Comparison of orthogonal kilovolt X-ray images and cone-beam CT matching results in setup error assessment and correction for EB-PBI during free breathing
Wang Wei*, Li Jianbin, Hu Hongguang, Ma Zhifang, Xu Min, Fan Tingyong, Shao Qian, Ding Yun
*Departmentof Radiation Oncology, Shandong Cancer Hospital& Institute, Ji′nan 250117, China
Abstract:Objective To compare the differences in setup error (SE) assessment and correction between the orthogonal kilovolt X-ray images and CBCT in EB-PBI patients during free breathing. Methods Nineteen patients after breast conserving surgery EB-PBI were recruited. Interfraction SE was acquired using orthogonal kilovolt X-ray setup images and CBCT, after on-line setup correction, calculate the residual error and compare the SE, residual error and setup margin (SM) quantified for orthogonal kilovolt X-ray images and CBCT. Wilcoxon sign-rank test was used to evaluate the differences. Results The CBCT based SE (systematic error, Σ) was smaller than the orthogonal kilovolt X-ray images based Σ in AP direction (-1.2 mm vs 2.00 mm;P=0.005), and there was no statistically significant differences for three dimensional directions in random error (σ)(P=0.948,0.376,0.314). After on-line setup correction, CBCT decreases setup residual error than the orthogonal kilovolt X-ray imagesin AP direction (Σ:-0.20 mm vs 0.50 mm,P=0.008;σ:0.45 mm vs 1.34 mm,P=0.002). And also the CBCT based SM was smaller than orthogonal kilovolt X-ray images based SM in AP direction (Σ:-1.39 mm vs 5.57 mm,P=0.003;σ:0.00 mm vs 3.2 mm,P=0.003). Conclusions Compared with kilovolt X-ray images, CBCT underestimate the setup error in the AP direction, but decreases setup residual error significantly. An image-guided radiotherapy and setup error assessment using kilovolt X-ray images for EB-PBI plans was feasible.
Wang Wei,Li Jianbin,Hu Hongguang et al. Comparison of orthogonal kilovolt X-ray images and cone-beam CT matching results in setup error assessment and correction for EB-PBI during free breathing[J]. Chinese Journal of Radiation Oncology, 2014, 23(2): 147-149.
[1] 李建彬,于金明,范廷勇,等.部分乳腺照射在乳腺癌保乳术后放疗中的应用[J].中华肿瘤杂志,2008,30:81-84. [2] 李建彬,于金明,徐敏.乳腺癌保乳术后放疗进展[J].中华放射肿瘤学杂志,2010,19:170-175. [3] Topolnjak R, Sonke JJ, Nijkamp J, et al. Breast patient setup error assessment:comparison of electronic portal image devices and cone-beam computed tomography matching results[J]. Int J Radiat Oncol Biol Phys,2010,78:1235-1243. [4] 王玮,李建彬.保乳术后外照射靶区位移的确定与校正[J].中华放射肿瘤学杂志,2011,20:259-262. [5] van Herk M, Remeijer P, Rasch C, et al. The probability of correct target dosage:dose-population histograms for deriving treatment margins in radiotherapy[J]. Int J Radiat Oncol Biol Phys,2000,47:1121-1135. [6] van Herk M. Errors and margins in radiotherapy[J]. Semin Radiat Oncol,2004,14:52-64. [7] Hector C, Webb S, Evans PM.A simulation of the effects of set-up error and changes in breast volume on conventional and intensity-modulated treatments in breast radiotherapy[J]. Phys Med Bio1,2001,46:1461-1471. [8] Chopra S, Dinshaw KA, Kamble R, et al.Breast movement during normal and deep breathing, respiratory training and set up errors:implications for external beam partial breast irradiation[J].Br J Radial,2006,79:766-773. [9] Gierga DP, Riboldi M, Turcotte JC, et al. Comparison of target registration errors for multiple image-guided techniques in accelerated partial breast irradiation[J]. Int J Radiat Oncol Biol Phys,2008,70:1239-1246. [10] 王冬青,李洪升,周涛,等.乳腺癌保乳术后锥形束CT引导全乳精确放疗的最佳配准模板选择[J].中华放射医学与防护杂志,2010,30:299-302. [11] 李建彬,刘翠翠,孙涛,等.千伏特平片引导ABC辅助部分乳腺外照射术腔中银夹位移研究[J].中华放射肿瘤学杂志,2009,18:134-137. [12] 韩磊,李建彬,于金明,等.影像引导kV级X线成像测定自由呼吸状态下保乳术后部分乳腺外照射术腔中银夹位移[J].中华肿瘤杂志,2009,31:237-238. [13] 李建彬,韩磊,张英杰,等.千伏X线平片测定自主呼吸控制和自由呼吸状态下保乳术后术腔中银夹位移的比较研究[J].中华放射肿瘤学杂志,2010,19:236-240. [14] White EA, Cho J, Vallis KA, et al.Cone beam computed tomography guidance for setup of patients receiving accelerated partial breast irradiation[J]. Int J Radiat Oncol Biol Phys,2007,68:547-554. [15] Fatunase T, Wang Z, Yoo S, et al. Assessment of the residual error in soft tissue setup in patients undergoing partial breast irradiation:results of a prospective study using cone-beam computed tomography[J]. Int J Radiat Oncol Biol Phys,2008,70:1025-1034. [16] Cox BW, Horst KC, Thornton S,et al. Impact of increasing margin around the lumpectomy cavity to define the planning target volume for 3D conformal external beam accelerated partial breast irradiation[J]. Med Dosim,2007,32:254-262. [17] Cao J, Roeske JC, Chmura SJ, et al.Calculation and prediction of the effect of respiratory motion on whole breast radiation therapy dose distributions[J]. Int J Radiat Oncol Biol Phys,2009,34:126-132. [18] Bissonnette JP, Balter PA, Dong L, et al. Quality assurance for image-guided radiation therapy utilizing CT-based technologies:a report of the AAPM TG-179[J]. Med Phys,2012,39:1946-1963. [19] Langen KM, Willoughby TR, Meeks SL, et al. Observations on real-time prostate gland motion using electromagnetic tracking[J]. Int J Radiat Oncol Biol Phys,2008,71:1084-1090.