Evaluation of radiation dose in computed tomography simulator

Authors

  • Sarayut Kornsopa Radiation Therapy Unit, Radiological Department, Sakon Nakhon Hospital
  • Adilan Sahoh Department of Radiological Technology, Faculty of Allied Health Sciences, Thammasat University
  • Siriyakorn Kiawbanhan Department of Radiological Technology, Faculty of Allied Health Sciences, Thammasat University
  • Sowitchaya Huakham Department of Radiological Technology, Faculty of Allied Health Sciences, Thammasat University

Keywords:

computed tomography simulation, radiation dose, dose reference levels

Abstract

Background: Computed tomography (CT) simulator is the gold standard tool for radiotherapy treatment planning. In CT imaging the radiation dose must be as low as possible to minimize the patient’s risk but still sufficiently high to obtain a satisfying image quality for diagnostic and treatment.

Objectives: To evaluate the radiation dose of patients who underwent a CT simulation for radiotherapy treatment planning at Sakon Nakhon Hospital and to compare the radiation dose with diagnostic reference levels (DRLs) and dose reference levels for radiotherapy CT simulation (DRLs of RT CT).

Materials and methods: Computed tomography dose index in air (CTDIair) and volume computed tomography dose index (CTDIvol) were measured. The measured CTDIvol was then compared with the displayed CT scanner CTDIvol. After that, 1-year CTDIvol and dose length product (DLP) were retrospectively collected from patient records between October 1st, 2020 and September 30th, 2021. The data included patients of the head and neck (H&N), thorax, and pelvis simulation protocols. The CTDIvol and DLP values obtained with parameters were compared with the DRLs and DRLs of RT CT.

Results: The CT scanner output was 0.20 mGy/mAs. The displayed CT scanner CTDIvol was higher than the measured CTDIvol. The deviations between measured and reported CTDIvol of H&N, thorax, and pelvis protocols were 7.20%, 2.14% and 1.36%, respectively. The median values of CTDIvol and DLP were 15.97 mGy and 638.11 mGy.cm for the H&N protocol, 11.54 mGy and 487.64 mGy.cm for the thorax protocol, and 12.01 mGy and 541.25 mGy.cm for the pelvis protocol, respectively.

Conclusion: There were no CT simulation protocols in which the radiation doses exceeded the DRLs and dose reference levels for CT in radiation oncology. The radiation doses in computed tomography for radiotherapy treatment planning were properly optimized following the imaging guidelines.

References

Martin CJ, Kron T, Vassileva J, Wood TJ, Joyce C, Ung NM, et al. An international survey of imaging practices in radiotherapy. Phys Med. 2021;90:53-65.

Aird EG, Conway J. CT simulation for radiotherapy treatment planning. Br J Radiol. 2002;75:937-49.

Raman SP, Mahesh M, Blasko RV, Fishman EK. CT scan parameters and radiation dose: practical advice for radiologists. J Am Coll Radiol. 2013;10:840-6.

Leitão CA, Salvador GLO, Tazoniero P, Warszawiak D, Saievicz C, Jakubiak RR, et al. Dosimetry and comparison between different CT protocols (low Dose, ultralow dose, and conventional CT) for lung nodules' detection in a phantom. Radiol Res Pract. 2021;2021:6667779.

Huang K, Rhee DJ, Ger R, Layman R, Yang J, Cardenas CE, et al. Impact of slice thickness, pixel size, and CT dose on the performance of automatic contouring algorithms. J Appl Clin Med Phys. 2021;22:168-74.

Mosher EG, Butman JA, Folio LR, Biassou NM, Lee C. Lens dose reduction by patient posture modification during neck CT. AJR Am J Roentgenol. 2018;210:1111-7.

Agency IAE. Radiation protection and safety of radiation sources: international basic safety standards. Vienna: International Atomic Energy Agency; 2011.

McCollough C, Branham T, Herlihy V, Bhargavan M, Robbins L, Bush K, et al. Diagnostic reference levels from the ACR CT accreditation program. J Am Coll Radiol. 2011;8:795-803.

Vañó E, Miller DL, Martin CJ, Rehani MM, Kang K, Rosenstein M, et al. ICRP publication 135: diagnostic reference levels in medical Imaging. Ann ICRP. 2017;46:1-144.

(Thailand) MoPH. National diagnostic reference levels in Thailand 2021. 2021 [cited 2023 3 Jul]. Available from: https://webapp1.dmsc.moph.go.th/petitionxray/course2/assets/download/DRLsTotal.pdf.

Donmoon T, Chusin T. Establishment of local diagnostic reference levels for commonly performed computed tomography examinations in Thai cancer hospitals. Thai J Rad Tech. 2021;46:35-42.

Kanda R, Akahane M, Koba Y, Chang W, Akahane K, Okuda Y, et al. Developing diagnostic reference levels in Japan. Jpn J Radiol. 2021;39:307-14.

Wakeford R. Does low-level exposure to Ionizing radiation increase the risk of cardiovascular disease? Hypertension. 2019;73:1170-1.

Mathews JD, Forsythe AV, Brady Z, Butler MW, Goergen SK, Byrnes GB, et al. Cancer risk in 680,000 people exposed to computed tomography scans in childhood or adolescence: data linkage study of 11 million Australians. Bmj. 2013;346:f2360.

Virag P, Hedesiu M, Soritau O, Perde-Schrepler M, Brie I, Pall E, et al. Low-dose radiations derived from cone-beam CT induce transient DNA damage and persistent inflammatory reactions in stem cells from deciduous teeth. Dentomaxillofac Radiol. 2019;48:20170462.

Wongsanon W, Phaorod J, Hanpanich P, Awikunprasert P. Study survey of dose-length product from computed tomography examination in Srinagarind hospital, Khon Kaen university. Srinagarin Med J. 2020;35:433-7.

Ngaodingam W. Radiation dose in patient underwent computed tomography scan at Sichon Hospital. J Nakornping Hosp. 2021;12:97-107.

Wood TJ, Davis AT, Earley J, Edyvean S, Findlay U, Lindsay R, et al. IPEM topical report: the first UK survey of dose indices from radiotherapy treatment planning computed tomography scans for adult patients. Phys Med Biol. 2018;63:185008.

Sanderud A, England A, Hogg P, Fosså K, Svensson SF, Johansen S. Radiation dose differences between thoracic radiotherapy planning CT and thoracic diagnostic CT scans. Radiography. 2016;22:107-11.

Radiology TACo. ACR–AAPM–SPR practice parameter for diagnostic reference levels and achievable doses in medical X-ray Imaging. practice guideline. revised 2018 (resolution 40).2018 [cited 2023 3 Jul]. Available from: https://www.acr.org/-/media/ACR/Files/Practice-Parameters/diag-ref-levels.pdf.

UK G. National diagnostic reference levels (NDRLs) for the UK [updated November, 2022; cited 2023 3 Jul]. Available from: https://www.gov.uk/government/publications/diagnostic-radiology-national-diagnostic-reference-levels-ndrls/ndrl.

Rao M, Kadavigere D, Sharan D, Sukumar D, GC M, Dsouza M, et al. Establishment of diagnostic reference level and radiation dose variation in head & neck and pelvis treatment planning in radiation therapy computed tomography. F1000Research. 2022;11:489.

Božanić A, Šegota D, Debeljuh DD, Kolacio M, Radojčić Đ S, Ružić K, et al. National reference levels of CT procedures dedicated for treatment planning in radiation oncology. Phys Med. 2022;96:123-9.

Zalokar N, Žager Marciuš V, Mekiš N. Establishment of national diagnostic reference levels for radiotherapy computed tomography simulation procedures in Slovenia. Eur J Radiol. 2020;127:108979.

Clerkin C, Brennan S, Mullaney LM. Establishment of national diagnostic reference levels (DRLs) for radiotherapy localisation computer tomography of the head and neck. Rep Pract Oncol Radiother. 2018;23:407-12.

Forss V, Yli-Ollila H, Vatanen J, Kölhi P, Poutanen VP, Palomäki A. The reliability of radiation dose display of a computed tomography scanner. Eur J Radiol. 2021;8:100345.

Sodkokkruad P, Asavaphatiboon S, Thanabodeebonsiri J, Tangboonduangjit P. Comparison of computed tomography dose index measuring by two detector types of computed tomography simulator. Thai J Rad Tech. 2018;43:64-8.

Tomic N, Papaconstadopoulos P, Aldelaijan S, Rajala J, Seuntjens J, Devic S. Image quality for radiotherapy CT simulators with different scanner bore size. Physica Medica. 2018;45:65-71.

Downloads

Published

2023-10-27 — Updated on 2023-10-27

Versions

How to Cite

1.
Kornsopa S, Sahoh A, Kiawbanhan S, Huakham S. Evaluation of radiation dose in computed tomography simulator. J Thai Assn of Radiat Oncol [Internet]. 2023 Oct. 27 [cited 2024 Dec. 21];29(2):R32-R45. Available from: https://he01.tci-thaijo.org/index.php/jtaro/article/view/263594

Issue

Vol. 29 No. 2 (2023): July - December

Section

Original articles

License

Copyright (c) 2023 Thai Association of Radiation Oncology

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

บทความที่ได้รับการตีพิมพ์เป็นลิขสิทธิ์ของวารสารมะเร็งวิวัฒน์ สมาคมรังสีรักษาและมะเร็งวิทยาแห่งประเทศไทย

ข้อความที่ปรากฏในบทความแต่ละเรื่องในวารสารวิชาการเล่มนี้เป็นความคิดเห็นส่วนตัวของผู้เขียนแต่ละท่านไม่เกี่ยวข้องกับสมาคมรังสีรักษาและมะเร็งวิทยาแห่งประเทศไทย และบุคคลากรท่านอื่น ๆ ใน สมาคมฯ แต่อย่างใด ความรับผิดชอบองค์ประกอบทั้งหมดของบทความแต่ละเรื่องเป็นของผู้เขียนแต่ละท่าน หากมีความผิดพลาดใดๆ ผู้เขียนแต่ละท่านจะรับผิดชอบบทความของตนเองแต่ผู้เดียว