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040 _aEG-GiCUC
_beng
_cEG-GiCUC
041 0 _aeng
049 _aDeposite
097 _aM.Sc
099 _aCai01.12.04.M.Sc.2017.Mo.D
100 0 _aMohamed Abdelmajeed Ibrahim Khalil
245 1 0 _aDosimetric evaluation of patient setup errors via IG-IMRT /
_cMohamed Abdelmajeed Ibrahim Khalil ; Supervised Wael M. Elshemey , Ehab M. Attalla , Nashaat Ahmed Deiab
246 1 5 _aتقييم قياس الجرعة لأخطاء ضبط المريض عن طريق العلاج الإشعاعي متغيير الشدة الموجة بالتصوير
260 _aCairo :
_bMohamed Abdelmajeed Ibrahim Khalil ,
_c2017
300 _a94 P. :
_bcharts , facsimiles ;
_c25cm
502 _aThesis (M.Sc.) - Cairo University - Faculty of Science - Department of Biophysics
520 _aThe goal of radiotherapy treatment is to deliver maximum dose to tumor and minimum dose elsewhere. During fractionated radiation therapy, setup errors are an inherent part of the radiation treatment process. Image Guided Radiation Therapy (IGRT) can used to increase the agreement between planned treatment and actual delivered dose to patient. In this work setup errors are detected using Kilo-voltage Cone Beam Computed Tomography (kV-CBCT). The specific patient (personalised/individual) setup errors are applied on Head and Neck (H&N) and prostate Intensity Modulated Radiation Therapy (IMRT) treatment plans using Simultaneous Integrated Boost (SIB) technique by varying the plan isocenter in order to evaluate the extent of the effect of setup errors and to investigate their impact on target volumes with the help of Dose-Volume Histogram (DVH) parameters and dosimetric indices. Results show that prostate systematic errors are 0.44, 0.54 and 0.73 mm while random errors are 3.16, 2.46 and 3.87 mm in LR, SI and AP directions, respectively. H&N systematic errors are 0.32, 0.28 and 0.23 mm while random errors are 2.22, 2.26 and 1.83 mm in LR, SI and AP directions, respectively. For 23 H&N patients, significant differences (p-value < 0.05) are reported between original and shifted Planning Target Volumes (PTVs) due to setup errors. After consideration of setup errors for the three investigated target volumes (target-70, target-60 and target-54), the mean dose delivered to 95% of target volume (D95%) is significantly reduced from 58.6 to 57.2 Gy for target-60, significant deteriorations in target dose homogeneity for target-70 and target-60 are measured using the Homogeneity Index (HI) while no significant change in dose conformity is detected using Conformity Index (CI). For 12 prostate patients, at individual level, the D95% is always higher for original isocenter compared to shifted isocenter for target-81 and target-56. The mean D95% value is significantly (p < 0.05) reduced from 78.6 to 73.9 Gy and from 54.4 to 52.8 Gy for target-81 and target-56, respectively. Significant reduction in the dose conformity is observed for target-81 as measured using CI parameter. Significant reduction in the homogeneity of target dose distribution (higher HI values) for shifted targets (50% and 69% for target-81 and target-56, respectively) is also reported compared to original plans
530 _aIssued also as CD
653 4 _aIMRT
653 4 _aIntegral dose
653 4 _aSecondary Malignancies
700 0 _aEhab M. Attalla ,
_eSupervisor
700 0 _aNashaat Ahmed Deiab ,
_eSupervisor
700 0 _aWael M. Elshemey ,
_eSupervisor
856 _uhttp://172.23.153.220/th.pdf
905 _aNazla
_eRevisor
905 _aShimaa
_eCataloger
942 _2ddc
_cTH
999 _c65408
_d65408