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Featured researches published by Mee Sun Yoon.


International Journal of Radiation Oncology Biology Physics | 2012

Metabolic Response of Lymph Nodes Immediately After RT Is Related With Survival Outcome of Patients With Pelvic Node-Positive Cervical Cancer Using Consecutive [18F]fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

Mee Sun Yoon; Sung-Ja Ahn; Byung-Sik Nah; Woong-Ki Chung; Ho-Chun Song; Su Woong Yoo; Ju-Young Song; Jae-Uk Jeong; Taek-Keun Nam

PURPOSE To evaluate the metabolic response of uterine cervix and pelvic lymph nodes (LNs) using consecutive 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT) immediately after RT and to correlate survival outcome with the metabolic response. METHODS AND MATERIALS We retrospectively reviewed 48 patients with cervical cancer who had positive pelvic LNs by preradiation therapy (pre-RT) PET/CT. All patients underwent PET/CT scans immediately after RT (inter-RT PET/CT) after median 63 Gy to the gross LNs. The metabolic response of the LNs was assessed quantitatively and semiquantitatively by measurement of the maximal standardized uptake value (SUVmax). RESULTS Classifying the metabolic response of all nodal lesions, 37 patients (77%) had LNs with complete metabolic response on the inter-RT PET/CT (LNCMRi), and 11 patients had a non-LNCMRi, including 4 patients with progressive metabolic disease. The overall 3-year survival rates were 83% for the patients with LNCMRi and 73% for the non-LNCMRi group (P=.038). The disease-free survival for patients with LNCMRi were significantly better than that for the non-LNCMRi group (71% vs 18%, respectively, P<.001). The 3-year distant metastasis-free survival rates were 79% for the patients with LNCMRi and 27% for the non-LNCMRi group (P<.001). There were no statistically significant differences in overall survival (76% vs 86%, respectively, P=.954) and disease-free survival rates (58% vs 61%, respectively, P=.818) between the CMR of primary cervical tumor and the non-CMR groups. CONCLUSIONS The results showed a significant correlation between survival outcome and the interim metabolic response of pelvic LNs. CMR of nodal lesion on inter-RT PET/CT had excellent overall survival, disease-free survival and distant metastasis-free survival rates. This suggested that PET/CT immediately after RT can be a useful tool for the evaluation of the interim response of the LNs and identify a subset of patients with a high risk of recurrence and poor survival in patients with cervical cancer with initial positive LNs.


Gynecologic Oncology | 2014

Comparison of clinical outcomes of adenocarcinoma and adenosquamous carcinoma in uterine cervical cancer patients receiving surgical resection followed by radiotherapy: A multicenter retrospective study (KROG 13-10)

Jae Myoung Noh; Won Soon Park; Young Seok Kim; Joo-Young Kim; Hak Jae Kim; J.H. Kim; Jin Hee Kim; Mee Sun Yoon; Jin Hwa Choi; Won Sup Yoon; Ji Yoon Kim; Seung Jae Huh

OBJECTIVE To evaluate the prognostic influence of adenocarcinoma (AC) and adenosquamous carcinoma (ASC) in patients with FIGO stage IB-IIA cervical cancer who received radical hysterectomy followed by adjuvant radiotherapy (RT) or concurrent chemoradiotherapy (CCRT). METHODS We analyzed 1323 patients who satisfied the following criteria: histologically proven squamous cell carcinoma (SCC), AC, or ASC of the uterine cervix; FIGO stage IB-IIA disease; no history of neoadjuvant chemotherapy; and a history of radical hysterectomy with pelvic lymph node (PLN) dissection, followed by postoperative pelvic RT at a dose ≥ 45 Gy. The median age was 50 years. Median RT dose delivered to the whole pelvis was 50.4 Gy, and 219 (16.6%) patients received brachytherapy at a median dose of 24 Gy. Concurrent chemotherapy was delivered to 492 (37.2%) patients. RESULTS Pathologic risk factors were not different according to pathologic subtype. The median follow-up duration was 75.7 months. Locoregional recurrence-free survival, relapse-free survival (RFS), and overall survival were significantly affected by histology, tumor size, PLN metastasis, parametrial invasion, lymphovascular invasion, and deep stromal invasion. The 5-year RFS rates were 83.7%, 66.5%, and 79.6% in patients with SCC, AC, and ASC histology, respectively (P<0.0001). By multivariate analysis, AC histology was the only significant prognostic factor affecting all survival outcomes. CONCLUSIONS AC histology was associated with poor survival outcomes in patients with FIGO stage IB-IIA cervical cancer who received adjuvant RT or CCRT. Prognosis of ASC histology was closer to that of SCC histology than that of AC histology.


Radiotherapy and Oncology | 2011

The metabolic response using 18F-fluorodeoxyglucose-positron emission tomography/computed tomography and the change in the carcinoembryonic antigen level for predicting response to pre-operative chemoradiotherapy in patients with rectal cancer.

Mee Sun Yoon; Sung-Ja Ahn; Byung-Sik Nah; Woong-Ki Chung; Ju-Young Song; Jae-Uk Jeong; Taek-Keun Nam

BACKGROUND AND PURPOSE To predict tumor regression in pre-operative chemoradiotherapy (CRT) using (18)F-fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT) and serum carcinoembryonic antigen (CEA) in patients with rectal cancer. MATERIALS AND METHODS The metabolic response of the tumor was assessed by determining the maximal standardized uptake value (SUV(max)), absolute difference (ΔSUV(max)), and SUV reduction ratio (SRR) on pre- and post-CRT PET/CT scans. The serum CEA, absolute difference (ΔCEA), and the CEA reduction ratio (CRR) were also determined. A receiver-operating characteristic (ROC) curve was generated. RESULTS Of all seventy two patients, mean pre- and post-CRT SUV(max) was 14.9 and 5.8, respectively. The mean pre- and post-CRT CEA level was 15.5 ng/ml and 5.4 ng/ml, respectively. Forty-three patients (59.8%) were classified as responders (Dworaks tumor regression grade 3-4) and 36 patients (50%) achieved tumor down-staging. ROC analysis showed that both post-CRT SUV(max) and SRR were predictive factors for responders (p=0.03 and p=0.02, respectively). A threshold of post-CRT SUV(max) was 5.4 and that of SRR was 53.1%. Pre-CRT SUV(max), ΔSUV(max), and all parameters in regard to CEA were not significant in ROC analysis. CONCLUSIONS The post-CRT SUV(max) and SRR are potential factors for predicting tumor response in pre-operative CRT. The patients with lower post-CRT SUV(max) and higher SRR could be expected to achieve maximum tumor regression after pre-operative CRT in this study.


International Journal of Radiation Oncology Biology Physics | 2012

Curative Chemoradiotherapy in Patients With Stage IVB Cervical Cancer Presenting With Paraortic and Left Supraclavicular Lymph Node Metastases

Ji-Yoon Kim; Joo-Young Kim; Jin Hee Kim; Mee Sun Yoon; J.H. Kim; Young Seok Kim

PURPOSE To evaluate the efficacy and toxicity of concurrent chemoradiotherapy (CCRT) with curative intent in patients with stage IVB cervical cancer initially presenting with paraortic and left supraclavicular lymph node metastases. METHODS AND MATERIALS The medical records of 25 patients with both paraortic and left supraclavicular lymph nodal metastases (group I) were reviewed and compared with those of 101 women with paraortic lymph node metastases alone (group II). Group I received a mean 59.4 Gy to the paraortic and left supraclavicular areas and 50.4 Gy to the pelvis, followed by 30 Gy of high-dose-rate brachytherapy in 6 fractions. Group II received the same dose to the paraortic area and pelvis followed by intracavitary brachytherapy. All patients received platinum-based chemotherapy simultaneously. RESULTS Of the 25 patients in group I, 16 (64%) experienced acute grade 3-4 hematologic toxicities, and 1 had a late grade 3 genitourinary toxicity. Complete responses, including the primary mass and pelvic, paraortic, and left supraclavicular lymph nodes, were observed in 13 patients (52%). At a median follow-up of 32 months for surviving patients, 3 experienced in-field failure, 6 showed distant failure, and 9 showed both. The 3-year overall and disease-free survival rates were 49% and 33%, respectively. In comparison, of the 101 patients in group II, 16 showed in-field failure, 14 experienced distant failure, and 11 showed both. The 3-year overall and disease-free survival rates were 69% and 57%, respectively. CONCLUSIONS Curative CCRT is feasible in patients with stage IVB cervical cancer presenting with paraortic and left supraclavicular lymph nodal metastases, with acceptable late toxicity and high response rates, despite high rates of acute hematologic toxicity.


Journal of Korean Medical Science | 2011

VEGF as a Predictor for Response to Definitive Chemoradiotherapy and COX-2 as a Prognosticator for Survival in Esophageal Squamous Cell Carcinoma

Mee Sun Yoon; Taek-Keun Nam; Ji-Shin Lee; Sang-Hee Cho; Ju-Young Song; Sung-Ja Ahn; Ik-Joo Chung; Jae-Uk Jeong; Woong-Ki Chung; Byung-Sik Nah

We investigated the patterns of pretreatment expression of the epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), and cyclooxygenase-2 (COX-2) by immunohistochemical staining and determined their correlation with treatment response and survival in 44 patients with esophageal squamous cell carcinoma (ESCC) treated with definitive concurrent chemoradiotherapy (CCRT). The definitive CCRT consisted of a median dose of 54 Gy (range: 40.0-68.4 Gy) and two cycles of concurrent administration of mostly 5-fluorouracil + cisplatinum. High expression of EGFR, VEGF, and COX-2 was found in 79.5%, 31.8%, and 38.6%, respectively. The Cox regression analysis for overall survival (OS) showed that both the treatment response and COX-2 expression were significant. The 3-yr OS rates of patients that achieved a complete response and those that did not were 46.7% and 5.3%, respectively (P = 0.006). The logistic regression analysis for treatment response with various parameters showed that only a high expression of VEGF was significantly associated with a complete response. Unlike other well-known studies, higher expression of VEGF was significantly correlated with a complete response to CCRT in this study. However, higher expression of COX-2 was significantly associated with shorter survival. These results suggest that VEGF might be a predictive factor for treatment response and COX-2 a prognostic factor for OS in patients with ESCC after definitive CCRT.


International Journal of Radiation Oncology Biology Physics | 2012

Long-Term Follow-Up of Preoperative Pelvic Radiation Therapy and Concomitant Boost Irradiation in Locally Advanced Rectal Cancer Patients: A Multi-Institutional Phase II Study (KROG 04-01)

Jong Hoon Lee; Dae Yong Kim; Taek-Keun Nam; Sei-Chul Yoon; Doo Seok Lee; Ji Won Park; Hee Jin Chang; Mee Sun Yoon; Jae-Uk Jeong; Hong Seok Jang

PURPOSE To perform a prospective phase II study to investigate the efficacy and safety of preoperative pelvic radiation therapy and concomitant small-field boost irradiation with 5-fluorouracil and leucovorin for 5 weeks in locally advanced rectal cancer patients. METHODS AND MATERIALS Sixty-nine patients with locally advanced, nonmetastatic, mid-to-lower rectal cancer were prospectively enrolled. They had received preoperative chemoradiation therapy and total mesorectal excision. Pelvic radiation therapy of 43.2 Gy in 24 fractions plus concomitant boost radiation therapy of 7.2 Gy in 12 fractions was delivered to the pelvis and tumor bed for 5 weeks. Two cycles of 5-fluorouracil and leucovorin were administered for 3 days in the first and fifth week of radiation therapy. The pathologic response, survival outcome, and treatment toxicity were evaluated for the study endpoints. RESULTS Of 69 patients, 8 (11.6%) had a pathologically complete response. Downstaging rates were 40.5% for T classification and 68.1% for N classification. At the median follow-up of 69 months, 36 patients have been followed up for more than 5 years. The 5-year disease-free survival (DFS) and overall survival rates were 66.0% and 75.3%, respectively. Higher pathologic T (P=.045) and N (P=.032) classification were significant adverse prognostic factors for DFS, and high-grade histology was an adverse prognostic factor for both DFS (P=.025) and overall survival (P=.031) on the multivariate analysis. Fifteen patients (21.7%) experienced grade 3 or 4 acute toxicity, and 7 patients (10.1%) had long-term toxicity. CONCLUSION Preoperative pelvic radiation therapy with concomitant boost irradiation with 5-fluorouracil and leucovorin for 5 weeks showed acceptable acute and long-term toxicities. However, the benefit of concomitant small-field boost irradiation for 5 weeks in rectal cancer patients was not demonstrated beyond conventional irradiation for 6 weeks in terms of tumor response and survival.


Radiotherapy and Oncology | 2015

Carcinoembryonic antigen has prognostic value for tumor downstaging and recurrence in rectal cancer after preoperative chemoradiotherapy and curative surgery: A multi-institutional and case-matched control study of KROG 14-12

Jong Hoon Lee; Dae Yong Kim; Kim Sh; Hyeon Min Cho; Byoung Yong Shim; Tae Hyun Kim; Sunyoung Kim; Ji Yeon Baek; Taek Keun Nam; Mee Sun Yoon; Jae Uk Jeong; Kyubo Kim; Eui Kyu Chie; Hong Seok Jang; Jae-Sung Kim; Jin Hee Kim; Bae Kwon Jeong

BACKGROUND AND PURPOSE The Korean Radiation Oncology Group evaluated the significance of carcinoembryonic antigen (CEA) levels both as a predictor of tumor response after CRT and as a prognosticator for recurrence-free survival. METHODS AND MATERIALS 1804 rectal cancer patients, staged cT3-4N0-2M0, participated in a multicenter study. The patients were administered preoperative radiation of 50.4 Gy in 28 fractions with 5-FU or capecitabine, followed by total mesorectal excision. Patients with elevated CEA levels (>5 ng/mL) were matched at a 1 (n=595):1 (n=595) ratio with patients with normal CEA (⩽5 ng/mL). The tumor response after CRT and the recurrence-free survival (RFS) rates were evaluated and compared between two arms. RESULTS An elevated CEA level (p<0.001) was determined to be a significant negative predictor of downstaging after CRT. The downstaging rate was 42.9% for normal CEA and 23.4% for elevated CEA. A multivariate analysis also revealed that cT (p=0.021) and cN classification (p=0.001), tumor size (p=0.002), and tumor location from the anal verge (p=0.006) were significant predictors for tumor downstaging. The 5-year RFS rates were significantly higher for the normal CEA arm than for the elevated CEA arm (74.2 vs. 63.5%, p<0.001). CONCLUSIONS Elevated CEA (>5 ng/mL) is a negative predictor of tumor downstaging after CRT and also has a negative impact on RFS in rectal cancer.


Radiotherapy and Oncology | 2016

Timely tumor response analysis after preoperative chemoradiotherapy and curative surgery in locally advanced rectal cancer: A multi-institutional study for optimal surgical timing in rectal cancer

Yoo-Kang Kwak; Kyubo Kim; Jong Hoon Lee; Kim Sh; Hyeon Min Cho; Dae Yong Kim; Tae Hyun Kim; Sunyoung Kim; Ji Yeon Baek; Taek Keun Nam; Mee Sun Yoon; Jae Uk Jeong; Eui Kyu Chie; Hong Seok Jang; Jae-Sung Kim

BACKGROUND AND PURPOSE The definite surgical timing in rectal cancer after preoperative chemoradiotherapy (CRT) has not yet been fully examined. We assess the tumor response and identify the optimal operation timing after preoperative CRT in rectal cancer. METHODS AND MATERIALS The study included data of 1786 patients with locally advanced rectal cancer (cT3-4N0-2M0). They received preoperative CRT followed by total mesorectal excision. Total radiation dose was 50.4Gy in 28 fractions. Interval time between preoperative CRT and surgery ranged from 2 to 26weeks, with a median interval of 7.2weeks. Primary endpoint was to evaluate the period of highest downstaging and pathological complete response (ypCR) rates to determine the optimal timing for curative surgery after CRT. RESULTS Downstaging rates peaked between 6 and 7weeks after CRT and declined afterward. ypCR rates increased from 5 to 6weeks after CRT and decreased after 9 to 10weeks. Downstaging rates were similar between the two arms showing 36.9% in the early arm (⩽7weeks) and 37.0% in the delayed arm (>7weeks). ypCR rates were significantly higher in the delayed arm, as compared to the early arm (12.3% vs. 8.6%, p=0.011). The delayed arm had higher sphincter preservation rates than the early arm with a marginal significance (92.4% vs. 89.9%, p=0.078). There was no statistically significant difference regarding relapse-free survival and overall survival between the two arms. CONCLUSIONS ypCR rates increased after 5weeks and decreased after 10weeks and the delayed (>7weeks after CRT) group showed significantly increased ypCR rates than the early arm (⩽7weeks after CR). The optimal timing for curative surgery in rectal cancer when tumor response is maximal is after 7weeks and before 10weeks following preoperative CRT.


Cancer Research and Treatment | 2014

The Role of Radiotherapy in the Treatment of Gastric Mucosa-Associated Lymphoid Tissue Lymphoma

Taek-Keun Nam; Jae-Sook Ahn; Yoo-Duk Choi; Jae-Uk Jeong; Yong-Hyeob Kim; Mee Sun Yoon; Ju-Young Song; Sung-Ja Ahn; Woong-Ki Chung

Purpose To assess radiotherapy for patients with early stage gastric mucosa-associated lymphoid tissue (MALT) lymphoma with respect to survival, treatment response, and complications. Materials and Methods Enrolled into this study were 48 patients diagnosed with gastric MALT lymphoma from January 2000 to September 2012. Forty-one patients had low grade and seven had mixed component with high grade. Helicobacter pylori eradication was performed in 33 patients. Thirty-four patients received radiotherapy alone. Ten patients received chemotherapy before radiotherapy, and three patients underwent surgery followed by chemotherapy and radiotherapy. One patient received surgery followed by radiotherapy. All patients received radiotherapy of median dose of 30.6 Gy. Results The duration of follow-up ranged from 6 to 158 months (median, 48 months). Five-year overall survival and cause-specific survival rates were 90.3% and 100%. All patients treated with radiotherapy alone achieved pathologic complete remission (pCR) in 31 of the low-grade and in three of the mixed-grade patients. All patients treated with chemotherapy and/or surgery prior to radiotherapy achieved pCR except one patient who received chemotherapy before radiotherapy. During the follow-up period, three patients developed diffuse large B-cell lymphoma in the stomach, and one developed gastric adenocarcinoma after radiotherapy. No grade 3 or higher acute or late complications developed. One patient, who initially exhibited gastroptosis, developed mild atrophy of left kidney. Conclusion These findings indicate that a modest dose of radiotherapy alone can achieve a high cure rate for low-grade and even mixed-grade gastric MALT lymphoma without serious toxicity. Patients should be carefully observed after radiotherapy to screen for secondary malignancies.


Acta Oto-laryngologica | 2008

Concurrent chemoradiotherapy with cisplatin and fluorouracil for locally advanced hypopharyngeal carcinoma

Mee Sun Yoon; Woong-Ki Chung; Sung-Ja Ahn; Taek-Keun Nam; Byung-Sik Nah; Ju-Young Song; Sang Cheol Lim; Joon Kyoo Lee

Conclusions. The concurrent administration of cisplatin and fluorouracil (CCRT) during radiotherapy after induction chemotherapy had better results than induction chemotherapy followed by radiotherapy alone (CT+RT) for overall survival, laryngeal preservation, and locoregional control in patients with locally advanced hyopharyngeal cancer. Objectives. To report treatment results comparing CCRT with CT+RT in locally advanced hypopharyngeal cancer. Patients and methods. Sixty-six consecutive patients treated with curative intent were analyzed retrospectively. Thirty-eight patients were treated with induction chemotherapy followed by definitive RT, and 28 patients with induction chemotherapy followed by concurrent chemoradiotherapy. All patients had more than three cycles of continuous infusion of cisplatin and 5-fluorouracil every 3 weeks. The median dose of irradiation was 70 Gy in the CT+RT group and 68.4 Gy in the CCRT group, respectively. Results. The overall 5-year survival rates were 24% for the CT+RT group and 42% for the CCRT group (p=0.031). The 3-year pharyngolaryngectomy-free survival rates were 32% for the CT+RT group and 63% for the CCRT group (p=0.032). The 3-year locoregional control rate for CCRT was significantly better than that for the CT+RT (52% vs 23%, p=0.004). Acute hematologic toxicity appeared in 39% of the CT+RT patients and 75% of the CCRT patients.

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Woong-Ki Chung

Chonnam National University

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Taek-Keun Nam

Chonnam National University

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Ju-Young Song

Chonnam National University

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Jae-Uk Jeong

Chonnam National University

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Sung-Ja Ahn

Chonnam National University

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Jong Hoon Lee

Catholic University of Korea

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Byung-Sik Nah

Chonnam National University

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