Sebelego Ida-Keshia, Acho Sussan, Rae William I D
Department of Clinical Sciences, Faculty of Health and Environmental Sciences, Central University of Technology, Bloemfontein, South Africa.
Department of Medical Physics, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa.
SA J Radiol. 2024 Oct 31;28(1):2960. doi: 10.4102/sajr.v28i1.2960. eCollection 2024.
In CT, the volumetric CT dose index (CTDI), dose-length product (DLP) and patient's size-specific dose estimates (SSDE) are used as diagnostic reference level (DRL) metrics.
To develop clinical local DRL values for CT chest-abdomen-pelvis (CAP) examinations using the CTDI, DLP and SSDE, and to determine the image quality achieved.
In total, 201 cancer patients were included in the study. The scanning parameters, dose metrics from the CT unit and participants' body mass index (BMI) were documented. The local CT DRL values for CAP examinations were defined as the median and 75th percentiles of the dose distribution.
The local DRL values given in terms of median CTDI ranged between 8.4 mGy and 12.7 mGy for the different types of cancers. The median DLPs ranged from 848 to 1173.4 mGy.cm for the various cancers. Generally, the radiation dose was directly proportional to the BMI and number of scan phases. Significant differences were observed between the DRLs for the various size-related parameters, number of scan phases and BMI classifications. The image quality was clinically satisfactory.
No baseline data for clinical DRL values were available for this medical oncology department. The achieved DRLs were similar to published size-specific DRLs. The image quality was maintained during CT imaging. Dose optimisation and image quality assessment should be implemented to ensure optimal scanning parameters for different cancers in CT CAP examinations.
The first size-specific local DRL values for CT CAP investigations carried out on oncology patients in South Africa have been established.
在CT检查中，容积CT剂量指数（CTDI）、剂量长度乘积（DLP）和患者体型特异性剂量估计值（SSDE）被用作诊断参考水平（DRL）指标。
利用CTDI、DLP和SSDE制定胸部-腹部-盆腔（CAP）CT检查的临床局部DRL值，并确定所达到的图像质量。
本研究共纳入201例癌症患者。记录扫描参数、CT设备的剂量指标以及参与者的体重指数（BMI）。CAP检查的局部CT DRL值定义为剂量分布的中位数和第75百分位数。
不同类型癌症的中位数CTDI给出的局部DRL值在8.4 mGy至12.7 mGy之间。各种癌症的中位数DLP范围为848至1173.4 mGy·cm。一般来说，辐射剂量与BMI和扫描期数成正比。在不同尺寸相关参数、扫描期数和BMI分类的DRL之间观察到显著差异。图像质量在临床上令人满意。
该肿瘤内科尚无临床DRL值的基线数据。所获得的DRL与已发表的体型特异性DRL相似。CT成像过程中图像质量得以维持。应实施剂量优化和图像质量评估，以确保CT CAP检查中针对不同癌症的最佳扫描参数。
已建立了南非肿瘤患者进行CT CAP检查的首个体型特异性局部DRL值。
