الفهرس 
Verification of setup errors in Head and Neck cancer patients treated by 3D conformal radiotherapy (3D- CRT) and Intensity modulated Radiotherapy (IMRT) using electronic portal image device (EPID)
التحقق من أخطاء الإعداد في مرضي سرطان الرأس والرقبة الذين تم معالجتهم بعلاج إشعاعي ثلاثي الأبعاد بواسطة وحدة التصوير الإلكتروني الملحقة بالحهازOnly 14 pages are availabe for public view
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Abstract
Purpose: To study the geometric uncertainties in the treatment of head and neck and evaluate the adequacy of the margins employed for the planning target volume (PTV) generation in the treatment of patient undergoing intensity-modulated radiation therapy (IMRT) and 3 D- conformal radiotherapy (3DCRT) of head and neck cancer. Materials and methods: Fifty head and neck cancer patients were treated between 2014&2015 with dynamic IMRT 45(pt)& 3CDRT (5)using 6 MV X- ray beam UNIQUE LINAC. Weekly portal images of setup fields which were anterior-posterior and lateral portal images were acquired for each patient with an amorphous silicon EPID Varian aS500. These images were matched with the reference image from Varian Acuity simulator using the Varis vision software (Version 7.3.10). Six anatomical landmarks were selected for comparison. The displacement of portal image from the reference image was recorded in X (Left-Right, L-R ) and Z (Anterior-Posterior, A-P) direction for anterior field and Z(Anterior-Posterior, A-P), ) &(Superior-Inferior, S-I) Y direction for lateral field. The systematic and random error for individual and population were calculated. Then the population-based margins were obtained