• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.327-333
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• 2023

In Order to Diagnose Maxillary Bone and Maxillary Sinus in the X-Ray Paranasal Sinus Projection test, this Study used Skull Rando Phantom to Change the Posture and X-ray tube Angle to 5° of the Head or 5° of ROC Who worked for more than 10 years. The Significance of the Evaluated score was Verified through SPSS Ver. 3.0, and the Cronbach value was Significantly higher at 0.712. In addition, as a Result of Calculating SNR by Setting the ROI(Receiver Operation Characteristic) of the Maxillary bone and Maxillary sinus images, it was the Highest at 6,449 in the Examination by tilting 5° toward the Head or Leg of the X-ray tube. In the study, it is believed that among the X-Ray simple Paranasal Sinus projection tests, a sharp Image can be Obtained during the Examination by Tilting the X-ray tube 5° toward the Head or Leg.

• Progress in Medical Physics
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• v.35 no.1
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• pp.10-15
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• 2024

Purpose: This study aimed to comprehensively investigate the diverse characteristics of a novel commercial bolus, CLEANBOLUS-WHITE (CBW), to ascertain its suitability for clinical application. Methods: The evaluation of CBW encompassed both physical and biological assessments. Physical parameters such as mass density and shore hardness were measured alongside analyses of element composition. Biological evaluations included assessments for skin irritation and cytotoxicity. Dosimetric properties were examined by calculating surface dose and beam quality using a treatment planning system (TPS). Additionally, doses were measured at maximum and reference depths, and the results were compared with those obtained using a solid water phantom. The effect of air gap on dose measurement was also investigated by comparing measured doses on the RANDO phantom, under the bolus, with doses calculated from the TPS. Results: Biological evaluation confirmed that CBW is non-cytotoxic, nonirritant, and non-sensitizing. The bolus exhibited a mass density of 1.02 g/cm³ and 14 shore 00. Dosimetric evaluations revealed that using the 0.5 cm CBW resulted in less than a 1% difference compared to using the solid water phantom. Furthermore, beam quality calculations in the TPS indicated increased surface dose with the bolus. The air gap effect on dose measurement was deemed negligible, with a difference of approximately 1% between calculated and measured doses, aligning with measurement uncertainty. Conclusions: CBW demonstrates outstanding properties for clinical utilization. The dosimetric evaluation underscores a strong agreement between calculated and measured doses, validating its reliability in both planning and clinical settings.

• Progress in Medical Physics
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• v.23 no.1
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• pp.48-53
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• 2012

The pencil beam convolution (PBC) algorithms in radiation treatment planning system have been widely used to calculate the radiation dose. A new photon dose calculation algorithm, referred to as the anisotropic analytical algorithm (AAA), was released for use by the Varian medical system. The aim of this paper was to investigate the difference in dose calculation between the AAA and PBC algorithm using the intensity modulated radiation therapy (IMRT) plan for lung cancer cases that were inhomogeneous in the low density. We quantitatively analyzed the differences in dose using the eclipse planning system (Varian Medical System, Palo Alto, CA) and I'mRT matirxx (IBA, Schwarzenbruck, Germany) equipment to compare the gamma evaluation. 11 patients with lung cancer at various sites were used in this study. We also used the TLD-100 (LiF) to measure the differences in dose between the calculated dose and measured dose in the Alderson Rando phantom. The maximum, mean, minimum dose for the normal tissue did not change significantly. But the volume of the PTV covered by the 95% isodose curve was decreased by 6% in the lung due to the difference in the algorithms. The difference dose between the calculated dose by the PBC algorithms and AAA algorithms and the measured dose with TLD-100 (LiF) in the Alderson Rando phantom was -4.6% and -2.7% respectively. Based on the results of this study, the treatment plan calculated using the AAA algorithms is more accurate in lung sites with a low density when compared to the treatment plan calculated using the PBC algorithms.

• The Journal of the Korea Contents Association
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• v.12 no.5
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• pp.303-310
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• 2012

In radiotherapy, accurate patient positioning and set up are important factor that treatment can influence success. In generally, the 3-laser system is used when the patient set up. But today the body surface scanning system(C-Rad system) is trying to use. Compare and evaluate the C-Rad system and the 3-laser system to check availability. Head and neck that are no movement of internal organs and easy to apply fixation device are limited. Alderson Rando anthropomorphic phantom and 10 patients who have lesions of head and neck are targeted. C-RAD system's setup error mean and standard deviation are the X axis($0.55{\pm}0.51mm$), Y axis($-0.2mm{\pm}0.523mm$), Z axis($-0.85{\pm}0.587mm$) in the phantom study, and in the patient study X axis($-0.05{\pm}0.621mm$), Y axis($0.075{\pm}0.755mm$) Z axis($-1.025{\pm}0.617mm$). So C-RAD system is better than 3-laser system mostly, but C-RAD system's error rate is a little worse than 3-laser system in the Z axis. When radiation treatment of head and neck, body surface contour scanning system contribute to correct positioning and minimize the set up error.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.247-253
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• 2013

The purpose is a comparative evaluation in the DR System according to the dosimetry and image quality of the quantitative and objective via Direct digital radiography, Indirect digital radiography, Image intensifier (Charge Coupled Device type) digital radiography. The experimental method used rando phantom and measured the entrance surface dose. And through using the measured entrance surface dose and then using the PCXMC program were evaluated risk due to irradiation and the effective dose. SNR and NPS and CNR were measured and analyzed by using 21cm acryl phantom. Significance of measured value was evaluated by statistics method. Entrance surface dose, major organ dose, effective dose all of them were measured the lowest rated in direct DR when it is on the basis of direct DR dose, high-dose ratio were measured in I.I DR approximately 1.3 times, indirect DR approximately 2.4 times. Risk in accordance with radiation also was measured same as dose ratio. On the conclusion that SNR measurement result based on direct DR SNR measurements, low-SNR ratio were measured in I.I DR approximately 7.25 times, indirect DR approximately 1.48 times. On the conclusion that CNR measurement result based on direct DR CNR measurements, high-dose ratio were measured in I.I type DR approximately 1.16 tims and low-dose ratio were measured in indirect DR approximately 0.87 times. Therefore Direct DR system using a-selenium sensing element to detect x-ray photon is thought effectively at the examination such as infant to sensitive irradiation and the genital gland. Because quality image is built by low dose. Also when it is necessary that image test requiring many diagnosis information, indirect DR system is thought effectively.

• Journal of the Korean Society of Radiology
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• v.15 no.3
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• pp.329-336
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• 2021

The Study studied the Inspection Method of Images to obtain a sharp image of the Costume among the bones Composed of Thoracic Using the Thoracic Cage Rando Phantom. At 80 cm of the phantom Distance at the X-ray tube focus, the position of the Phantom was Examined by Changing the Rt and Lt Posterior Oblique(LAO) and Rt and Lt Posterior Postero Oblique positions by 20°, 25° and 30°. The acquired images were Subjectively Evaluated by the Radiographer, and the Evaluation data were analyzed as SPSS ver. 3.0. The signal-to-noise ratio (SNR) was Calculated using the ImageJ Program. As a result, the Cronbach Alpha value was Significantly higher at 0.789. The results of the Signal-to-Noise Ratio (SNR) were high at 20° to 6.038 in the right posterior Transcription Direction at the time of Examination and 7.860, in the Supine Position, for images of Sternum bones. In conclusion, it is Believed that the patient position can be obtained from the Right Anterior Oblique(RAO) Position 20° if the X-ray technique is used to obtain the Sternum's advanced image, and the Left Anterior Oblique(LAO) Position 25° when filming in the Rght lying position.

• Journal of the Korean Society of Radiology
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• v.13 no.7
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• pp.979-986
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• 2019

The purpose of this study devised a method for the examination of the images of the first and second rib fractures of the axillary using Rib Rando Phantom. The position of the phantom and the angle of the X-ray tube were changed to vertical, head 5° and foot 5°. The Radiological Technologists subjectively evaluated the acquired images and the evaluation data were analyzed by SPSS 3.0 ver. The signal to noise ratio(SNR) was calculated using the ImageJ Program. As a result, the cronbach alpha value was significantly higher at 0.789. The SNR was highest at 6.038 when the X-ray tube was tilted 5° toward the head in the front of the ribs and highest at 7.860 when the X-ray tube was tilted 5° toward the foot. Radiographic Techniques proposed axillary ribs this study are as follows. The anterior rib scan is examined by elevating the fractured area and changing the X-ray tube angle by 5° towards the head. The posterior ribs scan is examined by attaching the fractured area and changing to the X-ray tube angle by 5° towards the foot. It is considered that such an inspection method can obtain a sharp image.

• Progress in Medical Physics
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• v.20 no.3
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• pp.152-158
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• 2009

Total Skin Electron Beam Therapy (TSEBT) of linear accelerator has become use so as to be useful, 2~9 MeV of energy territories came to be used with mycosis fungoides and cutaneous lymphomas in the superficial lesion treatment which covers the major portion of the body. I treat a patient to Stanford technique in this study, and it is $60^{\circ}$ around the patients whom Stanford technique irradiated electronic beam to a linear accelerator in horizontal directions and there is a way a standard of TSEBT treat it to six located field (anterior, posterior, and four obliques) becoming. An each field does horizontally it and consist to beam of the two component which fitted the center to a suitable angle. a patient treats it to three dual field a day in order to make short treatment time. when a first day, we treat one dual field at anterior position and two dual field at posterior position. when the second day, treat one dual field at posterior position and two dual field at anterior position. Therefore, six dual field is finished in perfect periodic two days. we made cylindrical acrylic phantom, and I inserted a dosimeter film between phantom. in order to measure a dose distribution calculation before treat a patient, and a patient checked it in six field directions that got from a treatment. It is after that thermoluminescent dosimetry (TLD) as it uses Rando phantom and then measurement dose distribution in six field directions after attaching at chest, the right and left flank, a back after irradiation.

• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.843-849
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• 2022

In this study, the probability of secondary carcinogenesis was analyzed by measuring the exposure dose of surrounding normal organs during radiosurgery using a gamma knife. A pediatric phantom (Model 706-G, CIRS, USA) composed of human tissue-equivalent material was set to four tumor volumes of 0.25 cm³, 0.51 cm³, 1.01 cm³, and 2.03 cm³, and the average dose was 18.4 ± 3.4 Gy. After installing the Rando phantom on the table of the gamma knife surgical equipment, the OSLD nanoDot dosimeters were placed in the right eye, left eye, thyroid, thymus gland, right lung, and left lung to measure each exposure dose. The probability of cancer occurrence due to radiation exposure of surrounding normal organs during gamma knife radiosurgery for acoustic schwannoma disease was 4.08 cancers per 100,000 at a tumor volume of 2.03 cm³. This study is expected to be used as useful data in relation to stochastic effects in the future by studying the risk of secondary radiation exposure that can occur during stereotactic radiosurgery.

• Progress in Medical Physics
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• v.23 no.1
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• pp.62-69
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• 2012

The dose re-calculation process using Megavoltage cone-beam CT images is inevitable process to perform the Adaptive Radiation Therapy (ART). The purpose of this study is to improve dose re-calculation accuracy using MVCBCT images by applying intensity calibration method and three dimensional rigid body transform and filtering process. The three dimensional rigid body transform and Gaussian smoothing filtering process to MVCBCT Rando phantom images was applied to reduce image orientation error and the noise of the MVCBCT images. Then, to obtain the predefined modification level for intensity calibration, the cheese phantom images from kilo-voltage CT (kV CT), MVCBCT was acquired. From these cheese phantom images, the calibration table for MVCBCT images was defined from the relationship between Hounsfield Units (HUs) of kV CT and MVCBCT images at the same electron density plugs. The intensity of MVCBCT images from Rando phantom was calibrated using the predefined modification level as discussed above to have the intensity of the kV CT images to make the two images have the same intensity range as if they were obtained from the same modality. Finally, the dose calculation using kV CT, MVCBCT with/without intensity calibration was applied using radiation treatment planning system. As a result, the percentage difference of dose distributions between dose calculation based on kVCT and MVCBCT with intensity calibration was reduced comparing to the percentage difference of dose distribution between dose calculation based on kVCT and MVCBCT without intensity calibration. For head and neck, lung images, the percentage difference between kV CT and non-calibrated MVCBCT images was 1.08%, 2.44%, respectively. In summary, our method has quantitatively improved the accuracy of dose calculation and could be a useful solution to enhance the dose calculation accuracy using MVCBCT images.