title: [Application of Imaging-Guided Radiation Therapy in Pelvic Tumor Radiotherapy].
abstract: OBJECTIVE
  To discuss the influence of setup errors on the accuracy of pelvic cancer in IGRT, analysis setup errors and determine the CTV-to-PTV margins.
  
  
  METHODS
  60 pelvic cancer patients treated with Varian 23IX, all of them were performed by CBCT before and after-correction three times in the first week and after that once a week. Then, to measure the setup errors at X(left-right), Y(superior-inferior), Z(anterior-posterior) axis and E(coronal), F(sagittal), G(axial) rotation directions.
  
  
  RESULTS
  530 scans obtained in all, the setup errors in X, Y, Z, E, F, G were (-0.52 ± 4.18) mm, (0.73 ± 4.86) mm, (-0.36 ± 3.62) mm, (0.14 ± 1.20)degrees, (0.13 ± 1.34)degrees, (0.21 ± 1.73)degrees respectively and were much lower after correction at X, Y, Z axis, besides, CTV-to-PTV margins decrease a lot.
  
  
  CONCLUSIONS
  The accuracy of radiotherapy can be highly increased with the use of IGRT in pelvic cancer.
authors.forename: Bing
authors.initials: B
authors.lastname: Wu
authors.forename: Junxiang
authors.initials: J
authors.lastname: He
authors.forename: Jingguo
authors.initials: J
authors.lastname: Fu
authors.forename: Changli
authors.initials: C
authors.lastname: Ruan
mesh_terms: D006801:Humans; D010386:Pelvic Neoplasms / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D061089:Radiotherapy, Image-Guided