Analysis of setup errors in helical tomotherapy for bone metastases

VernacularTitle:骨转移螺旋断层调强放疗摆位误差分析
Author: Li'na ZHANG ; Junxia XUE ; Fuhai ZHU ; Weizhang WU ; Yingjie WANG ; Tingyi XIA
Publication Type:Journal Article
Keywords: Bone metastases; Tomotherapy; Setup errors
From: Cancer Research and Clinic 2014;26(1):29-31
CountryChina
Language:Chinese
Abstract: Objective To analyze the setup errors of bone metastases patients by tomotherapy with megavoltage CT (MVCT) and calculate the CTV-PTV margins.Methods 30 patients with bone metastases were enrolled.All patients received tomotherapy,fixed with body net and received MVCT scanning before radiation.The MVCT images were registered with the kilovoltage CT (kVCT) images,the setup errors of X (lateral),Y (vertical),Z (longitudina) and Roll (transverse profile rotation) were obtained according to the formula M =2.5Σ+0.7σ calculated CTV-PTV margin.Results 30 patients were received 494 MVCT images.The errors of systemic±random were (2.85±0.77) mm,(3.11±0.95) mm,(2.21±0.55) mm,and (0,55±0.24)° on X,Y,Z and Roll directions,respectively.The CTV-PTV margins were 3.64 mm,4.17 mm,and 2.86 mm on X,Y,Z directions,respectively.Conclusion The application of image-guided technology for bone metastases can correct positioning in time,which greatly reduces setup errors of the fractionated treatment,further improves the treat accuracy and has a positive value in guiding clinical radiotherapy.