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153 results on '"Ki, Yongkan"'

5. Analysis of risk factors for disease progression after salvage radiation therapy with androgen deprivation therapy in prostate cancer patients who have prostate-specific antigen persistence after radical prostatectomy

Author

Lee, Kyeonghyo, primary, Kim, Dongchan, additional, Nam, Jiho, additional, Park, Dahl, additional, Kim, Wontaek, additional, Joo, Jihyeon, additional, Jeon, Hosang, additional, Ki, Yongkan, additional, and Kim, Donghyun, additional

Published
2024
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6. Low albumin-to-alkaline phosphatase ratio is associated with inferior prognosis in patients with head and neck cancer underwent concurrent chemoradiation: A propensity score-matched analysis

Author

Kim, Donghyun, Ki, Yongkan, Kim, Wontaek, Park, Dahl, Joo, Jihyeon, Jeon, Hosang, and Nam, Jiho

Subjects
Cancer patients -- Prognosis, Patient compliance -- Analysis, Phosphatases -- Analysis, Cancer -- Care and treatment, Albumin -- Analysis, Head and neck cancer -- Prognosis -- Development and progression, Health
Abstract

Byline: Donghyun. Kim, Yongkan. Ki, Wontaek. Kim, Dahl. Park, Jihyeon. Joo, Hosang. Jeon, Jiho. Nam Background: Low albumin-to-alkaline phosphatase ratio (AAPR) is associated with tumor progression and poor survival outcome [...]

Published
2023

8. Effect of the Collimator Angle on Dosimetric Verification of the Volumetric Modulated Arc Therapy

Author

Kim, Yong Ho, Park, Ha Ryung, Kim, Won Taek, Kim, Dong Won, Ki, Yongkan, Lee, Juhye, Bae, Jinsuk, and Park, Dahl

Subjects
Physics - Medical Physics
Abstract

Collimator angle is usually rotated when planning volumetric modulated arc therapy (VMAT) due to the leakage of radiation between multi-leaf collimator (MLC) leaves. We studied the effect of the collimator angles on the results of dosimetric verification of the VMAT plans for head and neck patients. We studied VMAT plans for 10 head and neck patients. We made 2 sets of VMAT plans for each patient. Each set was composed of 10 plans with collimator angles of 0, 5, 10, 15, 20, 25, 30, 35, 40, 45 degrees. Plans in the first set were optimized individually and plans in the second set shared the 30 degree collimator angle optimization. Two sets of plans were verified using the 2-dimensional ion chamber array MatriXX (IBA Dosimetry, Germany). The comparison between the calculation and measurements were made by the $\gamma$-index analysis. The $\gamma$-index (2\%/2 mm) and (3\%/3 mm) passing rates had negative correlations with the collimator angle. Maximum difference between $\gamma$-index (3\%/3 mm) passing rates of different collimator angles for each patient ranged from 1.46\% to 5.60\% with an average of 3.67\%. There were significant differences (maximum 5.6\%) in the passing rates of different collimator angles. The results suggested that the accuracy of the delivered dose depends on the collimator angle. These findings are informative when choosing a collimator angle in VMAT plans., Comment: 10 pages, 5 figures

Published
2015

11. Changing trends in the management of ductal carcinoma in situ in Republic of Korea: a comprehensive analysis using Health Insurance Review and Assessment data [2009–2020]

Author

Joo, Ji Hyeon, primary, Kim, Wontaek, additional, Nam, Jiho, additional, Kim, Donghyun, additional, Kim, Hyun Yul, additional, Jung, Youn Joo, additional, Choo, Ki Seok, additional, Nam, Kyung Jin, additional, Nam, Su Bong, additional, Kim, Jae-Joon, additional, and Ki, Yongkan, additional

Published
2024
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21. Prognostic value of the maximum standardized uptake value for the locoregional control in early glottic cancer

Author

Kim, Donghyun, Ki, Yongkan, Joo, Jihyeon, Jeon, Hosang, Park, Dahl, Nam, Jiho, and Kim, Wontaek

Subjects
Radiotherapy, Oncology, Original Article, SUVmax, Radiology, Nuclear Medicine and imaging, Clinical Investigation, Laryngeal neoplasm
Abstract

Purpose: To evaluate the prognostic value of the pretreatment maximum standardized uptake value (SUVmax) for locoregional control (LRC) of early glottic cancer treated with primary radiotherapy.Materials and Methods: We retrospectively reviewed the medical records of 101 patients with T1-T2N0 glottic cancer treated with helical tomotherapy between 2013 and 2016. The clinical T-stages were T1 in 87 (86.1%) and T2 in 14 (13.9%) patients. The median total dose was 63 Gy (63–67.5 Gy) in 2.25 Gy per fraction. The survival outcomes were plotted using Kaplan-Meier curves. Receiver operating characteristic curves were used to assess the optimal SUVmax cut-off value for predicting locoregional recurrence.Results: The median follow-up period was 58 months (range, 11 to 90 months). The 5-year overall survival (OS) and locoregional recurrence-free survival rates were 96.8% and 85.4%, respectively. The median pretreatment SUVmax of the primary tumor for all 101 patients was 2.3 (range, 1.1 to 9.1). The best cut-off value for SUVmax for predicting LRC was 3.3, with a sensitivity of 78.6% and specificity of 73.6%. Univariate analysis showed that T-stage, overall treatment time (≥43 days), and high SUVmax (≥3.3) were significant predictors of LRC. Multivariate analysis showed that LRC was independently affected by a high SUVmax (≥3.3) (hazard ratio = 5.505, p = 0.020).Conclusion: High pretreatment SUVmax (≥3.3) is a negative prognostic factor for LRC in early glottic cancer patients treated with primary radiotherapy.

Published
2021

27. Influence of respiratory movement during post mastectomy radiotherapy on targets and heart for breast cancer.

Author

Jeon, Hosang, Ki, Yongkan, Kim, Dong Woon, Kim, Wontaek, Nam, Jiho, Kim, Donghyun, Park, Dahl, Park, Jongmoo, and Joo, Ji Hyeon

Subjects
*VOLUMETRIC-modulated arc therapy, *BREAST cancer, *MASTECTOMY, *RADIOTHERAPY, *MEDICAL dosimetry, *ABSOLUTE value, *MAMMAPLASTY
Abstract

Background/aim: This study aimed to compare the dosimetric consequences of respiratory movement in volumetric‐modulated arc therapy (VMAT) and three‐dimensional conformal radiation therapy (3D‐CRT) during postmastectomy radiation therapy, including internal mammary nodes (IMNs). Materials and methods: Respiratory motion was implemented to a phantom using a dynamic device. The plans were delivered during cranial‐caudal and ventral‐dorsal movement in 5‐mm (R05) and 10‐mm (R10) amplitudes. Results: At the IMN, the dose errors were –2.8% (R05) and –6.2% (R10) for 3D‐CRT and –4.9% (R05) and –8.5% (R10) for VMAT. The dose errors in chest wall were –.5% (R05) and –6.0% (R10) for 3D‐CRT and –1.9% (R05) and –5.3% (R10) for VMAT. The left anterior descending doses showed significantly small absolute values. The gamma pass rates of VMAT were higher than those of 3D‐CRT. Conclusions: The benefit of VMAT technique in dose distribution was maintained, except in occasional instances of large breathing motion. [ABSTRACT FROM AUTHOR]

Published
2023
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35. Risk factors for primary site necrosis after definitive concurrent chemoradiotherapy in head and neck cancer

Author

Kim, Donghyun, Ki, Yongkan, Kim, Wontaek, Park, Dahl, Joo, Jihyeon, Jeon, Hosang, Lee, Kyeonghyo, and Nam, Jiho

Abstract

Objective: To identify risk factors of primary site necrosis (PSN) after definitive concurrent chemoradiation therapy (CCRT) in patients with nonoral cavity head and neck cancer (HNC).Methods: We retrospectively reviewed the records of 256 patients treated with CCRT for HNC during 2010–2018. Patient-related (age, sex, history of smoking, hypertension, diabetes mellitus, serum hemoglobin and albumin), tumor-related (tumor site, American Joint Committee on Cancer stage), and treatment-related (induction chemotherapy, maximum point dose and mean dose of planning target volume [PTV] of primary site, absolute volumes of the PTV receiving >50–75 Gy [V50–V75]) variables were analyzed. Critical dosimetric parameters of PSN were identified using receiver operating characteristic (ROC) curve analysis. Univariate and multivariate Cox regression analyses were used to select the significant variables for PSN development.Results: After median follow-up of 44 months (range, 5–127), 7 patients (2.7%) developed PSN with a median time to event of 10 months (range, 3–12). V70⩾79.8 mL was the most critical dosimetric parameter for PSN (area under the ROC curve 0.873, sensitivity 0.857, specificity 0.747). In univariate analyses, pretreatment serum hemoglobin <11.0 g/dL and V70⩾79.8 mL were significantly associated with higher risk of PSN occurrence. V70⩾79.8 mL (hazard ratio 5.960, 95% confidence interval 1.289–27.548; p= 0.022) remained significant predictors of PSN in multivariate analyses.Conclusions: V70⩾79.8 mL is significantly related to the risk of developing PSN. These findings offer valuable clues for clinicians to minimize PSN incidence in HNC treated with curative CCRT.

Published
2023
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43. Who are the optimal candidates for partial breast irradiation?

Author

Joo, Ji Hyeon, Ki, Yongkan, Jeon, Hosang, Kim, Dong Woon, Jung, Jinhong, and Kim, Su Ssan

Subjects
*ACCELERATED partial breast irradiation, *IRRADIATION
Abstract

At the 2017 St. Gallen International Expert Consensus Conference on the Primary Therapy for Early Breast Cancer, the consensus panel recognized "partial breast irradiation as an option for women meeting the low‐risk criteria put forward by the American Society for Radiation Oncology/European Society for Radiotherapy and Oncology (ASTRO/ESTRO) guideline," although acknowledging that there was less evidence for this approach. Partial breast irradiation is defined as irradiation localized to the surgical resection cavity only as opposed to the entire breast. Accelerated partial breast irradiation (APBI) involves intensive treatment in a short time period. The methods vary, and three available APBI options are brachytherapy, external beam and intra‐operative irradiation. The long‐term follow‐up results from two large‐scale, well‐designed phase III randomized clinical trials have been released. However, further discussion of the optimal treatment candidates and delivery method is needed before the clinical application of APBI as a mainstream breast conservation treatment. [ABSTRACT FROM AUTHOR]

Published
2021
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44. Comparison of local recurrence after mastectomy for pure ductal carcinoma in situ with close or positive margins: A meta-analysis.

Author

Kim, Donghyun, Ki, Yongkan, Kim, Wontaek, Park, Dahl, Joo, Jihyeon, Jeon, Hosang, and Nam, Jiho

Subjects
*DUCTAL carcinoma, *MASTECTOMY, *CARCINOMA in situ, *BREAST cancer, *CONFIDENCE intervals, *RADIOTHERAPY
Abstract

Background: There is controversy regarding the relationship between margin status and risk of local recurrence (LR) in patients with Ductal carcinoma in situ(DCIS) treated by mastectomy. Purpose: We sought to assess the LR rates for patients with DCIS breast cancer treated by mastectomy with respect to the resection margin (RM) status. Materials and Methods: Systematic search of MEDLINE, EMBASE, and Cochrane library published was performed. Studies of pure DCIS breast cancer with treatment of mastectomy and studies that reported surgical RM and LR were included. Results:A total of 12 retrospective studies were included, encompassing 2902 patients with a mean follow-up of 86.4 months. Overall LR rates were 5.3% (27/508) for positive or close margins and 1.6% (37/2367) for negative margin, and most of the recurrences (93.7%) are invasive cancers. Patients with positive or close margins showed a 3.72-fold (95% confidence interval [CI] = 2.30–6.01,P < 0.01, I[2] = 11%) higher risk of LR than patients with negative margin. Patients with positive margin showed a 2.91-fold (95% CI = 1.14–7.41,P = 0.03, I[2] = 0%) higher risk of LR than patients with close margin. Postmastectomy radiation therapy (RT) was not associated with a decreased risk of LR (Risk ratio 0.50; 95% CI = 0.06–4.08,P= 0.52, I[2] = 0%) in patients with positive or close margins. Conclusions: The RM status after mastectomy has a great impact on LR. However, the recurrence rate was insufficient to warrant a recommendation for postmastectomy RT in patients with close or positive margins. [ABSTRACT FROM AUTHOR]

Published
2020
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45. Comparison of local recurrence after mastectomy for pure ductal carcinoma with close or positive margins: A meta-analysis.

Author

Kim, Donghyun, Ki, Yongkan, Kim, Wontaek, Park, Dahl, Joo, Jihyeon, Jeon, Hosang, and Nam, Jiho

Subjects
ADENOCARCINOMA, RESEARCH, META-analysis, CARCINOGENESIS, RESEARCH methodology, CANCER relapse, RETROSPECTIVE studies, EVALUATION research, MEDICAL cooperation, TREATMENT effectiveness, COMPARATIVE studies, MASTECTOMY, BREAST tumors
Abstract

Background: There is controversy regarding the relationship between margin status and risk of local recurrence (LR) in patients with Ductal carcinoma in situ(DCIS) treated by mastectomy.Purpose: We sought to assess the LR rates for patients with DCIS breast cancer treated by mastectomy with respect to the resection margin (RM) status.Materials and Methods: Systematic search of MEDLINE, EMBASE, and Cochrane library published was performed. Studies of pure DCIS breast cancer with treatment of mastectomy and studies that reported surgical RM and LR were included.Results: A total of 12 retrospective studies were included, encompassing 2902 patients with a mean follow-up of 86.4 months. Overall LR rates were 5.3% (27/508) for positive or close margins and 1.6% (37/2367) for negative margin, and most of the recurrences (93.7%) are invasive cancers. Patients with positive or close margins showed a 3.72-fold (95% confidence interval [CI] = 2.30-6.01,P < 0.01, I[2] = 11%) higher risk of LR than patients with negative margin. Patients with positive margin showed a 2.91-fold (95% CI = 1.14-7.41,P = 0.03, I[2] = 0%) higher risk of LR than patients with close margin. Postmastectomy radiation therapy (RT) was not associated with a decreased risk of LR (Risk ratio 0.50; 95% CI = 0.06-4.08,P= 0.52, I[2] = 0%) in patients with positive or close margins.Conclusions: The RM status after mastectomy has a great impact on LR. However, the recurrence rate was insufficient to warrant a recommendation for postmastectomy RT in patients with close or positive margins. [ABSTRACT FROM AUTHOR]

Published
2020
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49. Effect of Coenzyme Q10 on Radiation Nephropathy in Rats

Author

Ki, Yongkan, primary, Kim, Wontaek, additional, Kim, Yong Ho, additional, Kim, Donghyun, additional, Bae, Jin Sook, additional, Park, Dahl, additional, Jeon, Hosang, additional, Lee, Ju Hye, additional, Lee, Jayoung, additional, and Nam, Jiho, additional

Published
2017
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