Radiotherapy phantoms are utilized to estimate radiation dose delivered to patients, and to improve the accuracy and measurement of radiation dosimetry. The aim of this research is to measure the percentage depth dose (PDD) using a locally designed and fabricated water phantom tank as a cost-effective alternative to the commercially available water phantom used for calibrating therapeutic radiation doses from a linear accelerator. Acrylic material was used to construct the 30 × 40 × 30 cm3 water tank, and tests were conducted on the fabricated phantom using the Elekta linear accelerator at the National Cancer Center Benghazi (NCCB). An IBA FC65-P ionization chamber was used to measure the dose at depths ranging from 0 to 16 cm in 1 cm intervals for 6 MV photon energy at 10 x 10 cm2 field size, and 100 cm source surface distance (SSD). The results indicated that the dose values obtained from the locally fabricated water phantom closely matched those from the commercially installed water phantom and were consistent with values reported in the literature.

Due to the complexity of radiotherapy techniques, rigorous Patient-Specific Quality Assurance (PSQA) is crucial to ensure the accuracy of treatment plans. This study aims to evaluate the performance of the Treatment Planning System (TPS) by comparing its dose distribution calculations with those obtained from the PRIMO Monte Carlo simulation. Treatment plans for 3D-CRT, IMRT, and VMAT were generated for a Rando breast phantom using the TPS. Subsequently, the dose distributions from the TPS were compared with those obtained from the PRIMO Monte Carlo simulation. Key metrics, including Homogeneity Index (HI) and Conformity Index (CI), were calculated to assess the quality of dose distribution. Furthermore, the dose constraints on OARs were evaluated to assess the impact on surrounding healthy tissues. To further validate the TPS, dose distributions from the linac log file (Dynalog) for VMAT were reconstructed within the PRIMO environment. These reconstructed distributions were then compared with the dose distributions calculated directly by the TPS. Gamma index analysis was employed to evaluate the agreement between these two sets of data. The comparison between TPS and Monte Carlo simulations revealed that 3D-CRT plans exhibited smaller deviations in HI and CI compared to IMRT and VMAT plans. However, a significant improvement in HI and CI values was observed in both IMRT planning simulations and Dynalog VMAT file simulations, indicating enhanced plan quality. The dose received by OARs in all treatment plans remained within the acceptable dose thresholds, demonstrating effective sparing of surrounding healthy tissues. For the PSQA procedure, the 3D-CRT technique is still the safest due to its lower level of complexity compared to IMRT and VMAT. More complex treatments should consider the robustness of treatment transfer information from TPS to linac to avoid dosimetry errors.

Positron Emission Tomography and Computed Tomography (PET/CT), a key imaging modality in nuclear medicine, Combines Anatomical (CT) and functional (PET) data for cancer diagnosis. Despite advancements in machine learning for automated medical image analysis, publicly available PET/CT datasets remain scarce, limiting Artificial Intelligence (AI) research compared to CT and MRI. This study built a publicly accessible PET/CT Vietnamese dataset for Non-Small Cell Lung Cancer (NSCLC). A total of 416 PET/CT scans were collected from three Vietnamese hospitals, including 300 NSCLC cases. Malignant FDG-sensitive lesions, identified via clinical PET/CT reports, were manually segmented in 3D (slice-by-slice) on PET images and validated by three experienced radiologists. The dataset includes both original and annotated DICOM files, along with clinical patient data. It achieved a dice similarity coefficient of 80.3 % and volume similarity of 81.9 %, demonstrating high segmentation accuracy comparable to other studies. This dataset supports AI-driven NSCLC research and contributes to global efforts in automated PET/CT analysis for nuclear medicine applications.

Natural materials that can cause increased radiation exposure to the surrounding environment are called Naturally Occurring Radioactive Materials (NORM). NORM contains uranium and thorium, critical elements with strategic and economic value. Conventional separation methods include chemical leaching and partial precipitation with strong acids and bases. These methods require large costs and produce waste harmful to the environment. This study explores bioleaching as an efficient and eco-friendly alternative to address these limitations. The indigenous bacteria used in bioleaching were isolated directly from NORM in Mamuju. This study aims to isolate, select, and evaluate bacteria from NORM as potential bioleaching agents. The methodology of this study includes NORM characterization, bacterial isolation and selection, molecular identification, and resistance testing of selected bacteria. The study successfully isolated eight bacterial strains from NORM, among which isolate L0A demonstrated the highest bioleaching potential. After five days of incubation, L0A achieved uranium and thorium concentrations of 2.508 mg/L and 10.5946 mg/L, respectively. Molecular identification revealed that L0A belongs to Bacillus sp. These findings demonstrate the potential of Bacillus sp. L0A is a bioleaching agent, paving the way for developing efficient, sustainable, and environmentally friendly methods for extracting valuable radioactive elements from NORM.

High-density fuel can increase the operating cycle of a nuclear reactor. The G.A. Siwabessy Multipurpose Reactor (RSG-GAS) is a research reactor owned by Indonesia that currently uses 19.75 % enriched uranium silicide fuel (U3Si2-Al) with a uranium density of 2.965 grU/cc. Previous studies have shown that high-density fuel, 4.8 grU/cc, can be used in the RSG-GAS core to extend the operating cycle. Previous studies related to high-density fuel conversion scenarios included a temporary conversion process to a density of 3.55 grU/cc before being increased to 4.8 grU/cc. However, the previous conversion process requires the addition of control rods to suppress the excess reactivity of the RSG-GAS. The current study focuses on determining the configuration of burnable poison wire for the standard fuel element of RSG-GAS (FE) made of cadmium and hafnium to suppress the reactivity (k-inf) of the 4.8 grU/cc fuel element so it could have an initial reactivity closer to the 2.965 grU/cc fuel. 5 pairs of 0.4 mm diameter Cd-wire coated with 0.1 mm AlMg2 cladding can suppress the reactivity of the fuel assembly, while 7 pairs of 0.8 mm diameter Hf-wire without cladding could suppress reactivity longer. The temperature coefficient of reactivity for the moderator temperature (MTC) and fuel temperature (FTC) also becomes more negative in high-density FE RSG-GAS while the amount of Pu-239 produced increases in high-density fuel element.

The utilization of X-rays in the Computed Tomography Scaner (CT scan) modality has proliferated for diagnostic purposes. CT scans deliver higher doses than other modalities, consequently protecting patients from excessive radiation doses is necessary by increasing optimization efforts in patients, especially pediatric patients. This research aims to determine the typical value and analyze the correlation of age, body mass, and exposure factor (mAs) to Computed Tomography Dose Index Volume (CTDIVol) and Dose Length Product (DLP). The typical dose value was obtained from the median value (Q2) using data derived from pediatric patients undergoing a head CT scan with a total of 33 patients at Universitas Andalas Hospital, with a correlation determined using a linearity test. The results obtained were the typical value for CTDIVol of 31.1 mGy and DLP of 793.3 mGy.cm. There is a moderate correlation between age and CTDIVol and DLP values, a high correlation between body mass and CTDIVol and DLP values, and a very high correlation between the exposure factor (mAs) and CTDIVol and DLP values.

Niger's uranium deposits are located in the north, bordering the southern Sahara. Mining activities led to the creation of the town of Arlit in 1969. Uranium mining and uranate production generate large volumes of radioactive solid and liquid tailings, as well as radioactive gases. Through dispersion and transport, these radioactive discharges become a source of contamination to the environment and food chain. The aim of our work is to assess the additional ambient exposure to radioactivity of surrounding populations as a result of mining activities. We assessed the risk of exposure to radionuclides from the uranium-238 decay chain through soil and certain building materials. The methodology used is based on collection of soil, sand, gravel and mud samples, which are analyzed using gamma spectrometry technique. Nine (9) public sites and five (5) building materials quarries were sampled for the work. The radiological parameters calculated are radium equivalent activity (Raeq), absorbed dose rate (D), internal and external risk indices (Hin and Hex) and gamma index (Iγ). For the whole study area, the calculated Raeq values range from 78.67 Bq/kg to 199.32 Bq/kg. These values are below the guideline value of 370 Bq/kg. In terms of air dose rate, however, the average value found was 0.32 mSv/year for the nine public sites considered. This exceeds the threshold value of 0.29 mSv/year corresponding to the selected exposure scenarios. In addition, in the mud (Quarry 5) and the second gravel quarry (Quarry 4), Iγ values greater than unity were found. A comparison is made with the results of similar studies around the world. Interpretation of the data obtained concludes that there is a risk of radiological overexposure at six (6) sites and two (2) quarries. This work is independent research which sheds new light on the issue of uranium mining activities impact on the environment in Arlit.

Purpose: This study aims to investigate the characteristics of photon beams from TrueBeam STx, comparing flattening filter (FF) and flattening filter free (FFF) configurations between measurements and Monte Carlo simulation. Instruments and methods: The Geant4/GATE simulation toolkit was utilized to simulate percentage depth dose (PDD), off-axis distance profiles (profiles), dmax, TPR20/10, surface dose, field size, penumbra, flatness, and symmetry. Subsequently, these simulated results were compared with experimental measurements and evaluated using the gamma index method. Results: There was a good agreement between simulation and experimental measurement results in modeling the PDD and profile of photon beams. All gamma passing rate indices exceeded 97 %, 94 %, and 90 % with criteria of 3 % and 3 mm, 2 % and 2 mm, and 1 % and 1 mm, respectively. The calculated results of beam characteristics (dmax, TPR20/10, surface dose, field size, penumbra, flatness, and symmetry) were highly compatible with experimental measurements, with discrepancies less than 3 %, except for the surface dose of the 6MV FF photon beam, which had an error of 3.83 %. Conclusion: The Geant4/GATE simulation toolkit provided accurate results for simulating and investigating photon beam characteristics, aligning closely with experimental measurements.

Research Gap: Neutron Capture Therapy (NCT) represents a cutting-edge neutron-therapy technique for tumor treatment, but there is a gap in understanding the optimization of neutron dose deposition in tumor cells, particularly in tissues enriched with boron and gadolinium. Research Objective: This study aims to evaluate the dose deposited by thermal neutrons in adipose tissues enriched with boron and gadolinium, utilizing the Monte Carlo Fluka code. Research Methodology: The research employs Fluka, an open source Monte Carlo simulations to assess thermal neutron dose deposition in tissues. The focus is on boron and gadolinium-enriched tissues to understand their impact on neutron dose optimization. Results: Findings affirm the advantages of boron and gadolinium in enhancing neutron dose deposition within tissues. Fluka simulations demonstrate the strategic utilization of neutron properties, showcasing the potential for improved tumor management. The study highlights gadolinium's attractiveness, suggesting its promising application in clinical settings.

Analysis of radiation contamination levels has been carried out using an Atomtex surveymeter in the patient rooms after thyroid cancer ablation therapy, in the Nuclear Medicine Installation, Abdoel Wahab Sjahranie Hospital. This study aims to measure the level of radiation exposure based on the rate of radiation exposure and radiation contamination of objects in the patient rooms after ablation therapy, and to find out how long linen can be washed since the first measurement. Data collection was carried out once a week, on the same weekday, for five weeks for objects in the patient rooms by using the surveymeter at a fixed distances from the objects’ surfaces. Radiation contamination measurements for linen items were carried out for 3 d by aiming the surveymeter to container containing linen items from certain distances. Based on this study, the level of radiation exposure obtained is categorized as low because the value range is below 10 μSv/h. The radiation contamination for some objects are categorized as low-level exposure because the value is less than 3.7 Bq/cm2. Other objects tend to be in the moderate-level category because the value is more than 3.7 Bq/cm2 and less than 37 Bq/cm2. The values obtained refer to the standard issued by BATAN. It can be concluded that the patient rooms in the Nuclear Medicine Installation of Abdoel Wahab Sjahranie Hospital are safe.