## 2 Materials and Methods
Finally, reviewing the collected data and survey findings allows for the assessment of the protocol's effectiveness and the identification of areas for procedural adjustments. Anthropomorphic Phantom Study on the Dose-Response and Time Dependency of OSL Dosimeters in 99 mTc-MDP Bone Scintigraphy  
The equipment used in this study included nanoDot small-type optically stimulated luminescence (OSL) dosimeters (Landauer Inc., Glenwood, IL, USA) and Quixel OSL badges (Landauer Inc., Glenwood, IL, USA). Additionally, a Geiger-Mueller counter survey meter (Ludlum Measurements Inc., Sweetwater, TX, USA) was utilized, along with 99 mTc-MDP radiopharmaceuticaleticals, obtained from the Thailand Institute of Nuclear Technology (Thailand Institute of Nuclear Technology (Public Organization), Ongkarak, Nakornayok, Thailand). An RSD anthropomorphic head phantom with a complete cervical spine (C1-C7) was used for Hp(3) eye lens dosimetry at a depth of 3 mm. An rsd anthropomorphic thorax phantom was employed for Hp(10) whole-body personal dose equivalent at a tissue depth of 10 mm. An anthropomorphic hand phantom for shallow dosimetry (Universal Medical Inc., Oldsmar, FL, USA) was used for the skin, hands, and feet equivalent dose at 0.07 mm depth nominated as Hp(0.07). These phantoms facilitated the evaluation of time and dose-response dependencies of OSL dosimeters in 99 mTc-MDP bone scintigraphy. Nuclear medicine staff involved in 99 mTc-MDP procedures were personally monitored for occupational effective dose. Specifically, the following personnel were monitored throughout the preparation, administration, and diagnostic procedures involving 99 mTc-MDP: radiopharmaceuticals, nurses, radiological technologists' assistants, and radiological technologists. To measure the occupational effective dose of the nuclear medicine staff, a nanoDot OSL dosimeter and Inlight type OSL (Quixel) badges were used. The effective dose measurements were recorded at Hp(10) and Hp(0.07) for the skin, hands, and feet, and Hp(3) for the eye lens. The personal dose equivalent in soft tissue is represented by the symbol Hp(d), according to the International Commission on Radiation Units & Measurements (ICRU) standard [15; 16; 17]. To closely resemble the energy range used in nuclear medicine, a traceable 137 Cs (662 keV) source was used to calibrate the dosimeters. The calibration technique followed the rules specified by the Japanese OSL dosimeters Standards Association (JIS) Z 4345-3, which includes determining any uncertainty [18]. To simulate the body of a nuclear medicine staff, anthropomorphic phantoms were used [19]. For calibration, nanodot OSL dosimeters were positioned adjacent to each eye of the anthropomorphic head phantom to measure the equivalent dose at the eye lens at a depth of 3 mm, Hp(3). Additionally, to calibrate the whole-body equivalent effective dose, Hp(10), an OSL badge was positioned on the chest of the anthropomorphic thorax phantom. The nanodot OSL dosimeters were also placed on the anthropomorphic hand phantom's palm, thumb, index finger, and ring finger to match the Hp(0.07) equivalent dose, representing the skin dose on the hands, feet, and skin. Prior to the survey, Hp(10), Hp(3), and Hp(0.07) were assessed three times with a Microstar reader (Landauer, IL, USA) and an InLight dosimeter badge reader (Landauer, IL, USA). To ascertain the data point, the average measurement of the three non-irradiated nanoDot dosimeters was subtracted from the exposed dosimeter measurements [20]. The irradiated nanoDot dosimeter coefficients of variation (\(CV\)) were calculated by following Equation (1):  
\[CV(\%)=\left[ \begin{array}{c}SD\\ \overline{D_{ave}}\end{array} \right]\times 100 \tag{1}\]  
where \(SD\) is the recorded dose standard deviation of the dose recorded and the average exposure is \(D_{ave}\). The radiation dose coefficients of variance (\(Sv\)) are calculated by applying Equation (2). Applying the background environmental radiation values prior to the preparation and administration of 99 mTc-MDP.