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Dive into the research topics where Ki Chang Keum is active.

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Featured researches published by Ki Chang Keum.


International Journal of Radiation Oncology Biology Physics | 1999

Combined transcatheter arterial chemoembolization and local radiotherapy of unresectable hepatocellular carcinoma.

Jinsil Seong; Ki Chang Keum; Kwang Hyub Han; Do Yun Lee; Jong Tae Lee; Chae Yoon Chon; Young Myoung Moon; C.O. Suh; Gwi Eon Kim

PURPOSE The best prognosis in hepatocellular carcinoma (HCC) can be achieved with surgical resection; however, the number of resected cases are limited due to advanced lesions or associated liver disease. The purpose of this study was to investigate the efficacy and toxicity of a prospective trial of combined transcatheter arterial chemoembolization (TACE) and local radiotherapy (RT) in unresectable HCC. METHODS AND MATERIALS Patients with histologically proven unresectable HCC due to either advanced lesions or associated cirrhosis were eligible. From March 1992 to August 1994, 30 patients were entered into this study. TACE was performed with Lipiodol (5 ml) and doxorubicin (Adriamycin ; 50 mg), followed by gelatin sponge particle (Gelfoam) embolization. Local RT was started within 7-10 days following TACE. Mean tumor dose was 44.0+/-9.3 Gy in daily 1.8 Gy fractions. Response was assessed by computerized tomography (CT) scan 4-6 weeks following completion of the treatment and then at 1-3-month intervals. Survival was calculated from the start of TACE using the Kaplan-Meier method. RESULTS An objective response was observed in 19 patients, giving a response rate of 63.3%. Distant metastasis occurred in 10 patients, with 8 in the lung only and 2 in both lung and bone. Survival rates at 1, 2, and 3 years were 67%, 33.3%, and 22.2%, respectively. Median survival was 17 months. There were 6 patients surviving more than 3 years. Toxicity included transient elevation of liver function tests in all patients, fever in 20, thrombocytopenia in 4, and nausea and vomiting in 1. There was no treatment-related death. CONCLUSION Combined TACE and local RT is feasible and tolerable. It gives a 63.3% response rate with median survival of 17 months. We feel that this regimen would be a new promising modality in unresectable HCC. Further study is required to compare the therapeutic efficacy of this regimen to TACE alone.


International Journal of Radiation Oncology Biology Physics | 2009

Risk Factors and Dose-Effect Relationship for Mandibular Osteoradionecrosis in Oral and Oropharyngeal Cancer Patients

Ik Jae Lee; Woong Sub Koom; Chang Geol Lee; Yong Bae Kim; Sei Whan Yoo; Ki Chang Keum; Gwi Eon Kim; Eun Chang Choi; In Ho Cha

PURPOSE To analyze risk factors and the dose-effect relationship for osteoradionecrosis (ORN) of the mandible after radiotherapy of oral and oropharyngeal cancers. MATERIALS AND METHODS One-hundred ninety-eight patients with oral (45%) and oropharyngeal cancer (55%) who had received external radiotherapy between 1990 and 2000 were retrospectively reviewed. All patients had a dental evaluation before radiotherapy. The median radiation dose was 60 Gy (range, 16-75 Gy), and the median biologically effective dose for late effects (BED(late)) in bone was 114 Gy(2) (range, 30-167 Gy(2)). RESULTS The frequency of ORN was 13 patients (6.6%). Among patients with mandibular surgery, eight had ORN at the surgical site. Among patients without mandibular surgery, five patients had ORN on the molar area of the mandible. The median time to ORN was 22 months (range, 1-69 months). Univariate analysis revealed that mandibular surgery and Co-60 were significant risk factors for ORN (p = 0.01 and 0.04, respectively). In multivariate analysis, mandibular surgery was the most important factor (p = 0.001). High radiation doses over BED 102.6 Gy(2) (conventional dose of 54 Gy at 1.8 Gy/fraction) were also a significant factor for ORN (p = 0.008) and showed a positive dose-effect relationship in logistic regression (p = 0.04) for patients who had undergone mandibular surgery. CONCLUSIONS Mandibular surgery was the most significant risk factor for ORN of mandible in oral and oropharyngeal cancers patients. A BED of 102.6 Gy(2) or higher to the mandible also significantly increases the risk of ORN.


International Journal of Radiation Oncology Biology Physics | 2010

Tumor Volume Changes Assessed by Three-Dimensional Magnetic Resonance Volumetry in Rectal Cancer Patients After Preoperative Chemoradiation: The Impact of the Volume Reduction Ratio on the Prediction of Pathologic Complete Response

Jeonghyun Kang; Young Chul Kim; Hyunki Kim; Young Wan Kim; Hyuk Hur; Jin Soo Kim; Byung Soh Min; Hogeun Kim; Joon Seok Lim; Jinsil Seong; Ki Chang Keum; Nam Kyu Kim

PURPOSE The aim of this study was to determine the correlation between tumor volume changes assessed by three-dimensional (3D) magnetic resonance (MR) volumetry and the histopathologic tumor response in rectal cancer patients undergoing preoperative chemoradiation therapy (CRT). METHODS AND MATERIALS A total of 84 patients who underwent preoperative CRT followed by radical surgery were prospectively enrolled in the study. The post-treatment tumor volume and tumor volume reduction ratio (% decrease ratio), as shown by 3D MR volumetry, were compared with the histopathologic response, as shown by T and N downstaging and the tumor regression grade (TRG). RESULTS There were no significant differences in the post-treatment tumor volume and the volume reduction ratio shown by 3D MR volumetry with respect to T and N downstaging and the tumor regression grade. In a multivariate analysis, the tumor volume reduction ratio was not significantly associated with T and N downstaging. The volume reduction ratio (>75%, p = 0.01) and the pretreatment carcinoembryonic antigen level (< or =3 ng/ml, p = 0.01), but not the post-treatment volume shown by 3D MR (< or = 5 ml), were, however, significantly associated with an increased pathologic complete response rate. CONCLUSION More than 75% of the tumor volume reduction ratios were significantly associated with a high pathologic complete response rate. Therefore, limited treatment options such as local excision or simple observation might be considered after preoperative CRT in this patient population.


American Journal of Otolaryngology | 1999

Clinical significance of neck node metastasis in squamous cell carcinoma of the maxillary antrum

Gwi Eon Kim; Eun Ji Chung; John Jihoon Lim; Ki Chang Keum; Sangwook Lee; Jae Ho Cho; Chang Geol Lee; A. Eun Chang Choi

PURPOSE To further clarify the clinical significance of neck node metastasis in squamous cell carcinoma of the maxillary sinus (maxillary SCC). MATERIALS AND METHODS The medical charts of the 116 patients with maxillary SCC were retrospectively reviewed. Twelve patients (10.3%) presented initially with neck node metastases, and 14 (13.5%) of 104 node-negative patients subsequently developed regional recurrence during the follow-up period. The high-risk factors for neck node metastasis, patterns of regional failure, and survival for node-positive patients were analyzed with the patient cohort that had largely been treated with radiation alone. RESULTS Of the various factors, the tumor extension to the nasopharynx or oral cavity was the statistically significant determinants predictive of neck node metastasis at the initial diagnosis. During the follow-up period, regional failure was far less common than local failure (19.0% v 68.1%), and the majority of regional failures were accompanied by local recurrences. The oral cavity extension and control status of local disease were the high-risk factors for subsequent development of regional recurrence in node-negative patients. The overall 5-year survival rate for node-positive patients (16.7%) showed a poorer outcome compared with that for node-negative patients (31.3%), but it was similar to that of T4N0 patients (26.6%). Although patients who subsequently developed neck node recurrence during follow-up represented a dismal prognosis, uncontrolled local diseases in these patients still remained a major problem, resulting in a poor prognosis. CONCLUSIONS Despite an unfavorable prognosis of patients with neck node metastasis, an aggressive trial to achieve maximum local control of the primary tumor was considered to be more important than elective neck treatments.


European Radiology | 2012

Perfusion MRI for the prediction of treatment response after preoperative chemoradiotherapy in locally advanced rectal cancer

Joon Seok Lim; Daehong Kim; Song Ee Baek; Sungmin Myoung; Junjeong Choi; Sang Joon Shin; Myeong Jin Kim; Nam Kyu Kim; Jinsuk Suh; Ki Whang Kim; Ki Chang Keum

ObjectivesTo evaluate the utility of perfusion MRI as a potential biomarker for predicting response to chemoradiotherapy (CRT) in locally advanced rectal cancer.MethodsThirty-nine patients with primary rectal carcinoma who were scheduled for preoperative CRT were prospectively recruited. Perfusion MRI was performed with a 3.0-T MRI system in all patients before therapy, at the end of the 2nd week of therapy, and before surgery. The Ktrans (volume transfer constant) and Ve (extracellular extravascular space fraction) were calculated.ResultsBefore CRT, the mean tumour Ktrans in the downstaged group was significantly higher than that in the non-downstaged group (P = 0.0178), but there was no significant difference between tumour regression grade (TRG) responders and TRG non-responders (P = 0.1392). Repeated-measures analysis of variance (ANOVA) showed significant differences for evolution of Ktrans values both between downstaged and non-downstaged groups (P = 0.0215) and between TRG responders and TRG non-responders (P = 0.0001). Regarding Ve, no significant differences were observed both between downstaged and non-downstaged groups (P = 0.689) or between TRG responders and TRG non-responders (P = 0.887).ConclusionPerfusion MRI of rectal cancer can be useful for assessing tumoural Ktrans changes by CRT. Tumours with high pre-CRT Ktrans values tended to respond favourably to CRT, particularly in terms of downstaging criteria.Key Points• Perfusion MRI can now assess therapeutic response of tumours to therapy.• Tumours with high initialKtransvalues responded favourably to chemoradiotherapy.• Perfusion MRI of rectal cancer may help with decisions about management.


Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2004

Clinical relevance of three subtypes of primary sinonasal lymphoma characterized by immunophenotypic analysis

Gwi Eon Kim; Woong Sub Koom; Woo Ick Yang; Sangwook Lee; Ki Chang Keum; Chang Geol Lee; Chang Ok Suh; Jee Sook Hahn; Jae Kyung Roh; Joo Hang Kim

The purpose of this study was to investigate the clinical relevance of subtypes categorized by immunophenotypic analysis in primary sinonasal lymphomas.


American Journal of Otolaryngology | 1999

Adenoid cystic carcinoma of the maxillary antrum

Gwi Eon Kim; Hee Chul Park; Ki Chang Keum; Chang Geol Lee; Chang Ok Suh; Won Hur; Kwang Moon Kim; Won Pyo Hong

PURPOSE To investigate characteristic clinical features and outcome for patients with adenoid cystic carcinoma (ACC) of the maxillary antrum. PATIENTS AND METHODS Twenty-two patients with ACC of the maxillary antrum were initially treated with surgery alone (3 patients), radiation alone (9 patients), or a combination of surgery and radiation (10 patients). Salvage treatment for initial failure was individualized. Patterns of failure, survival, and prognostic factors were retrospectively analyzed. RESULTS The most frequent site of failure was local recurrence at the primary site (72.7%). All patients treated with either surgery alone or radiation alone experienced one or more local recurrences, whereas patients who received planned combined surgery and radiation had a much lower local recurrence rate (40%). Neck node failure (4.6%) was an uncommon event, whereas distant metastases were clinically documented in seven patients (32%). Most of the treatment failures appeared within 5 years, but treatment failures after 5 years were not uncommon. The overall survival and disease-free survival rates at 10 years were 37.6% and 13.6%, respectively. Clinicopathological factors, such as location of primary tumor, tumor stage, and histological grade were of no value in predicting a favorable survival. The significant prognostic factors influencing 10-year survival were the pathological finding of perineural invasion and the initial mode of treatment. CONCLUSION ACC of the maxillary antrum represented a unique natural history characterized by a more aggressive tumor behavior and an unfavorable prognosis. Combined surgery and radiotherapy is recommended for optimal local control and survival.


Cancer | 2009

Therapeutic effect of recombinant human epidermal growth factor (RhEGF) on mucositis in patients undergoing radiotherapy, with or without chemotherapy, for head and neck cancer: a double-blind placebo-controlled prospective phase 2 multi-institutional clinical trial.

Hong Gyun Wu; Si Yeol Song; Yeon Sil Kim; Young Taek Oh; Chang Geol Lee; Ki Chang Keum; Yong Chan Ahn; Sangwook Lee

We evaluated the efficacy of topically applied human recombinant epidermal growth factor (rhEGF) for the treatment of oral mucositis induced by radiotherapy (RT), with or without chemotherapy, in patients with head and neck cancer.


Journal of Magnetic Resonance Imaging | 2011

Comparison of diffusion‐weighted MRI and MR volumetry in the evaluation of early treatment outcomes after preoperative chemoradiotherapy for locally advanced rectal cancer

Young Chul Kim; Joon Seok Lim; Ki Chang Keum; Kyung Ah Kim; Sungmin Myoung; Sang Joon Shin; Myeong Jin Kim; Nam Kyu Kim; Jinsuk Suh; Ki Whang Kim

To compare diffusion‐weighted imaging (DWI) and magnetic resonance (MR) volumetry for predicting treatment outcomes of locally advanced rectal cancers with preoperative chemoradiotherapy (CRT).


Radiation Oncology | 2010

Clinical outcomes for T1-2N0-1 oral tongue cancer patients underwent surgery with and without postoperative radiotherapy.

Su Jung Shim; Jihye Cha; Woong Sub Koom; Gwi Eon Kim; Chang Geol Lee; Eun Chang Choi; Ki Chang Keum

BackgroundThe aim of this study was to assess the results of curative surgery with and without radiotherapy in patients with T1-2N0-1 oral tongue squamous cell carcinoma (OSCC) and to evaluate survival and prognostic factors.MethodsRetrospective analysis of 86 patients with T1-2N0-1 OSCC who received surgery between January 2000 and December 2006. Fourteen patients (16.3%) received postoperative radiotherapy (PORT). Patient characteristics, tumor characteristics, treatment modality, failure patterns, and survival rates were analyzed.ResultsThe median follow-up was 45 months. The five-year overall survival (OS) and disease-free survival (DFS) rates were 80.8% and 80.2%, respectively. Higher tumor grade and invasion depth ≥ 0.5 cm were the significant prognostic factors affecting five-year OS and DFS (OS rate; 65% vs. 91%, p = 0.001 for grade; 66% vs. 92%, p = 0.01 for invasion depth: DFS rate; 69% vs. 88%, p = 0.005 for grade; 66% vs. 92%, p = 0.013 for invasion depth). In the risk group, there was no local failure in patients with postoperative radiotherapy.ConclusionsIn T1-2N0-1 OSCC, factors that affected prognosis after primary surgery were higher tumor grade and deep invasion depth over 0.5 cm. Postoperative radiotherapy should be considered in early oral tongue cancer patients with these high-risk pathologic features.

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