Sains Malaysiana 45(4)(2016): 567–573

Evaluating Organ Dose and Radiation Risk of Routine CT Examinations in Johor, Malaysia

(Penilaian Dos Organ dan Risiko Radiasi Pemeriksaan CT Rutin di Johor, Malaysia)

M.K.A. KARIM^1,2*, S. HASHIM¹, A. SABARUDIN³, D.A. BRADLEY⁴ & N.A. BAHRUDDIN¹

¹Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor Darul Takzim, Malaysia

²Division of Public Health, Johor State Health Department, 80100 Johor Bahru, Johor Darul Takzim, Malaysia

³Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia

⁴Centre for Nuclear & Radiation Physics, Department of Physic, University of Surrey, Guildford, GU2 7XH, United Kingdom

Diserahkan: 14 Ogos 2015/Diterima: 1 Oktober 2015

ABSTRACT

In this study, radiation doses from CT scan procedures and its related risks to the patients from five hospitals in Johor State, Malaysia were analyzed. The survey was conducted in a two-month period encompassing data for 460 patients with the number for each hospital being set at 32, 30 and 30 samples for CT brain, CT thorax and CT abdomen, respectively. The results indicated that the CTDIw, DLP and effective dose values ranged from 7.0±1.3 to 67.7±3.4 mGy, 300.2±135.4 to 1174.2±79.9 mGy.cm and 1.5±0.2 to 11.7±6.65 mSv, respectively. The organ doses were calculated using CT EXPO software (Ver. 2.3.1, Germany) and were found to vary within the hospitals and the type of the CT examinations. Effective cancer risks per procedure were calculated by multiplying organ dose with the nominal cancer risk that was adapted from International Commission on Radiological Protection (ICRP) Publication 103. The values ranged from 0 to 1449 cancer cases per one million procedures for these three routine examinations. This present work showed that the CT systems can impart high radiation doses and increase of radiation risk to patients if optimization protocols are ignored.

Keywords: CT scan; effective dose; organ equivalent dose; risk assessment

ABSTRAK

Dalam kajian ini, dos sinaran daripada prosedur imbasan CT dan risiko yang berkaitan dengan pesakit daripada lima hospital di Johor, Malaysia telah dianalisis. Kajian ini dijalankan dalam tempoh dua bulan meliputi data untuk 460 pesakit dengan bilangan untuk setiap hospital ditetapkan masing-masing dengan 32, 30 dan 30 sampel untuk CT otak, CT toraks dan CT abdomen. Keputusan menunjukkan bahawa CTDIw, DLP dan dos berkesan, masing-masing berjulat 7.0±1.3 hingga 67.7±3,4 mGy, 300.2±135.4 hingga 1174.2±79.9 mGy.cm dan 1.5±2 hingga 11.7±6.65 mSv. Dos pada organ telah diukur menggunakan perisian CT-EXPO (Versi 2.3.1, Jerman) dan didapati berbeza-beza antara hospital. Risiko kanser efektif bagi setiap prosedur dikira dengan mendarabkan dos organ dengan risiko kanser nominal yang telah disesuaikan daripada laporan Suruhanjaya Antarabangsa bagi Perlindungan Radiologi (ICRP) Terbitan 103. Nilainya adalah berjulat antara 0-1449 kes kanser bagi setiap satu juta prosedur bagi tiga pemeriksaan rutin ini. Kajian ini mendedahkan sistem CT boleh menyebabkan dos radiasi yang tinggi dan peningkatan risiko radiasi kepada pesakit jika protokol pengoptimuman diabaikan.

Kata kunci: Dos berkesan; dos setara organ; imbasan CT; penilaian risiko

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*Pengarang untuk surat-menyurat; email: khalis.karim@gmail.com