Radiation Dose from Computed Tomography Scanning in Songklanagarind Hospital : Diagnostic Reference Levels

Abstract

Title: Radiation dose from computed tomography scanning in Songklanagarind Hospital: Diagnostic Reference Levels Background: Computed tomography (CT), an excellent tool to assist clinicians in medical diagnosis, has seen exponential growth. There has been growing concern about the possibility of CT radiation-induced cancer. Each CT unit has been encouraged to establish their dose reference levels (DRLs) in order to optimize CT radiation dose and imaging quality. Objective: To determine CT radiation dose in terms of median and inter-quartile range of the CTDI and DLP to obtain the institute DRL for CT scans of the head, chest and abdomen for patients at Songklanagarind Hospital, Prince of Songkla University, Hat Yai. Materials and methods: A retrospective analysis of total 464 CT studies from 416 patients who underwent head, chest and abdominal CT scans in Songklanakarind Hospital from July 1st to 31st 2017. The volume CT dose index (CTDIvol), dose length product (DLP) and clinical indications were recorded. The range, mean, and third quartile values were analysed and compared to other standard international DRLs. Kruskal-Wallis rank sum test was used to evaluate significance for the above variables and clinical indications. Results: The DRLs according to our study at the CT unit of Songklanagarind Hospital were: CTDIvol of 57.50 mGy; DLP of 1102.60 mGy.cm for head CT, CTDIvol of 11.63 mGy; DLP of 474.7 mGy.cm for chest CT and CTDIvol of 13.15 mGy; DLP of 624.40 mGy.cm for abdominal CT. The most common clinical indications for CT head, chest and abdomen were stroke (29.1%), malignancy (73.6%) and malignancy (49.6%) respectively. Conclusion: These results show that the DRLs of each CT region have increased when compared to the DRLs of a limited study at Songklanagarind hospital in 2010. However, the values of our study are mostly below standard international DRLs.