1.Study Protocol of Expanded Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro-EXP)
Jae Hoon MOON ; Eun Kyung LEE ; Wonjae CHA ; Young Jun CHAI ; Sun Wook CHO ; June Young CHOI ; Sung Yong CHOI ; A Jung CHU ; Eun-Jae CHUNG ; Yul HWANGBO ; Woo-Jin JEONG ; Yuh-Seog JUNG ; Kyungsik KIM ; Min Joo KIM ; Su-jin KIM ; Woochul KIM ; Yoo Hyung KIM ; Chang Yoon LEE ; Ji Ye LEE ; Kyu Eun LEE ; Young Ki LEE ; Hunjong LIM ; Do Joon PARK ; Sue K. PARK ; Chang Hwan RYU ; Junsun RYU ; Jungirl SEOK ; Young Shin SONG ; Ka Hee YI ; Hyeong Won YU ; Eleanor WHITE ; Katerina MASTROCOSTAS ; Roderick J. CLIFTON-BLIGH ; Anthony GLOVER ; Matti L. GILD ; Ji-hoon KIM ; Young Joo PARK
Endocrinology and Metabolism 2025;40(2):236-246
Background:
Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making.
Methods:
This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes.
Conclusion
This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.
2.Study Protocol of Expanded Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro-EXP)
Jae Hoon MOON ; Eun Kyung LEE ; Wonjae CHA ; Young Jun CHAI ; Sun Wook CHO ; June Young CHOI ; Sung Yong CHOI ; A Jung CHU ; Eun-Jae CHUNG ; Yul HWANGBO ; Woo-Jin JEONG ; Yuh-Seog JUNG ; Kyungsik KIM ; Min Joo KIM ; Su-jin KIM ; Woochul KIM ; Yoo Hyung KIM ; Chang Yoon LEE ; Ji Ye LEE ; Kyu Eun LEE ; Young Ki LEE ; Hunjong LIM ; Do Joon PARK ; Sue K. PARK ; Chang Hwan RYU ; Junsun RYU ; Jungirl SEOK ; Young Shin SONG ; Ka Hee YI ; Hyeong Won YU ; Eleanor WHITE ; Katerina MASTROCOSTAS ; Roderick J. CLIFTON-BLIGH ; Anthony GLOVER ; Matti L. GILD ; Ji-hoon KIM ; Young Joo PARK
Endocrinology and Metabolism 2025;40(2):236-246
Background:
Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making.
Methods:
This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes.
Conclusion
This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.
3.Study Protocol of Expanded Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro-EXP)
Jae Hoon MOON ; Eun Kyung LEE ; Wonjae CHA ; Young Jun CHAI ; Sun Wook CHO ; June Young CHOI ; Sung Yong CHOI ; A Jung CHU ; Eun-Jae CHUNG ; Yul HWANGBO ; Woo-Jin JEONG ; Yuh-Seog JUNG ; Kyungsik KIM ; Min Joo KIM ; Su-jin KIM ; Woochul KIM ; Yoo Hyung KIM ; Chang Yoon LEE ; Ji Ye LEE ; Kyu Eun LEE ; Young Ki LEE ; Hunjong LIM ; Do Joon PARK ; Sue K. PARK ; Chang Hwan RYU ; Junsun RYU ; Jungirl SEOK ; Young Shin SONG ; Ka Hee YI ; Hyeong Won YU ; Eleanor WHITE ; Katerina MASTROCOSTAS ; Roderick J. CLIFTON-BLIGH ; Anthony GLOVER ; Matti L. GILD ; Ji-hoon KIM ; Young Joo PARK
Endocrinology and Metabolism 2025;40(2):236-246
Background:
Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making.
Methods:
This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes.
Conclusion
This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.
4.Study Protocol of Expanded Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro-EXP)
Jae Hoon MOON ; Eun Kyung LEE ; Wonjae CHA ; Young Jun CHAI ; Sun Wook CHO ; June Young CHOI ; Sung Yong CHOI ; A Jung CHU ; Eun-Jae CHUNG ; Yul HWANGBO ; Woo-Jin JEONG ; Yuh-Seog JUNG ; Kyungsik KIM ; Min Joo KIM ; Su-jin KIM ; Woochul KIM ; Yoo Hyung KIM ; Chang Yoon LEE ; Ji Ye LEE ; Kyu Eun LEE ; Young Ki LEE ; Hunjong LIM ; Do Joon PARK ; Sue K. PARK ; Chang Hwan RYU ; Junsun RYU ; Jungirl SEOK ; Young Shin SONG ; Ka Hee YI ; Hyeong Won YU ; Eleanor WHITE ; Katerina MASTROCOSTAS ; Roderick J. CLIFTON-BLIGH ; Anthony GLOVER ; Matti L. GILD ; Ji-hoon KIM ; Young Joo PARK
Endocrinology and Metabolism 2025;40(2):236-246
Background:
Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making.
Methods:
This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes.
Conclusion
This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.
5.Evaluation of Radioactivity in Therapeutic Radiopharmaceutical Waste
Jung Ju JO ; Su Hyoung LEE ; Beom Hoon KI ; Ho Jin RYU ; Tae Hwan KIM ; Gi Sub KIM ; Sang Kyu LEE ; Dong Wook KIM ; Kum Bae KIM ; Sangrok KIM ; Sang Hyoun CHOI
Progress in Medical Physics 2024;35(4):163-171
Purpose:
This study aims to systematically analyze the radioactive waste generated from treatments using radioactive Iodine-131 (I-131), Lutetium-177 (Lu-177), and Actinium-225 (Ac-225) to facilitate safe waste management practices.
Methods:
I-131 is primarily used in thyroid cancer treatment, while Lu-177 and Ac-225 are used to treat prostate cancer. Radioactive waste generated after these treatments was collected from patients at the Korea Cancer Center Hospital and categorized into clothing, slippers, syringes, and other items. The radioactivity concentration of each item was measured using a calibrated highpurity germanium detector. Using measurements, the self-disposal date of each waste item was calculated according to the permissible disposal levels defined by the Nuclear Safety and Security Commission (NSSC) under domestic nuclear safety regulations.
Results:
For the I-131 radioactive waste, clothing, towels, and tableware exhibited high radioactivity concentrations, with most items exceeding the permissible self-disposal levels.Conversely, the type and quantity of waste generated from Lu-177 and Ac-225 that were intravenously injected were relatively minimal, with certain items below the self-disposal thresholds, enabling immediate disposal. For Ac-225, no permissible self-disposal concentration is specified by the NSSC, unlike other therapeutic nuclides. Hence, additional studies are required to establish clear guidelines.
Conclusions
These findings provide valuable data for optimizing radioactive waste management, potentially reducing disposal time and costs, minimizing radiation exposure, and enhancing hospital safety practices.
6.Evaluation of Radioactivity in Therapeutic Radiopharmaceutical Waste
Jung Ju JO ; Su Hyoung LEE ; Beom Hoon KI ; Ho Jin RYU ; Tae Hwan KIM ; Gi Sub KIM ; Sang Kyu LEE ; Dong Wook KIM ; Kum Bae KIM ; Sangrok KIM ; Sang Hyoun CHOI
Progress in Medical Physics 2024;35(4):163-171
Purpose:
This study aims to systematically analyze the radioactive waste generated from treatments using radioactive Iodine-131 (I-131), Lutetium-177 (Lu-177), and Actinium-225 (Ac-225) to facilitate safe waste management practices.
Methods:
I-131 is primarily used in thyroid cancer treatment, while Lu-177 and Ac-225 are used to treat prostate cancer. Radioactive waste generated after these treatments was collected from patients at the Korea Cancer Center Hospital and categorized into clothing, slippers, syringes, and other items. The radioactivity concentration of each item was measured using a calibrated highpurity germanium detector. Using measurements, the self-disposal date of each waste item was calculated according to the permissible disposal levels defined by the Nuclear Safety and Security Commission (NSSC) under domestic nuclear safety regulations.
Results:
For the I-131 radioactive waste, clothing, towels, and tableware exhibited high radioactivity concentrations, with most items exceeding the permissible self-disposal levels.Conversely, the type and quantity of waste generated from Lu-177 and Ac-225 that were intravenously injected were relatively minimal, with certain items below the self-disposal thresholds, enabling immediate disposal. For Ac-225, no permissible self-disposal concentration is specified by the NSSC, unlike other therapeutic nuclides. Hence, additional studies are required to establish clear guidelines.
Conclusions
These findings provide valuable data for optimizing radioactive waste management, potentially reducing disposal time and costs, minimizing radiation exposure, and enhancing hospital safety practices.
7.Evaluation of Radioactivity in Therapeutic Radiopharmaceutical Waste
Jung Ju JO ; Su Hyoung LEE ; Beom Hoon KI ; Ho Jin RYU ; Tae Hwan KIM ; Gi Sub KIM ; Sang Kyu LEE ; Dong Wook KIM ; Kum Bae KIM ; Sangrok KIM ; Sang Hyoun CHOI
Progress in Medical Physics 2024;35(4):163-171
Purpose:
This study aims to systematically analyze the radioactive waste generated from treatments using radioactive Iodine-131 (I-131), Lutetium-177 (Lu-177), and Actinium-225 (Ac-225) to facilitate safe waste management practices.
Methods:
I-131 is primarily used in thyroid cancer treatment, while Lu-177 and Ac-225 are used to treat prostate cancer. Radioactive waste generated after these treatments was collected from patients at the Korea Cancer Center Hospital and categorized into clothing, slippers, syringes, and other items. The radioactivity concentration of each item was measured using a calibrated highpurity germanium detector. Using measurements, the self-disposal date of each waste item was calculated according to the permissible disposal levels defined by the Nuclear Safety and Security Commission (NSSC) under domestic nuclear safety regulations.
Results:
For the I-131 radioactive waste, clothing, towels, and tableware exhibited high radioactivity concentrations, with most items exceeding the permissible self-disposal levels.Conversely, the type and quantity of waste generated from Lu-177 and Ac-225 that were intravenously injected were relatively minimal, with certain items below the self-disposal thresholds, enabling immediate disposal. For Ac-225, no permissible self-disposal concentration is specified by the NSSC, unlike other therapeutic nuclides. Hence, additional studies are required to establish clear guidelines.
Conclusions
These findings provide valuable data for optimizing radioactive waste management, potentially reducing disposal time and costs, minimizing radiation exposure, and enhancing hospital safety practices.
8.The Accuracy of Implant Placement According to the Height of the Surgical Guide Hole
Kyu Won PARK ; Jihun CHA ; Seunggon JUNG ; Min‑Suk KOOK ; Hong-Ju PARK ; Hee-Kyun OH ; Jaeyoung RYU
Journal of Korean Dental Science 2024;17(4):201-209
Purpose:
This study investigated the impact of the guide hole height on the accuracy of implant placement using CAD/ CAM-fabricated surgical guides in resin models. The hypothesis is that decreasing the height of the guide hole reduces placement accuracy.
Materials and Methods:
Ten identical partially edentulous maxillary models were each fitted with surgical guides featuring guide hole heights of 1 mm, 3 mm, and/or 5 mm. Using a surgical guide and drill kit, implants were placed in six predetermined sites per model. Placement accuracy was evaluated by comparing the actual implant positions with the planned positions using digital scanning and computer software analysis. Statistical analyses were performed using ANOVA and Kruskal-Wallis tests to determine the significance of deviations at both the coronal and apical positions.
Results:
The average deviations were 0.75±0.33 mm at the coronal position and 1.10±0.51 mm at the apical position. Placement accuracy didnot differ with different guide hole heights. Additionally, errors were consistent regardless of the guide hole height and were not influenced by the type of support or the implant placement site.
Conclusion
In this rotro study, varying the height of the guide hole did not significantly affect the accuracy of implant placement. The results suggest that guide hole height within the tested range does not have a substantial impact on placement errors. Our findings indicate that factors other than the guide holeheight may play a more critical role in implant placement accuracy.
9.The Accuracy of Implant Placement According to the Height of the Surgical Guide Hole
Kyu Won PARK ; Jihun CHA ; Seunggon JUNG ; Min‑Suk KOOK ; Hong-Ju PARK ; Hee-Kyun OH ; Jaeyoung RYU
Journal of Korean Dental Science 2024;17(4):201-209
Purpose:
This study investigated the impact of the guide hole height on the accuracy of implant placement using CAD/ CAM-fabricated surgical guides in resin models. The hypothesis is that decreasing the height of the guide hole reduces placement accuracy.
Materials and Methods:
Ten identical partially edentulous maxillary models were each fitted with surgical guides featuring guide hole heights of 1 mm, 3 mm, and/or 5 mm. Using a surgical guide and drill kit, implants were placed in six predetermined sites per model. Placement accuracy was evaluated by comparing the actual implant positions with the planned positions using digital scanning and computer software analysis. Statistical analyses were performed using ANOVA and Kruskal-Wallis tests to determine the significance of deviations at both the coronal and apical positions.
Results:
The average deviations were 0.75±0.33 mm at the coronal position and 1.10±0.51 mm at the apical position. Placement accuracy didnot differ with different guide hole heights. Additionally, errors were consistent regardless of the guide hole height and were not influenced by the type of support or the implant placement site.
Conclusion
In this rotro study, varying the height of the guide hole did not significantly affect the accuracy of implant placement. The results suggest that guide hole height within the tested range does not have a substantial impact on placement errors. Our findings indicate that factors other than the guide holeheight may play a more critical role in implant placement accuracy.
10.The Accuracy of Implant Placement According to the Height of the Surgical Guide Hole
Kyu Won PARK ; Jihun CHA ; Seunggon JUNG ; Min‑Suk KOOK ; Hong-Ju PARK ; Hee-Kyun OH ; Jaeyoung RYU
Journal of Korean Dental Science 2024;17(4):201-209
Purpose:
This study investigated the impact of the guide hole height on the accuracy of implant placement using CAD/ CAM-fabricated surgical guides in resin models. The hypothesis is that decreasing the height of the guide hole reduces placement accuracy.
Materials and Methods:
Ten identical partially edentulous maxillary models were each fitted with surgical guides featuring guide hole heights of 1 mm, 3 mm, and/or 5 mm. Using a surgical guide and drill kit, implants were placed in six predetermined sites per model. Placement accuracy was evaluated by comparing the actual implant positions with the planned positions using digital scanning and computer software analysis. Statistical analyses were performed using ANOVA and Kruskal-Wallis tests to determine the significance of deviations at both the coronal and apical positions.
Results:
The average deviations were 0.75±0.33 mm at the coronal position and 1.10±0.51 mm at the apical position. Placement accuracy didnot differ with different guide hole heights. Additionally, errors were consistent regardless of the guide hole height and were not influenced by the type of support or the implant placement site.
Conclusion
In this rotro study, varying the height of the guide hole did not significantly affect the accuracy of implant placement. The results suggest that guide hole height within the tested range does not have a substantial impact on placement errors. Our findings indicate that factors other than the guide holeheight may play a more critical role in implant placement accuracy.

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