## 3 Results
#### 3.1.1 Environmental Radiation Exposure in the \({}^{99m}\)Tc-MDP Bone Scintigraphy Workplaces  
The results from Figure 2 indicate that the \({}^{99m}\)Tc-MDP bone scintigraphy procedure maintains a high level of safety, with environmental radiation exposure being generally low across most procedural steps. Notable exceptions occur during patient administration and imaging. During labeling, quality control, and syringe preparation tasks, radiation exposure remains relatively low, with mean effective doses ranging from 0.27 uSv/h to 0.9 uSv/h and minimal variability between cases. These findings suggest that exposure is well-controlled during these steps, likely due to shielding, adherence to safety protocols, and brief exposure times. In contrast, the patient administration step shows a significantly higher mean dose of 1.24 uSv/h, indicating that exposure levels during this phase can fluctuate based on factors such as the proximity of personnel to the patient and the duration of radiopharmaceutical injection. Furthermore, imaging exhibits the highest mean exposure at 3.7 uSv/h, which suggests that personnel may be exposed to increased radiation during patient positioning and scanning, with considerable differences depending on procedural and patient-specific factors. Despite this, radiation exposure during patient discharge remains low and consistent, with a mean dose of 0.45 uSv/h, reflecting effective exposure management in this phase. Figure 1: A personnel dose assessment was carried out to evaluate actual radiation exposure during the preparation and handling of \({}^{99m}\)Tc-MDP radiopharmaceuticals across different body parts. The assessment included Hp(0.07) measurements taken at (**A**) thumb, (**B**) index finger, (**C**) ring finger, (**D**) palm, (**E**) OSL Hp(0.07), (**F**) right lateral eye, (**G**) left lateral eye, (**H**) OSL Hp(3), and (**I**) Hp(10) whole body. The results of this study highlight the importance of robust radiation safety measures, particularly during the higher-risk phases of patient administration and imaging during \({}^{99\text{m}}\)Tc-MDP bone scintigraphy. Furthermore, by utilizing strategies such as minimizing the time spent near the patient, optimizing shielding, and additionally maintaining appropriate distancing from the radioactive source, all lead to reducing radiation exposure [34]. While most procedural steps result in low and controlled doses, greater attention should be paid to these higher-risk phases to ensure that personnel exposure remains within acceptable safety limits. A previous study found that 51% of patients who underwent \({}^{99\text{m}}\)Tc-MDP bone scintigraphy emitted high dose rates of \(\geq\)25 uSv/h, up to 49 uSv/h, at the posterior location at a distance of 30 cm [35]. 1.2 Assessment of Environmental Radiation Exposure in Nuclear Medicine Controlled Areas During \({}^{99\text{m}}\)Tc-MDP Bone Scintigraphy Procedure  
Figure 3 depicts the floor plan of the nuclear medicine department regulated zones, and Figure 4 provides the environmental ambient dose equivalent rates. It is crucial to note that the area above the \({}^{99\text{Mo}}\)/\({}^{99\text{m}}\)Tc generator recorded the highest dose rate of 600 uSv/h. This necessitates that staff working in the hot lab strictly adhere to the time restriction of no more than 2.4 min per hour near the \({}^{99\text{Mo}}\)/\({}^{99\text{m}}\)Tc generator, ensuring their safety and compliance with the 25 uSv/h occupational hourly dose rate limit [36]. Additionally, the environmental ambient dose equivalent rates for all restricted areas are shown in Figure 4. The working dose rate limit was determined based on the guidelines specified in ICRP Publication 75, General Principles for the Radiation Protection of Workers. Figure 2: Environmental radiation exposure in \({}^{99\text{m}}\)Tc-MDP bone scintigraphy workplaces during different steps: labeling, quality control, syringe preparation, patient administration, imaging, and patient discharge.