1.Evaluating the Influence of Scan Timing on Dosimetric Accuracy in EBT3 and EBT4 Radiochromic Films
Jin Dong CHO ; Su Chul HAN ; Jason Joon Bock LEE ; Hyebin LEE ; Heerim NAM
Progress in Medical Physics 2024;35(4):135-144
Purpose:
This study compares the dosimetric properties of EBT3 and EBT4 GAFchromic films in transmission and reflection scanning modes, focusing on dose response, sensitivity, and postirradiation stability.
Methods:
The EBT3 and EBT4 films were irradiated at doses of 0–10 Gy using a Varian TrueBeam linear accelerator at 6 MV. The films were scanned at intervals between 1 and 336 hours after irradiation in both transmission and reflection modes. Net optical density (NetOD) values from each scan were used to evaluate dose response and sensitivity, with calibration curves created for each film and scan mode. Dose differences between calculated and delivered doses were assessed over time.
Results:
The EBT3 and EBT4 films exhibited similar dose–response curves and stable NetOD values across both scanning modes. However, EBT4 exhibited reduced sensitivity variability in response to dose changes. After irradiation, NetOD values increased up to 24 hours before stabilizing, suggesting that a 24-hour scan time is sufficient for consistent measurements. Dose differences between films and modes remained within ±4%.
Conclusions
EBT4 offers comparable dosimetric performance to EBT3, with additional benefits, such as improved dose–response linearity and reduced sensitivity fluctuations. The findings indicate that EBT4 can serve as a reliable successor to EBT3.
2.Evaluating the Influence of Scan Timing on Dosimetric Accuracy in EBT3 and EBT4 Radiochromic Films
Jin Dong CHO ; Su Chul HAN ; Jason Joon Bock LEE ; Hyebin LEE ; Heerim NAM
Progress in Medical Physics 2024;35(4):135-144
Purpose:
This study compares the dosimetric properties of EBT3 and EBT4 GAFchromic films in transmission and reflection scanning modes, focusing on dose response, sensitivity, and postirradiation stability.
Methods:
The EBT3 and EBT4 films were irradiated at doses of 0–10 Gy using a Varian TrueBeam linear accelerator at 6 MV. The films were scanned at intervals between 1 and 336 hours after irradiation in both transmission and reflection modes. Net optical density (NetOD) values from each scan were used to evaluate dose response and sensitivity, with calibration curves created for each film and scan mode. Dose differences between calculated and delivered doses were assessed over time.
Results:
The EBT3 and EBT4 films exhibited similar dose–response curves and stable NetOD values across both scanning modes. However, EBT4 exhibited reduced sensitivity variability in response to dose changes. After irradiation, NetOD values increased up to 24 hours before stabilizing, suggesting that a 24-hour scan time is sufficient for consistent measurements. Dose differences between films and modes remained within ±4%.
Conclusions
EBT4 offers comparable dosimetric performance to EBT3, with additional benefits, such as improved dose–response linearity and reduced sensitivity fluctuations. The findings indicate that EBT4 can serve as a reliable successor to EBT3.
3.Evaluating the Influence of Scan Timing on Dosimetric Accuracy in EBT3 and EBT4 Radiochromic Films
Jin Dong CHO ; Su Chul HAN ; Jason Joon Bock LEE ; Hyebin LEE ; Heerim NAM
Progress in Medical Physics 2024;35(4):135-144
Purpose:
This study compares the dosimetric properties of EBT3 and EBT4 GAFchromic films in transmission and reflection scanning modes, focusing on dose response, sensitivity, and postirradiation stability.
Methods:
The EBT3 and EBT4 films were irradiated at doses of 0–10 Gy using a Varian TrueBeam linear accelerator at 6 MV. The films were scanned at intervals between 1 and 336 hours after irradiation in both transmission and reflection modes. Net optical density (NetOD) values from each scan were used to evaluate dose response and sensitivity, with calibration curves created for each film and scan mode. Dose differences between calculated and delivered doses were assessed over time.
Results:
The EBT3 and EBT4 films exhibited similar dose–response curves and stable NetOD values across both scanning modes. However, EBT4 exhibited reduced sensitivity variability in response to dose changes. After irradiation, NetOD values increased up to 24 hours before stabilizing, suggesting that a 24-hour scan time is sufficient for consistent measurements. Dose differences between films and modes remained within ±4%.
Conclusions
EBT4 offers comparable dosimetric performance to EBT3, with additional benefits, such as improved dose–response linearity and reduced sensitivity fluctuations. The findings indicate that EBT4 can serve as a reliable successor to EBT3.
4.Evaluating the Influence of Scan Timing on Dosimetric Accuracy in EBT3 and EBT4 Radiochromic Films
Jin Dong CHO ; Su Chul HAN ; Jason Joon Bock LEE ; Hyebin LEE ; Heerim NAM
Progress in Medical Physics 2024;35(4):135-144
Purpose:
This study compares the dosimetric properties of EBT3 and EBT4 GAFchromic films in transmission and reflection scanning modes, focusing on dose response, sensitivity, and postirradiation stability.
Methods:
The EBT3 and EBT4 films were irradiated at doses of 0–10 Gy using a Varian TrueBeam linear accelerator at 6 MV. The films were scanned at intervals between 1 and 336 hours after irradiation in both transmission and reflection modes. Net optical density (NetOD) values from each scan were used to evaluate dose response and sensitivity, with calibration curves created for each film and scan mode. Dose differences between calculated and delivered doses were assessed over time.
Results:
The EBT3 and EBT4 films exhibited similar dose–response curves and stable NetOD values across both scanning modes. However, EBT4 exhibited reduced sensitivity variability in response to dose changes. After irradiation, NetOD values increased up to 24 hours before stabilizing, suggesting that a 24-hour scan time is sufficient for consistent measurements. Dose differences between films and modes remained within ±4%.
Conclusions
EBT4 offers comparable dosimetric performance to EBT3, with additional benefits, such as improved dose–response linearity and reduced sensitivity fluctuations. The findings indicate that EBT4 can serve as a reliable successor to EBT3.
5.Evaluating the Influence of Scan Timing on Dosimetric Accuracy in EBT3 and EBT4 Radiochromic Films
Jin Dong CHO ; Su Chul HAN ; Jason Joon Bock LEE ; Hyebin LEE ; Heerim NAM
Progress in Medical Physics 2024;35(4):135-144
Purpose:
This study compares the dosimetric properties of EBT3 and EBT4 GAFchromic films in transmission and reflection scanning modes, focusing on dose response, sensitivity, and postirradiation stability.
Methods:
The EBT3 and EBT4 films were irradiated at doses of 0–10 Gy using a Varian TrueBeam linear accelerator at 6 MV. The films were scanned at intervals between 1 and 336 hours after irradiation in both transmission and reflection modes. Net optical density (NetOD) values from each scan were used to evaluate dose response and sensitivity, with calibration curves created for each film and scan mode. Dose differences between calculated and delivered doses were assessed over time.
Results:
The EBT3 and EBT4 films exhibited similar dose–response curves and stable NetOD values across both scanning modes. However, EBT4 exhibited reduced sensitivity variability in response to dose changes. After irradiation, NetOD values increased up to 24 hours before stabilizing, suggesting that a 24-hour scan time is sufficient for consistent measurements. Dose differences between films and modes remained within ±4%.
Conclusions
EBT4 offers comparable dosimetric performance to EBT3, with additional benefits, such as improved dose–response linearity and reduced sensitivity fluctuations. The findings indicate that EBT4 can serve as a reliable successor to EBT3.
6.Subjective Experience on Virtual Reality-Assisted Mental Health Promotion Program
Hyebin KO ; Hyun Ju LIM ; Jeonghyun PARK ; Kyungwon KIM ; Hwagyu SUH ; Byung Dae LEE ; Young Min LEE ; Eunsoo MOON ; Du-Ri KIM ; Jong-Hwan PARK ; Myung-Jun SHIN ; Yean-Hwa LEE
Psychiatry Investigation 2024;21(4):380-386
Objective:
Mental health promotion programs using virtual reality (VR) technology have been developed in various forms. This study aimed to investigate the subjective experience of a VR-assisted mental health promotion program for the community population, which was provided in the form of VR experience on a bus to increase accessibility.
Methods:
Ninety-six people participated in this study. The relationship between the subjective experience and mental health states such as depression, anxiety, perceived stress, and quality of life was explored. The subjective experience on depression and stress before and after VR program treatment was compared using the Wilcoxon signed-rank test. The satisfaction with the VR-assisted mental health promotion program was examined after using the VR program.
Results:
The VR-assisted mental health promotion program on a bus significantly improved subjective symptoms such as depression (p=0.036) and perceived stress (p=0.010) among all the participants. Among the high-risk group, this VR program significantly relieved subjective depressive feeling score (p=0.033), and subjective stressful feeling score (p=0.035). In contrast, there were no significant changes in subjective depressive feelings (p=0.182) and subjective stressful feelings (p=0.058) among the healthy group. Seventy-two percent of the participants reported a high level of satisfaction, scoring 80 points or more.
Conclusion
The findings of this study suggest that the VR-assisted mental health promotion program may effectively improve the subjective depressive and stressful feelings. The use of VR programs on buses to increase of accessibility for the community could be a useful approach for promoting mental health among the population.
7.Small intestinal epiploic foramen entrapment in a seven-month pregnant Thoroughbred mare: a case report
Hyebin HWANG ; Seyoung LEE ; Kyung-won PARK ; Eun-bee LEE ; Taeyoung KANG ; Jong-pil SEO ; Hyohoon JEONG
Korean Journal of Veterinary Research 2023;63(2):e11-
A seven-month pregnant four-year-old Thoroughbred mare with colic weighing 600 kg was referred to the Jeju National University Equine Hospital. A physical examination and ultrasound suggested epiploic foramen entrapment. The patient underwent ileum resection and end-to-side jejunocecostomy. After surgery, the horse showed a consistent pain when introduced to feeding. A repeat laparotomy was performed to enlarge the stoma size with side-to-side jejunocecostomy. The repeat laparotomy was successful, and the mare gave birth uneventfully. This report describes a case of small intestinal epiploic foramen entrapment and the clinical outcomes of the 2 consecutive laparotomies a Thoroughbred mare in late gestation.
8.Convolutional Neural Network-Based Automatic Segmentation of Substantia Nigra on Nigrosome and Neuromelanin Sensitive MR Images
Junghwa KANG ; Hyeonha KIM ; Eunjin KIM ; Eunbi KIM ; Hyebin LEE ; Na-young SHIN ; Yoonho NAM
Investigative Magnetic Resonance Imaging 2021;25(3):156-163
Recently, neuromelanin and nigrosome imaging techniques have been developed to evaluate the substantia nigra in Parkinson’s disease. Previous studies have shown potential benefits of quantitative analysis of neuromelanin and nigrosome images in the substantia nigra, although visual assessments have been performed to evaluate structures in most studies. In this study, we investigate the potential of using deep learning based automatic region segmentation techniques for quantitative analysis of the substantia nigra. The deep convolutional neural network was trained to automatically segment substantia nigra regions on 3D nigrosome and neuromelanin sensitive MR images obtained from 30 subjects. With a 5-fold cross-validation, the mean calculated dice similarity coefficient between manual and deep learning was 0.70 ± 0.11. Although calculated dice similarity coefficients were relatively low due to empirically drawn margins, selected slices were overlapped for more than two slices of all subjects. Our results demonstrate that deep convolutional neural network-based method could provide reliable localization of substantia nigra regions on neuromelanin and nigrosome sensitive MR images.
9.Convolutional Neural Network-Based Automatic Segmentation of Substantia Nigra on Nigrosome and Neuromelanin Sensitive MR Images
Junghwa KANG ; Hyeonha KIM ; Eunjin KIM ; Eunbi KIM ; Hyebin LEE ; Na-young SHIN ; Yoonho NAM
Investigative Magnetic Resonance Imaging 2021;25(3):156-163
Recently, neuromelanin and nigrosome imaging techniques have been developed to evaluate the substantia nigra in Parkinson’s disease. Previous studies have shown potential benefits of quantitative analysis of neuromelanin and nigrosome images in the substantia nigra, although visual assessments have been performed to evaluate structures in most studies. In this study, we investigate the potential of using deep learning based automatic region segmentation techniques for quantitative analysis of the substantia nigra. The deep convolutional neural network was trained to automatically segment substantia nigra regions on 3D nigrosome and neuromelanin sensitive MR images obtained from 30 subjects. With a 5-fold cross-validation, the mean calculated dice similarity coefficient between manual and deep learning was 0.70 ± 0.11. Although calculated dice similarity coefficients were relatively low due to empirically drawn margins, selected slices were overlapped for more than two slices of all subjects. Our results demonstrate that deep convolutional neural network-based method could provide reliable localization of substantia nigra regions on neuromelanin and nigrosome sensitive MR images.
10.Tryptophanyl-tRNA Synthetase Sensitizes Hormone Receptor-Positive Breast Cancer to Docetaxel-Based Chemotherapy
Kyung-Min LEE ; Eun Hye HWANG ; Seong Eun KANG ; Cheng Hyun LEE ; Hyebin LEE ; Hyeon Jeong OH ; Kwangsoo KIM ; Jiwon KOH ; Han Suk RYU
Journal of Breast Cancer 2020;23(6):599-609
Purpose:
A relatively low response to chemotherapy has been reported for hormone receptor (HR)-positive breast cancer. In this study, we investigated the role of tryptophanyl-transfer RNA synthetase (WARS) in the chemotherapeutic response of HR-positive breast cancer.
Methods:
Pre-chemotherapeutic needle biopsy samples of 45 HR-positive breast cancer patients undergoing the same chemotherapeutic regimen were subjected to immunohistochemistry. To investigate the biological functions of WARS in HR-positive breast cancer, we conducted cell viability assay, flow cytometry analysis, caspase activity assay, Quantitative real-time polymerase chain reaction, and western blotting using WARS gene-modulated HR-positive breast cancer cells (T47D, ZR-75-1, and MCF7).
Results:
WARS overexpression in HR-positive breast cancer patients showed a significant correlation with favorable chemotherapy response. Downregulation of WARS increased cell viability following docetaxel treatment in tumor cell lines. On the other hand, WARS overexpression sensitized the therapeutic response to docetaxel. Additionally, downregulation of WARS caused a decrease in the number of apoptotic cell populations by docetaxel. Poly (ADP-ribose) polymerase cleavage and caspase 3/7 activity were increased in docetaxel-treated tumor cells with WARS overexpression.
Conclusion
Our results suggest that WARS might be a potential predictor for chemotherapy response in patients with HR-positive breast cancer as well as a novel molecular target to improve chemosensitivity.

Result Analysis
Print
Save
E-mail