or offline using the OBI system to guide positioning error correction can improve the positioning accuracy and reduce the positioning uncertainty,while maintaining or increasing local control rate at the same time,reducing exposure to surrounding normal tissue,so as to improve treatment accuracy purposes.
