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Measurement of radiation attenuation parameters of modified defatted soy flour-soy protein isolate-based mangrove wood particleboards to be used for CT phantom production

Samson DO, Jafri MZM, Shukri A, Hashim R, Sulaiman O, Aziz MZA, et al.

Radiat Environ Biophys, 2020 08;59(3):483-501.
PMID: 32333105 DOI: 10.1007/s00411-020-00844-z

For the first time, Rhizophora spp. (Rh. spp.) particleboard phantoms were developed using defatted soy flour (DSF) and soy protein isolate (SPI) modified by sodium hydroxide and itaconic acid polyamidoamine-epichlorohydrin (IA-PAE) adhesive. The microstructural characterization and X-ray diffraction patterns of the material revealed that the modified DSF and SPI adhesives became more compact and homogeneous when NaOH/IA-PAE was added, which prevented damage by moisture. It was confirmed that the composite is crystalline with (101), (002), and (004) orientations. Phantoms made of this material were scanned with X-ray computed tomography (CT) typically used for abdominal examinations with varying energies corresponding to 80, 120, and 135 kVp, to determine CT numbers, electron densities, and density distribution profiles. The radiation attenuation parameters were found to be not significantly different from those of water (XCOM) with p values [Formula: see text] 0.05 for DSF and SPI. The DSF- and SPI-based particleboard phantoms showed CT numbers close to those of water at the three X-ray CT energies. In addition, electron density and density distribution profiles of DSF-SPI-Rh. spp. particleboard phantoms with 15 wt% IA-PAE content were even closer to those of water and other commercial phantom materials at the three X-ray CT energies. It is concluded that DSF-SPI with NaOH/IA-PAE added can be used as a potential adhesive in Rh. spp. particleboard phantoms for radiation dosimetry.
Characterization of soy-lignin bonded Rhizophora spp. particleboard as substitute phantom material for radiation dosimetric studies - Investigation of CT number, mass attenuation coefficient and effective atomic number

Zuber SH, Hashikin NAA, Mohd Yusof MF, Aziz MZA, Hashim R

Appl Radiat Isot, 2021 Apr;170:109601.
PMID: 33515930 DOI: 10.1016/j.apradiso.2021.109601

Experimental particleboards are made from Rhizophora spp. wood trunk with three different percentages of lignin and soy flour (0%, 6% and 12%) as adhesives. The objective was to investigate the equivalence of Rhizophora spp. particleboard as phantom material with human soft tissue using Computed Tomography (CT) number. The linear and mass attenuation coefficient of Rhizophora spp. particleboard at low energy range was also explored using X-ray Fluorescence (XRF) configuration technique. Further characterization of the particleboard was performed to determine the effective atomic number, Zeff using Energy Dispersive X-Ray (EDX) method. Adhesive-bonded Rhizophora spp. particleboard showed close similarities with water, based on the average CT numbers, electron density calibration curve and the analysis of CT density profile, compared to the binderless particleboard. The effective atomic number obtained from the study indicated that the attenuation properties of all the particleboards at different percentages of adhesives were almost similar to water. The mass attenuation coefficient calculated from XRF configuration technique showed good agreement with water from XCOM database, suggesting its potential as phantom material for radiation study.
Fulltext Influence of Different Percentages of Binders on the Physico-Mechanical Properties of Rhizophora spp. Particleboard as Natural-Based Tissue-Equivalent Phantom for Radiation Dosimetry Applications

Zuber SH, Hashikin NAA, Yusof MFM, Aziz MZA, Hashim R

Polymers (Basel), 2021 Jun 04;13(11).
PMID: 34199810 DOI: 10.3390/polym13111868

Rhizophora spp. particleboard with the incorporation of lignin and soy flour as binders were fabricated and the influence of different percentages of lignin and soy flour (0%, 6% and 12%) on the physico-mechanical properties of the particleboard were studied. The samples were characterised by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray fluorescence (XRF) and internal bonding. The results stipulated that the addition of binders in the fabrication of the particleboard did not change the functional groups according to the FTIR spectrum. For XRD, addition of binders did not reveal any major transformation within the composites. SEM and EDX analyses for all percentages of binders added showed no apparent disparity; however, it is important to note that the incorporation of binders allows better bonding between the molecules. In XRF analysis, lower percentage of chlorine in the adhesive-bonded samples may be advantageous in maintaining the natural properties of the particleboard. In internal bonding, increased internal bond strength in samples with binders may indicate better structural integrity and physico-mechanical strength. In conclusion, the incorporation of lignin and soy flour as binders may potentially strengthen and fortify the particleboard, thus, can be a reliable phantom in radiation dosimetry applications.
Fulltext Palliative brachytherapy to axilla and hypopharynx in elderly patient with hypopharyngeal squamous cell carcinoma - case report

Appalanaido GK, Shukor SA, Fan AS, Chong SE, Hussin H, Karim NKA, et al.

Rep Pract Oncol Radiother, 2021;26(4):647-653.
PMID: 34434581 DOI: 10.5603/RPOR.a2021.0076

Brachytherapy (BT) is an important local treatment of tumor and it can be applied to different anatomical sites either in a curative or palliative setting. BT can deliver large dose of radiation to the tumor while sparing the surrounding normal tissue which translates into a better therapeutic ratio compared to external beam radiotherapy. However, the evidence for the use of brachytherapy in the palliative setting is lacking in the literature. In this case report, we describe the brachytherapy technique and outcome of a patient with squamous cell carcinoma of the hypopharynx who underwent palliative brachytherapy to the hypopharynx and metastatic tumor at the right axilla.
Radiological and Dosimetric Evaluation of Biomaterial Composite Phantoms with High Energy Photons and Electrons

Samson DO, Aziz MZA, Shukri A, Mat Jafri MZ, Hashim R, Zuber SH, et al.

Health Phys, 2023 Aug 01;125(2):77-91.
PMID: 36826380 DOI: 10.1097/HP.0000000000001688

The current study was undertaken to investigate the radiological and dosimetric parameters of natural product-based composite (SPI/NaOH/IA-PAE/ Rhizophora spp .) phantoms. The radiological properties of the phantoms were measured at different gamma energies from Compton scatter of photons through angles of 0, 30, 45, 60, 75, and 90 degrees. Ionization chamber (IC) and Gafchromic EBT3 film dosimeters were employed to evaluate the dosimetric characteristics for photons (6-10 MV) and electrons (6-15 MeV). Radiological property results of the composite phantoms were consistent with good quality compared to those of solid water phantoms and theoretical values of water. Photon beam quality index of the SPI15 phantom with p-values of 0.071 and 0.073 exhibited insignificant changes. In addition, good agreement was found between PDD curves measured with IC and Gafchromic EBT3 film for both photons and electrons. The computed therapeutic and half-value depth ranges matched within the limits and are similar to those of water and solid water phantoms. Therefore, the radiological and dosimetric parameters of the studied composite phantom permit its use in the selection of convenient tissue- and water-equivalent phantom material for medical applications.
Fulltext Dosimetric Analysis of Rhizophora-based Phantom Material in Radiation Therapy Applications Using Monte Carlo GATE Simulation

Zuber SH, Hadi MFRA, Samson DO, Jayamani J, Rabaiee NA, Aziz MZA, et al.

J Med Phys, 2023;48(4):358-364.
PMID: 38223797 DOI: 10.4103/jmp.jmp_75_23

PURPOSE: This study aims to determine the percentage depth dose (PDD) of a phantom material made from soy-lignin bonded Rhizophora spp. particleboard coated with a gloss finish by using Monte Carlo Geant4 Application for Tomographic Emission (GATE) simulation.
MATERIALS AND METHODS: The particleboard was fabricated using a hot pressing technique at target density of 1.0 g·cm-3 and the elemental fraction was recorded for the simulation. The PDD was simulated in the GATE simulation using the linear accelerator Elekta Synergy model for the water phantom and Rhizophora phantom, and the results were compared with the experimental PDD performed by several studies. Beam flatness and beam symmetry were also measured in this study.
RESULTS: The simulated PDD for Rhizophora and water was in agreement with the experimental PDD of water with overall discrepancies of 0% to 8.7% at depth ranging from 1.0 to 15.0 cm. In the GATE simulation, all the points passed the clinical 3%/3 mm criterion in comparison with water, with the final percentage of 2.34% for Rhizophora phantom and 2.49% for the water phantom simulated in GATE. Both the symmetries are all within the range of an acceptable value of 2.0% according to the recommendation, with the beam symmetry of the water phantom and Rhizophora phantom at 0.58% and 0.28%, respectively.
CONCLUSIONS: The findings of this study provide the necessary foundation to confidently use the phantom for radiotherapy purposes, especially in treatment planning.