RADIATION PROTECTION CONFERENCE AND WORKSHOP 2023
MESYUARAT AGUNG TAHUNAN (AGM) ke-22
- BUKU LAPORAN AGM ke-22 (Tahun 2023)
- MINIT MESYUARAT MARPA Bil. 1-2023
- MINIT MESYUARAT MARPA Bil. 2-2023
- MINIT AGM MARPA ke-21 (Tahun 2022)
- MINIT MESYUARAT MARPA Bil. 4-2022
IRPA ASF
- Light induced fading in optically stimulated luminescence dots for medical dosimetry measurement
For single point dose measurements, the use of optically stimulated luminescence dosimeters (OSLDs),nano Dots is gaining a remarkable interest due to availability and potential attributes. In this paper, new methods to optically anneal the nano Dot™ OSLDs were developed using five different light sources namely; 40 W purple ultra violet light (UV), 5 W white light-emitting diode (LED), 100 W tungsten-halogen lamp (THL), 14 W compact fluorescent lamp (CFL) and bright room office environment light (BRL) with temperatures of 35 ºC, 25 ºC, 30 ºC, 27 ºC and 24 ºC respectively. The OSL system performance was evaluated via intrinsic measurements to ascertain the precision of the micro Star reader. The reader stability evaluated from the dark current (DRK), CAL and LED counts were found to be 6.0 ± 0.9, 1677 ± 31, and 4657 ± 563, respectively, which were rightly below the control limits of 30 (DRK), and ± 10% of the mean (CAL and LED). The regeneration rate of the OSL signal during the optical annealing procedure revealed that 14 W CFL (Compact Fluorescent Lamp) gives the highest response with an average signal loss of ~93% in 60 minutes illumination time, compared to 92%, 90%, 87% and 44% signal loss using UV light, LED, THL, and BRL,
respectively.
Sumber : Ts. Dr. Ratna Suffhiyanni Omar - Dose assessment of 4- and 16-slice multi-detector computed tomography (MDCT) scanners
This paper reports the performance of an X-ray generator and the CT dosimetry of 4- and 16-slice Multi-Detector Computed Tomography (MDCT) scanners operating in the axial mode. Two types of CT scanners were evaluated; the 4-slice Toshiba Asteion 4 Edition and the 16-slice Siemen Somatom Emotion 16. The dose estimation for the X-ray generator and the MDCT of the scanners were assessed under certain parameters (kV, mA, and exposure time) using a multi-function detector (Raysafe Unfors), and nanoDot™ OSLDs. The weighted CT Dose Index (CTDIw) was measured using a 100 mm standard pencil beam ion chamber, and nanoDot™ OSLDs, in a 160 mm diameter head and 320 mm-diameter body cylindrical acrylic Polymethyl-Methacrylate (PMMA) phantom (160 mm length). The CTDIw values were specifified either according to the central axis or 10 mm from the 4 outer edges of the phantom. The two sizes of the phantoms based on the measurements of the CTDIw of the two CT scanners were compared.
The weighted CTDIs (CTDIw) were calculated and the CT X-ray generator performance observed. The results of the two difffferent types of detectors were examined and compared. The deviation ac curacy of the tube voltage was ± 5 kV or ± 5%, whichever is greater, whereas the accuracy of the tube potential (mA) was ± 10%. The radiation dose (CTDIw) for dosage under exceptional CT scanning conditions in the axial mode was observed to meet the manufacturer’s guidelines (< ± 20%). The implementation of the CT dosimetry steps ensured patient safety and is expected to reduce future risk in the case that an estimated dose value was inappropriately administered above the relevant threshold for any routine CT examination.
Sumber : Ts. Dr. Ratna Suffhiyanni Omar - Entrance surface dose of eyes and thyroid using nanoDot optically stimulated luminescence in 64-slices computed tomography scanner
Entrance surface dose (ESD) is used to estimate the patient exposure dose during X-ray computed tomography (CT) procedures. However, in a clinical practice the ESDs measurements remains challenging due to lack of suitable dosimeters. We demonstrated an anthropomorphic phantom ESDs assessment for both eyes and thyroids; left and right using Landauer nanoDot™ OSL dosimeters (OSLDs) during 64-slices CT scan examinations. 24 nanoDot™ OSLDs were randomly selected and placed within slices 1 to 9 of anthropomorphic phantom. The ESDs were measured through direct energies (80 140 kV) and variation of current value (minimum, middle and maximum) from CT scanner model Siemens Somatom Definition AS+. We found that this practical method using small OSLDs; have an outer width of 10 mm can measured a partial dose from selective CT protocols. The ESDs results for both eyes and thyroids from 2 different InLight Microstar OSL reader show that the doses increased by the changes of energies and current values.
For readout procedure using InLight Microstar OSL reader, standard measurement (in 30 days) evaluated from the dark current (DRK), CAL and LED counts were found rightly below the control limits of 30 (DRK), and ±10% of the mean (CAL and LED). In conclusion, nanoDot™ OSLDs is considered as potential candidate for direct measurement of entrance surface dose of patient.
Sumber : Ts. Dr. Ratna Suffhiyanni Omar
Persidangan ini telah dirasmikan oleh Ahli Majlis Mesyuarat Kerajaan Negeri Terengganu, YB Dr. Azman Ibrahim mewakili Menteri Besar Terengganu. Turut hadir pada majlis perasmian itu ialah Presiden MARPA iaitu Encik Mohd Sidek Othman.
Seramai 160 peserta yang terdiri daripada pihak industri, institut pengajian tinggi (IPT) dan agensi kerajaan menghadiri persidangan ini bagi mendapatkan maklumat terkini berkaitan cabaran dan amalan terbaik berhubung perlindungan sinaran di era pandemik Covid-19 selain mengukuhkan jalinan hubungan kerjasama dan profesional antara peserta.
Semoga program yang dirancang dapat berjalan dengan lancar. Jaga diri dan patuhi SOP sedia ada. Selamat bersidang semuanya.
Sumber :
Buat pertama kalinya Jabatan Tenaga Atom Malaysia (Atom Malaysia) berjaya menguruskan penghantaran instrumen pengesanan sinaran melalui *_Practical Arrangement on the Establishment of a Loaner Pool for Radiation Detection Equipment (Loaner Pool)_* antara Atom Malaysia dan International Atomic Energy Agency (IAEA) ke Qatar bersempena *Piala Dunia FIFA Qatar 2022* di Doha.
Malaysia amat berbangga dapat bekerjasama dengan IAEA melalui inisiatif ini dalam memastikan keamanan dan keselamatan di rantau Asia Pasifik khususnya dalam sekuriti nuklear terjamin. Usaha murni ini adalah bagi mengekang ancaman terrorism dan penyalahgunaan bahan radioaktif dan nuklear semasa acara global dunia seumpama ini.