1.Simulating the Effect of Junction Setup Error in Dual-Isocentric Volumetric Modulated Arc Therapy for Pelvic Radiotherapy with a Large Target
Hojeong LEE ; Dong Woon KIM ; Ji Hyeon JOO ; Yongkan KI ; Wontaek KIM ; Dahl PARK ; Jiho NAM ; Dong Hyeon KIM ; Hosang JEON
Progress in Medical Physics 2024;35(2):52-57
Purpose:
The use of two adjacent radiation beams to treat a lesion that is larger than the maximum field of a machine may lead to higher or lower dose distribution at the junction than expected. Therefore, evaluation of the junction dose is crucial for radiotherapy. Volumetric modulated arc therapy (VMAT) can effectively protect surrounding normal tissues by implementing a complex dose distribution; therefore, two adjacent VMAT fields can effectively treat large lesions. However, VMAT can lead to significant errors in the junction dose between fields if setup errors occur due to its highly complex dose distributions.
Methods:
In this study, setup errors of ±1, ±3, and ±5 mm were assumed during radiotherapy for treating large lesions in the lower abdomen, and their effects on the treatment dose distribution and target coverage were analyzed using gamma pass rate (GP) and homogeneity index (HI). All studies were performed using a computational simulation method based on our radiation treatment planning software.
Results:
Consequently, when the setup error was more than ±3 mm, most GP values using a 3%/3-mm criterion decreased by <90%. GP was independent of the direction of the field gap (FG), whereas HI values were relatively more affected by negative values for FG.
Conclusions
Therefore, the size and direction of setup errors should be carefully managed when performing dual-isocentric VMATs for large targets.
2.Simulating the Effect of Junction Setup Error in Dual-Isocentric Volumetric Modulated Arc Therapy for Pelvic Radiotherapy with a Large Target
Hojeong LEE ; Dong Woon KIM ; Ji Hyeon JOO ; Yongkan KI ; Wontaek KIM ; Dahl PARK ; Jiho NAM ; Dong Hyeon KIM ; Hosang JEON
Progress in Medical Physics 2024;35(2):52-57
Purpose:
The use of two adjacent radiation beams to treat a lesion that is larger than the maximum field of a machine may lead to higher or lower dose distribution at the junction than expected. Therefore, evaluation of the junction dose is crucial for radiotherapy. Volumetric modulated arc therapy (VMAT) can effectively protect surrounding normal tissues by implementing a complex dose distribution; therefore, two adjacent VMAT fields can effectively treat large lesions. However, VMAT can lead to significant errors in the junction dose between fields if setup errors occur due to its highly complex dose distributions.
Methods:
In this study, setup errors of ±1, ±3, and ±5 mm were assumed during radiotherapy for treating large lesions in the lower abdomen, and their effects on the treatment dose distribution and target coverage were analyzed using gamma pass rate (GP) and homogeneity index (HI). All studies were performed using a computational simulation method based on our radiation treatment planning software.
Results:
Consequently, when the setup error was more than ±3 mm, most GP values using a 3%/3-mm criterion decreased by <90%. GP was independent of the direction of the field gap (FG), whereas HI values were relatively more affected by negative values for FG.
Conclusions
Therefore, the size and direction of setup errors should be carefully managed when performing dual-isocentric VMATs for large targets.
3.Simulating the Effect of Junction Setup Error in Dual-Isocentric Volumetric Modulated Arc Therapy for Pelvic Radiotherapy with a Large Target
Hojeong LEE ; Dong Woon KIM ; Ji Hyeon JOO ; Yongkan KI ; Wontaek KIM ; Dahl PARK ; Jiho NAM ; Dong Hyeon KIM ; Hosang JEON
Progress in Medical Physics 2024;35(2):52-57
Purpose:
The use of two adjacent radiation beams to treat a lesion that is larger than the maximum field of a machine may lead to higher or lower dose distribution at the junction than expected. Therefore, evaluation of the junction dose is crucial for radiotherapy. Volumetric modulated arc therapy (VMAT) can effectively protect surrounding normal tissues by implementing a complex dose distribution; therefore, two adjacent VMAT fields can effectively treat large lesions. However, VMAT can lead to significant errors in the junction dose between fields if setup errors occur due to its highly complex dose distributions.
Methods:
In this study, setup errors of ±1, ±3, and ±5 mm were assumed during radiotherapy for treating large lesions in the lower abdomen, and their effects on the treatment dose distribution and target coverage were analyzed using gamma pass rate (GP) and homogeneity index (HI). All studies were performed using a computational simulation method based on our radiation treatment planning software.
Results:
Consequently, when the setup error was more than ±3 mm, most GP values using a 3%/3-mm criterion decreased by <90%. GP was independent of the direction of the field gap (FG), whereas HI values were relatively more affected by negative values for FG.
Conclusions
Therefore, the size and direction of setup errors should be carefully managed when performing dual-isocentric VMATs for large targets.
4.Simulating the Effect of Junction Setup Error in Dual-Isocentric Volumetric Modulated Arc Therapy for Pelvic Radiotherapy with a Large Target
Hojeong LEE ; Dong Woon KIM ; Ji Hyeon JOO ; Yongkan KI ; Wontaek KIM ; Dahl PARK ; Jiho NAM ; Dong Hyeon KIM ; Hosang JEON
Progress in Medical Physics 2024;35(2):52-57
Purpose:
The use of two adjacent radiation beams to treat a lesion that is larger than the maximum field of a machine may lead to higher or lower dose distribution at the junction than expected. Therefore, evaluation of the junction dose is crucial for radiotherapy. Volumetric modulated arc therapy (VMAT) can effectively protect surrounding normal tissues by implementing a complex dose distribution; therefore, two adjacent VMAT fields can effectively treat large lesions. However, VMAT can lead to significant errors in the junction dose between fields if setup errors occur due to its highly complex dose distributions.
Methods:
In this study, setup errors of ±1, ±3, and ±5 mm were assumed during radiotherapy for treating large lesions in the lower abdomen, and their effects on the treatment dose distribution and target coverage were analyzed using gamma pass rate (GP) and homogeneity index (HI). All studies were performed using a computational simulation method based on our radiation treatment planning software.
Results:
Consequently, when the setup error was more than ±3 mm, most GP values using a 3%/3-mm criterion decreased by <90%. GP was independent of the direction of the field gap (FG), whereas HI values were relatively more affected by negative values for FG.
Conclusions
Therefore, the size and direction of setup errors should be carefully managed when performing dual-isocentric VMATs for large targets.
5.Simulating the Effect of Junction Setup Error in Dual-Isocentric Volumetric Modulated Arc Therapy for Pelvic Radiotherapy with a Large Target
Hojeong LEE ; Dong Woon KIM ; Ji Hyeon JOO ; Yongkan KI ; Wontaek KIM ; Dahl PARK ; Jiho NAM ; Dong Hyeon KIM ; Hosang JEON
Progress in Medical Physics 2024;35(2):52-57
Purpose:
The use of two adjacent radiation beams to treat a lesion that is larger than the maximum field of a machine may lead to higher or lower dose distribution at the junction than expected. Therefore, evaluation of the junction dose is crucial for radiotherapy. Volumetric modulated arc therapy (VMAT) can effectively protect surrounding normal tissues by implementing a complex dose distribution; therefore, two adjacent VMAT fields can effectively treat large lesions. However, VMAT can lead to significant errors in the junction dose between fields if setup errors occur due to its highly complex dose distributions.
Methods:
In this study, setup errors of ±1, ±3, and ±5 mm were assumed during radiotherapy for treating large lesions in the lower abdomen, and their effects on the treatment dose distribution and target coverage were analyzed using gamma pass rate (GP) and homogeneity index (HI). All studies were performed using a computational simulation method based on our radiation treatment planning software.
Results:
Consequently, when the setup error was more than ±3 mm, most GP values using a 3%/3-mm criterion decreased by <90%. GP was independent of the direction of the field gap (FG), whereas HI values were relatively more affected by negative values for FG.
Conclusions
Therefore, the size and direction of setup errors should be carefully managed when performing dual-isocentric VMATs for large targets.
6.The Usefulness of 18 F-FDG PET to Differentiate Subtypes of Dementia:The Systematic Review and Meta-Analysis
Seunghee NA ; Dong Woo KANG ; Geon Ha KIM ; Ko Woon KIM ; Yeshin KIM ; Hee-Jin KIM ; Kee Hyung PARK ; Young Ho PARK ; Gihwan BYEON ; Jeewon SUH ; Joon Hyun SHIN ; YongSoo SHIM ; YoungSoon YANG ; Yoo Hyun UM ; Seong-il OH ; Sheng-Min WANG ; Bora YOON ; Hai-Jeon YOON ; Sun Min LEE ; Juyoun LEE ; Jin San LEE ; Hak Young RHEE ; Jae-Sung LIM ; Young Hee JUNG ; Juhee CHIN ; Yun Jeong HONG ; Hyemin JANG ; Hongyoon CHOI ; Miyoung CHOI ; Jae-Won JANG ; On behalf of Korean Dementia Association
Dementia and Neurocognitive Disorders 2024;23(1):54-66
Background:
and Purpose: Dementia subtypes, including Alzheimer’s dementia (AD), dementia with Lewy bodies (DLB), and frontotemporal dementia (FTD), pose diagnostic challenges. This review examines the effectiveness of 18 F-Fluorodeoxyglucose Positron Emission Tomography ( 18 F-FDG PET) in differentiating these subtypes for precise treatment and management.
Methods:
A systematic review following Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines was conducted using databases like PubMed and Embase to identify studies on the diagnostic utility of 18 F-FDG PET in dementia. The search included studies up to November 16, 2022, focusing on peer-reviewed journals and applying the goldstandard clinical diagnosis for dementia subtypes.
Results:
From 12,815 articles, 14 were selected for final analysis. For AD versus FTD, the sensitivity was 0.96 (95% confidence interval [CI], 0.88–0.98) and specificity was 0.84 (95% CI, 0.70–0.92). In the case of AD versus DLB, 18F-FDG PET showed a sensitivity of 0.93 (95% CI 0.88-0.98) and specificity of 0.92 (95% CI, 0.70–0.92). Lastly, when differentiating AD from non-AD dementias, the sensitivity was 0.86 (95% CI, 0.80–0.91) and the specificity was 0.88 (95% CI, 0.80–0.91). The studies mostly used case-control designs with visual and quantitative assessments.
Conclusions
18 F-FDG PET exhibits high sensitivity and specificity in differentiating dementia subtypes, particularly AD, FTD, and DLB. This method, while not a standalone diagnostic tool, significantly enhances diagnostic accuracy in uncertain cases, complementing clinical assessments and structural imaging.
7.Lipid-Lowering Efficacy of Combination Therapy With ModerateIntensity Statin and Ezetimibe Versus High-Intensity Statin Monotherapy:A Randomized, Open-Label, NonInferiority Trial From Korea
Hyejung CHOI ; Si-Hyuck KANG ; Sang-Woo JEONG ; Chang-Hwan YOON ; Tae-Jin YOUN ; Woo Hyuk SONG ; Dong Woon JEON ; Sang Wook LIM ; Jun-Hee LEE ; Seong-Wook CHO ; In-Ho CHAE ; Cheol-Ho KIM
Journal of Lipid and Atherosclerosis 2023;12(3):277-289
Objective:
This phase IV, multicenter, randomized controlled, open-label, and parallel clinical trial aimed to compare the efficacy and safety of ezetimibe and moderate intensity rosuvastatin combination therapy to that of high intensity rosuvastatin monotherapy in patients with atherosclerotic cardiovascular disease (ASCVD).
Methods:
This study enrolled patients with ASCVD and after a four-week screening period, patients were randomly assigned to receive either rosuvastatin and ezetimibe (RE 10/10 group) or high-intensity rosuvastatin (R20 group) only in a 1:1 ratio. The primary outcome was the difference in the percent change in the mean low-density lipoprotein cholesterol (LDL-C) level from baseline to 12 weeks between two groups after treatment.
Results:
The study found that after 12 and 24 weeks of treatment, the RE10/10 group had a greater reduction in LDL-C level compared to the R20 group (−22.9±2.6% vs. −15.6 ± 2.5% [p=0.041] and −24.2±2.5% vs. −12.9±2.4% [p=0.001] at 12 and 24 weeks, respectively). Moreover, a greater number of patients achieved the target LDL-C level of ≤70 mg/dL after the treatment period in the combination group (74.6% vs. 59.9% [p=0.012] and 76.2% vs. 50.8% [p<0.001] at 12 and 24 weeks, respectively). Importantly, there were no significant differences in the occurrence of overall adverse events and adverse drug reactions between two groups.
Conclusion
Moderate-intensity rosuvastatin and ezetimibe combination therapy had better efficacy in lowering LDL-C levels without increasing adverse effects in patients with ASCVD than high-intensity rosuvastatin monotherapy.
8.Clinical safety and effectiveness of the Genoss drug-eluting stent in real-world clinical practice
Young Jin YOUN ; Jun-Won LEE ; Sung Gyun AHN ; Seung-Hwan LEE ; Junghan YOON ; Jae Hyoung PARK ; Sang-Yong YOO ; Woong Chol KANG ; Nam Ho LEE ; Ki Hwan KWON ; Joon Hyung DOH ; Sang-Wook LIM ; Yang Soo JANG ; Dong Woon JEON ; Jung Ho HEO ; Woong Gil CHOI ; Sungsoo CHO ; Bong-Ki LEE ; Hyonju JEONG ; Bum-Kee HONG ; Hyun-Hee CHOI
The Korean Journal of Internal Medicine 2023;38(5):683-691
Background/Aims:
The Genoss DES™ is a novel, biodegradable, polymer-coated, sirolimus-eluting stent with a cobalt- chromium stent platform and thin strut. Although the safety and effectiveness of this stent have been previously investigated, real-world clinical outcomes data are lacking. Therefore, the aim of this prospective, multicenter trial was to evaluate the clinical safety and effectiveness of the Genoss DES™ in all-comer patients undergoing percutaneous coronary intervention.
Methods:
The Genoss DES registry is a prospective, single-arm, observational trial for evaluation of clinical outcomes after Genoss DES™ implantation in all-comer patients undergoing percutaneous coronary intervention from 17 sites in South Korea. The primary endpoint was a device-oriented composite outcome of cardiac death, target vessel-related myocardial infarction (MI), and clinically driven target lesion revascularization (TLR) at 12 months.
Results:
A total of 1,999 patients (66.4 ± 11.1 years of age; 72.8% male) were analyzed. At baseline, 62.8% and 36.7% of patients had hypertension and diabetes, respectively. The implanted stent number, diameter, and length per patient were 1.5 ± 0.8, 3.1 ± 0.5 mm, and 37.0 ± 25.0 mm, respectively. The primary endpoint occurred in 1.8% patients, with a cardiac death rate of 1.1%, target vessel-related MI rate of 0.2%, and clinically driven TLR rate of 0.8%.
Conclusions
In this real-world registry, the Genoss DES™ demonstrated excellent safety and effectiveness at 12 months among all-comer patients undergoing percutaneous coronary intervention. These findings suggest that the Genoss DES™ may be a viable treatment option for patients with coronary artery disease.
9.Ticagrelor Monotherapy After 3-Month Dual Antiplatelet Therapy in Acute Coronary Syndrome by High Bleeding Risk: The Subanalysis From the TICO Trial
Yong-Joon LEE ; Yongsung SUH ; Jung-Sun KIM ; Yun-Hyeong CHO ; Kyeong Ho YUN ; Yong Hoon KIM ; Jae Young CHO ; Ae-Young HER ; Sungsoo CHO ; Dong Woon JEON ; Sang-Yong YOO ; Deok-Kyu CHO ; Bum-Kee HONG ; Hyuckmoon KWON ; Sung-Jin HONG ; Chul-Min AHN ; Dong-Ho SHIN ; Chung-Mo NAM ; Byeong-Keuk KIM ; Young-Guk KO ; Donghoon CHOI ; Myeong-Ki HONG ; Yangsoo JANG ; For the TICO investigators
Korean Circulation Journal 2022;52(4):324-337
Background and Objectives:
Identifying patients with high bleeding risk (HBR) is important when making decisions for antiplatelet therapy strategy. This study evaluated the impact of ticagrelor monotherapy after 3-month dual antiplatelet therapy (DAPT) according to HBR in acute coronary syndrome (ACS) patients treated with drug eluting stents (DESs).
Methods:
In this post-hoc analysis of the TICO trial, HBR was defined by 2 approaches: meeting Academic Research Consortium for HBR (ARC-HBR) criteria or Predicting Bleeding Complications in Patients Undergoing Stent Implantation and Subsequent DAPT (PRECISEDAPT) score ≥25. The primary outcome was a 3–12 months net adverse clinical event (composite of major bleeding and adverse cardiac and cerebrovascular events).
Results:
Of the 2,980 patients without adverse events during the first 3 months after DES implantation, 453 (15.2%) were HBR by ARC-HBR criteria and 504 (16.9%) were HBR by PRECISE-DAPT score. The primary outcome rate was higher in HBR versus non-HBR patients (by ARC-HBR criteria: hazard ratio [HR], 2.87; 95% confidence interval [CI], 1.76– 4.69; p<0.001; by PRECISE-DAPT score: HR, 3.09; 95% CI, 1.92–4.98; p<0.001). Ticagrelor monotherapy after 3-month DAPT was associated with lower primary outcome rate than ticagrelor-based 12-month DAPT regardless of HBR by ARC-HBR criteria, with similar magnitudes of therapy effect for HBR and non-HBR patients (p-interaction=0.400). Results were consistent by PRECISE-DAPT score (p-interaction=0.178).
Conclusions
In ACS patients treated with DESs, ticagrelor monotherapy after 3-month DAPT was associated with lower rate of adverse clinical outcomes regardless of HBR, with similar magnitudes of therapy effect between HBR and non-HBR.Trial Registration: ClinicalTrials.gov Identifier: NCT02494895
10.Prasugrel-based De-Escalation of Dual Antiplatelet Therapy After Percutaneous Coronary Intervention in Patients With STEMI
You-Jeong KI ; Bong Ki LEE ; Kyung Woo PARK ; Jang-Whan BAE ; Doyeon HWANG ; Jeehoon KANG ; Jung-Kyu HAN ; Han-Mo YANG ; Hyun-Jae KANG ; Bon-Kwon KOO ; Dong-Bin KIM ; In-Ho CHAE ; Keon-Woong MOON ; Hyun Woong PARK ; Ki-Bum WON ; Dong Woon JEON ; Kyoo-Rok HAN ; Si Wan CHOI ; Jae Kean RYU ; Myung Ho JEONG ; Kwang Soo CHA ; Hyo-Soo KIM ; On behalf of the HOST-RP-ACS investigators
Korean Circulation Journal 2022;52(4):304-319
Background and Objectives:
De-escalation of dual-antiplatelet therapy through dose reduction of prasugrel improved net adverse clinical events (NACEs) after acute coronary syndrome (ACS), mainly through the reduction of bleeding without an increase in ischemic outcomes. Whether the benefits of de-escalation are sustained in highly thrombotic conditions such as ST-elevation myocardial infarction (STEMI) is unknown. We aimed to assess the efficacy and safety of de-escalation therapy in patients with STEMI or non-STsegment elevation ACS (NSTE-ACS).
Methods:
This is a pre-specified subgroup analysis of the HOST-REDUCE-POLYTECH-ACS trial. ACS patients were randomized to prasugrel de-escalation (5 mg daily) or conventional dose (10 mg daily) at 1-month post-percutaneous coronary intervention. The primary endpoint was a NACE, defined as a composite of all-cause death, non-fatal myocardial infarction, stent thrombosis, clinically driven revascularization, stroke, and bleeding events of grade ≥2 Bleeding Academic Research Consortium (BARC) criteria at 1 year.
Results:
Among 2,338 patients included in the randomization, 326 patients were diagnosed with STEMI. In patients with NSTE-ACS, the risk of the primary endpoint was significantly reduced with de-escalation (hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.48– 0.89; p=0.006 for de-escalation vs. conventional), mainly driven by a reduced bleeding. However, in those with STEMI, there was no difference in the occurrence of the primary outcome (HR, 1.04; 95% CI, 0.48–2.26; p=0.915; p for interaction=0.271).
Conclusions
Prasugrel dose de-escalation reduced the rate of NACE and bleeding, without increasing the rate of ischemic events in NSTE-ACS patients but not in STEMI patients.

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