Quality assurance for computed-tomography simulator: In home Z-phantom for mechanical tests of the couch and the gantry  

CT模拟技术的质量保证:使用Z幻影技术测试治疗床和旋转架(英文)

作　　者：Hassan Shafeik Abou-Elenein 

机构地区：[1]Department of Radiotherapy,Children Cancer Hospital

出　　处：《The Chinese-German Journal of Clinical Oncology》2013年第5期237-242,共6页中德临床肿瘤学杂志（英文版）

摘　　要：Objective:The main purpose of this work was to present a Z-phantom manufactured in home (at National Cancer Institute Cairo University) and it's use in a simple way to check the accuracy of the computed-tomography (CT) table movement and CT gantry tilt, also the other general quality control (QC) tests of the CT simulator used at radiotherapy department. Methods:The laser phantom was used to check the external mobile laser position accuracy, for internal image indicator laser beam (light field) the coincidence between light field and radiation exposure at CT simulator was checked using X-Omat ready back film. The Z-phantom was used to check the slice thickness and the table movement and so the gantry tilts. The image quality testes were checked using the CT image quality phantom. TLDs were inserted to the Cicil phantom at the center of each scan volume to estimate the patient dose. Results:The results showed that the difference in the fixed distance between the external mobile laser and the internal image indicator laser beam was less than ± 1 mm; the orientation of the two mobile lateral lasers was coincident. The mechanical movement and the image quality of the CT simulator were within the tolerances and the results were 0.5 mm, 0.2% and 0.6% for the mechanical movement, noise and image uniformity respectively. Conclusion:A CT simulator with a good performance is important for the radiotherapy treatment planning specially with the extremely revolution in radiotherapy techniques, also a rotten quality assurance (QA) program is very important to be shore about the reproducibility of the CT performance. The use of Z-phantom to check the gantry tilt and the table movement is faster than the use of ready back films in these tests.

关 键 词：COMPUTED-TOMOGRAPHY computed-tomography simulator quality control 

分 类 号：R814.4[医药卫生—影像医学与核医学] TP391.41[医药卫生—放射医学]