Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Radiation Oncology cung cấp cho các bạn kiến thức về ngành y đề tài: SemiDecreased 3D observer variation with matched CT-MRI, for target delineation in Nasopharynx cancer. | Rasch et al. Radiation Oncology 2010 5 21 http content 5 1 21 RADIATION ONCOLOGY RESEARCH Open Access Decreased 3D observer variation with matched CT-MRI for target delineation in Nasopharynx cancer Coen RN Rasch1 Roel JHM Steenbakkers2 Isabelle Fitton3 Joop C Duppen1 Peter JCM Nowak4 Pr nlz Ạ D-imoiicC A K3H m PicHn If l 6 l h nnoc WAK i IC riHorc7 D I ilcon8 h l rr-d 2n I lorlz1 Frank A Pameijer Avraham Eisbruch Johannes HAM Kaanders Frank Paulsen Marcel van Herk Abstract Purpose To determine the variation in target delineation of nasopharyngeal carcinoma and the impact of measures to minimize this variation. Materials and methods For ten nasopharyngeal cancer patients ten observers each delineated the Clinical Target Volume CTV and the CTV elective. After 3D analysis of the delineated volumes a second delineation was performed. This implied improved delineation instructions a combined delineation on CT and co-registered MRI forced use of sagittal reconstructions and an on-line anatomical atlas. Results Both for the CTV and the CTV elective delineations the 3D SD decreased from Phase 1 to Phase 2 from to mm for the CTV and from to mm for the elective. There was an increase agreement where the observers intended to delineate the same structure from 36 to 64 surface p for the CTV and from 17 to 59 p for the elective. The largest variations were at the caudal border of the delineations but these were smaller when an observer utilized the sagittal window. Hence the use of sagittal side windows was enforced in the second phase and resulted in a decreased standard deviation for this area from to mm p for the CTV and to mm p for the CTV elective. Discussion Attempts to decrease the variation need to be tailored to the specific causes of the variation. Use of delineation instructions multimodality imaging the use of sagittal windows and an on-line atlas result in a higher agreement on the intended
