Sains Malaysiana 49(8)(2020): 1981-1985

http://dx.doi.org/10.17576/jsm-2020-4908-20

Thermoluminescence Dosimetric Characteristics of Fabricated Germanium (Ge) Doped Optical Fibres for Electron Beams Dosimetry: A Preliminary Study

 (Pencirian Dosimeter Pendar Gerlap Terma terhadap Gentian Optik Dop Germanium yang Difabrikasi bagi Pengukuran Dos dalam Pancaran Elektron: Sebuah Kajian Awal)

ZABARIAH ZAKARIA^1,3, MOHD ZAHRI ABDUL AZIZ² & NORAMALIZA MOHD NOOR^*1,4

¹Department of Imaging, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia

²Oncological and Radiological Sciences Cluster, Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia (USM), 13200 Bertam, Pulau Pinang, Malaysia

³Universiti Kuala Lumpur British Malaysian Institute (UniKL BMI), Bt 8 Jalan Sg Pusu, 53100 Gombak, Selangor Darul Ehsan, Malaysia

⁴Department of Radiology, Hospital Pengajar Universiti Putra Malaysia (HPUPM), Persiaran Mardi-UPM,
43400 Serdang, Selangor Darul Ehsan, Malaysia

Diserahkan: 2 Oktober 2019/Diterima: 26 Mac 2020

ABSTRACT

The basic dosimetric favourable responses of tailored fabricated germanium (Ge) doped cylindrical optical fibres, make use of 2.3% mol have been extensively studied with clinical electron beams irradiation in terms of dose linearity, reproducibility, fading signals, minimum detectable dose (MDD), energy- and field size dependence. The irradiation was performed at the Radiotherapy Unit, Advanced Medical and Dental Institute (AMDI), which utilizes Elekta Synergy^® linear accelerator (LINAC) at 6-, 9-, 12- and 15 MeV electron beam energies at specific doses ranging from 1 to 5 Gy. Thermoluminescence (TL) signals exhibited a linear dose-response overdose ranges, mean reproducibility with a coefficient of variation (CV) of better than 10% and no dependency with different field sizes at p > 0.05. The MDD values were typically 3.51 to 4.13 mGy. The minimum TL fading of the fabricated Ge-doped cylindrical optical fibres was reported favourably for 9 MeV electron beam at day of 74.

Keywords: Dose linearity; optical fibres; thermoluminescence (TL)

ABSTRAK

Pencirian asas yang sesuai terhadap tindak balas germanium (Ge) dop gentian optik yang berbentuk silinder dengan kepekatan 2.3% mol telah dikaji secara meluas dengan penyinaran pancaran elektron klinikal dari segi kelinearan terhadap dos, kebolehulangan semula, kemerosotan isyarat, kebolehkesanan dos radiasi minimum (MDD) dan kebergantungan kepada saiz medan dan tenaga. Penyinaran ini telah dijalankan di Unit Radioterapi, Insititut Perubatan dan Pergigian Termaju (IPPT) dengan menggunakan pemecut linear Elekta Synergy^® dengan tenaga pancaran elektron iaitu 6-, 9-, 12- dan 15 MeV pada dos tertentu dengan penjulatan daripada 1 hingga 5 Gy. Isyarat pendar gerlap terma (TL) telah menunjukkan gerak balas dos yang linear terhadap julat dos, min kebolehulangan semula dengan pekali variasi (CV) lebih baik daripada 10% dan tidak bergantung kepada perbezaan saiz medan pada p > 0.05. Nilai kebolehkesanan dos radiasi minimum biasanya daripada 3.53 hingga 4.13 mGy. Kemerosotan isyarat yang minimum bagi gentian optik telah dilaporkan oleh pancaran elektron yang bertenaga 9 MeV pada hari yang ke-74.

Kata kunci: Gentian optik; kelinearan dos; pendar gerlap terma (TL)

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*Pengarang untuk surat-menyurat; email: noramaliza@upm.edu.my