Radioprotection No 59-4 | Page 39

Radioprotection 2024 , 59 ( 4 ), 278 – 286 © F . Poursoltani et al ., Published by EDP Sciences , 2024 https :// doi . org / 10.1051 / radiopro / 2024025

Available online at : https :// www . radioprotection . org / ARTICLE Evaluation of barium sulfate-copper breast radiation shield for use in thoracic computed tomography examinations

1 Medical Physics Department , Faculty of Medicine , Semnan University of Medical Sciences , , Semnan , Iran . 2 Cancer Research Center , Semnan University of Medical Sciences , Semnan , Iran . 3 Medical Physics and Radiology Department , Faculty of Medicine , Infectious Diseases Research Center , Gonabad University of Medical

Sciences , Gonabad , Iran . 4 Biomedical Engineering and Medical Physics Department , School of Medicine , Shahid-Beheshti University of Medical Sciences , Tehran , Iran . 5 Social Determinants of Health Research Center , Semnan University of Medical Sciences , Semnan , Iran .

Received : 5 May 2024 / Accepted : 4 July 2024

Abstract – Introduction : In thoracic computed tomography ( CT ) examinations , patients ’ breasts are exposed to high radiation doses , necessitating the reduction of received dose by a radiation shield . The aim of this study is to evaluate the efficiency of a new composition of barium sulfate-copper shield with minimal impact on image quality . Materials and methods : Different breast shields were manufactured using varying weight percentages of copper and BaSO 4 . Thermoluminescent dosimeters ( TLDs ) and thorax phantoms were employed to assess the radiation shielding effectiveness . Image quality , in terms of noise and CT number accuracy , was quantitatively evaluated on a CT dose Index phantom ( CTDI ). Additionally , a controlled trial involving with 30 female participants was conducted to further assess CT image quality and select the best breast radiation shield . Results : The results indicated that the different shield compositions reduced the surface dose by 14.17 – 51.69 %. The shield with a composition of 90 % Cu – 10 % BaSO 4 and 50 % Cu – 50 % BaSO 4 had the lowest noise , while the 100 % bismuth shield had the highest noise . Importantly , the 50 % Cu – 50 % BaSO 4 shield did not cause artifacts in the thoracic CT images . Conclusion : By using the 50 % Cu – 50 % BaSO 4 shield , a significant dose reduction was achieved while maintaining appropriate image quality , making it suitable for clinical applications .

Keywords : Dose reduction / breast radiation shield / thorax CT scanning / image quality / image artifact

1 Introduction

The use of computed tomography ( CT ) as a diagnostic imaging technology has increased in the last two decades ( Abolhadi et al ., 2023 ; Bertho et al ., 2024 ; Lestari et al ., 2023 ). Compared to the other imaging modalities , CT examinations use ionizing radiation with higher doses ( Curtis , 2010 ; Saba et al ., 2019 ; Schöckel et al ., 2020 ), contribute to 70 % of the overall dose of medical patients ( Saba et al ., 2019 ). A report in 2005 indicated that CT scan accounted for only 11 % of all radiological tests ( Curtis , 2010 ). Today , the number of CT examinations around the world increases by 4 % annually ,

* Corresponding authors : behmadim881 . mph @ gmail . com ; keshtkar . dmohammad @ yahoo . com which is a total of about 300 million CT scans per year ( Schöckel et al ., 2020 ).

CT scans are essential examinations for efficiently diagnosing a wide variety of thoracic diseases and are the most accurate technique for lung examinations ( Alonso et al ., 2016 ; Saba et al ., 2019 ). Exposure of radiation-sensitive organs can lead to an increased risk of cancer ( Alonso et al ., 2016 ; Dere , 2022 ; Liao et al ., 2019 ). The cancer risk from chest CT is estimated to be between 25 and 33 cases per 100,000 examinations ( Colletti et al ., 2013 ). In thoracic CT examinations , the breast tissue , as a radiation-sensitive organ , receives a large dose due to its superficiality and its location in the scanning field , even though it is not under clinical examination ( Lestari et al ., 2023 ; Mehnati et al ., 2023 ; Saba et al ., 2019 ). In chest CT , the dose delivered to the breast is usually 0.035 – 0.02 Gy ( Saba et al ., 2019 ; Tappouni et al ., 2013 ). Due to the breast ’ s high radiation sensitivity , with a

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