Woohyun Jung
Seoul National University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Woohyun Jung.
Journal of Breast Cancer | 2012
Woohyun Jung; Eunyoung Kang; Sun Mi Kim; Dongwon Kim; Yoonsun Hwang; Young Sun; Cha Kyong Yom; Sung-Won Kim
Purpose Re-excisions after breast-conserving surgery (BCS) for breast cancer cause delays in the adjuvant treatment, increased morbidity, and leads to poor aesthetic results. Thus, efforts to reduce the re-excision rate are essential. This study aimed to conclusively determine the re-excision rate and the factors associated with re-excision after BCS. Methods We retrospectively reviewed the medical records and pathological reports of 711 cases that underwent BCS for early-stage breast cancer. Univariate and multivariate analyses were performed. Results Of the 711 cases of BCS, 71 (10.0%) required re-excision. Patients in the re-excision group were younger than those in the no re-excision group. Non-palpable lesions, the presence of non-mass-like enhancement at magnetic resonance imaging, multifocality, the presence of a ductal carcinoma in situ (DCIS) component, and an infiltrative tumor border were also significantly associated with re-excision. Multivariate analysis indicated that younger age, non-palpable lesions, multifocal lesions, and the presence of a DCIS component were factors which were independently associated with re-excision. Tumors located in the lower inner quadrant had a relatively high involved resection margin rate as well as a narrow resection margin width, especially at the superior and medial margins. Lateral margins showed a tendency toward a wider resection margin width. Conclusion At our institution, the rate of re-excision was low despite the lack of an intraoperative frozen section. Patients with non-palpable or multifocal tumors, a DCIS component, or those who were younger than 50 years were more likely to require re-excision after BCS. These factors should be considered when planning surgical management of early-stage breast cancer. Positive resection margin rates and margin widths differed on a directional basis based on tumor location, and these differences were considerable.
Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science | 1996
Woohyun Jung; Huesup Song; Sang Whan Park; Doh-Yeon Kim
The contact angles of liquid Al on polycrystalline Al2O3 determined by the conventional sessile drop method were obtuse (∼120 deg) up to 900 °C but decreased rapidly at 1000 °C. When the molten Al was squeezed through a narrow orifice and dropped onto the substrate, the contact angle at 900 °C was 77 deg and decreased linearly with temperature. At 1000 °C and 1100 °C, the contact angles decreased slowly with holding times up to 50 and 6 hours, respectively. At 1200 °C, the contact angle also decreased with holding time up to 40 minutes, after which it oscillated, resulting in a ring pattern on the substrate. The structural change of the Al2O3 substrate surface is suggested to be an important variable that determines the wetting behavior of the Al-Al2O3 system.
British Journal of Cancer | 2015
Seung Hyun Ma; Woohyun Jung; Elisabete Weiderpass; Jieun Jang; Y. S. Hwang; Chunghyun Ahn; Kwang Pil Ko; Soung Hoon Chang; Hai Rim Shin; Keun-Young Yoo; Sue K. Park
Background:Helicobacter pylori are major carcinogen of gastric cancer, but the associations among gastric cancer, H. pylori infection status, and alcohol consumption are not fully described. This study aimed to clarify how H. pylori infection status affects the association between alcohol consumption and gastric cancer risk.Methods:We selected 949 case–cohort participants from the 18 863 Korean Multi-center Cancer Cohort (KMCC) populations. Gastric cancer incidence inside and outside of the subcohort were 12 and 254 cases, respectively. Seropositivities for CagA, VacA, and H. pylori infection were determined by performing immunoblot assays. Weighted Cox regression models were used to calculate hazard ratios and 95% confidence intervals (CIs).Results:Relative to non-drinking, heavy drinking (⩾7 times a week), and binge drinking (⩾55 g alcohol intake per occasion) showed a 3.48-fold (95% CI, 1.13–10.73) and 3.27-fold (95% CI, 1.01–10.56) higher risk in subjects not previously infected by H. pylori. There was no significant association between drinking pattern and gastric cancer risk in H. pylori IgG seropositive subjects. An increased risk for gastric cancer in heavy- and binge-drinking subjects were also present in subjects not infected by CagA- or VacA-secreting H. pylori.Conclusions:Heavy and binge alcohol consumption is an important risk factor related to an increasing incidence of gastric cancer in a population not infected by H. pylori.
British Journal of Surgery | 2015
M.J. Kang; Jungwoo Jang; Ye Rim Chang; Woohyun Jung; S.-W. Kim
The fate of the portal vein (PV) after pancreatoduodenectomy, especially its long‐term patency and associated complications, has received little attention. The aim of this study was to explore the long‐term patency rate of the PV after pancreatoduodenectomy, focusing on risk factors for PV stenosis/occlusion and associated complications.
Journal of Hepato-biliary-pancreatic Sciences | 2015
Jae Ri Kim; Jin-Young Jang; Mee Joo Kang; Taesung Park; Seung Yeoun Lee; Woohyun Jung; Jihoon Chang; Y.C. Shin; Young-Min Han; Sun-Whe Kim
Little is known about the prognostic significance of serum carbohydrate antigen (CA) 19‐9 and carcinoembryonic antigen (CEA) concentrations for predicting malignancy in patients with intraductal papillary mucinous neoplasm (IPMN) of pancreas.
Gut and Liver | 2016
Woohyun Jung; Jin-Young Jang; Mee Joo Kang; Ye Rim Chang; Yong Chan Shin; Jihoon Chang; Sun-Whe Kim
Background/Aims Extended cholecystectomy is generally recommended for patients with T2 gallbladder cancer. However, few studies have assessed the extent of resection relative to T2 gallbladder tumor location. This study analyzed the effects of surgical methods and tumor location on survival outcomes and tumor recurrence in patients with T2 gallbladder cancer. Methods Clinicopathological characteristics, extent of resection, survival rates, and recurrence patterns were retrospectively analyzed in 88 patients with pathologically confirmed T2 gallbladder cancer. Results The 5-year disease-free survival rate was 65.0%. Multivariate analysis showed that lymph node metastasis was the only independent risk factor for poor 5-year disease-free survival rate. Survival outcomes were not associated with tumor location. Survival tended to be better in patients who underwent extended cholecystectomy than in those who underwent simple cholecystectomy. Recurrence rate was not affected by surgical method or tumor location. Systemic recurrence was more frequent than local recurrence without distant recurrence. Gallbladder bed recurrence and liver recurrence were relatively rare, occurring only in patients with liver side tumors. Conclusions Extended cholecystectomy is the most appropriate treatment for T2 gallbladder cancer. However, simple cholecystectomy with regional lymph node dissection may be appropriate for patients with serosal side tumors.
Hpb | 2016
Woohyun Jung; Jin-Young Jang; Mee Joo Kang; Ye Rim Chang; Yong Chan Shin; Jihoon Chang; Sun-Whe Kim
BACKGROUND Computed tomography and serum tumor markers have limited value in detecting recurrence after curative surgery of pancreatic cancer. This study evaluated the clinical utility of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) in diagnosing recurrence. METHODS One hundred ten patients underwent curative resection of pancreatic cancer were enrolled. The diagnostic value of abdominal computed tomography (CT), PET-CT and serum carbohydrate antigen (CA) 19-9 concentration were compared. The prognostic value of SUVmax on PET-CT was evaluated. RESULTS PET-CT showed relatively higher sensitivity (84.5% vs. 75.0%) and accuracy (84.5% vs. 74.5%) than CT, whereas PET-CT plus CT showed greater sensitivity (97.6%) and accuracy (90.0%) than either alone. In detecting distant recurrences, PET-CT showed higher sensitivity (83.1% vs. 67.7%) than CT. Nineteen patients showed recurrences only on PET-CT, with eleven having invisible or suspected benign lesions on CT, and eight had recurrences in areas not covered by CT. SUVmax over 3.3 was predictive of poor survival after recurrence. CONCLUSIONS PET-CT in combination with CT improves the detection of recurrence. PET-CT was especially advantageous in detecting recurrences in areas not covered by CT. If active post-operative surveillance after curative resection of pancreatic cancer is deemed beneficial, then it should include PET-CT combined with CT.
Medicine | 2016
Hyung-Jun Im; Suthet Oo; Woohyun Jung; Jin-Young Jang; Sun-Whe Kim; Gi Jeong Cheon; Keon Wook Kang; June-Key Chung; Eun-Kyung Kim; Dong Soo Lee
AbstractIn this study, we aimed to evaluate prognostic value of metabolic and volumetric parameters measured from 18F fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in patients with resectable pancreatic cancer.Fifty-one patients with resectable pancreatic cancer who underwent FDG-PET/CT and curative operation were retrospectively enrolled. The maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured from FDG-PET/CT. Association between FDG-PET/CT and clinicopathologic parameters was evaluated. The prognostic values of the FDG-PET/CT and clinicopathologic parameters for recurrence-free survival (RFS) and overall survival (OS) were assessed by univariate and multivariate analyses.The 51 enrolled patients were followed up for a median of 21 months (mean ± SD: 23 ± 16 months, range: 1–78 months) with 33 (65%) recurrences and 30 (59%) deaths during the period. SUVmax, MTV, and TLG were associated with Tumor node metastasis (TNM) stage and presence of lymph node metastasis. MTV and TLG were associated with presence of lymphovascular invasion, whereas SUVmax was not. On the univariate analysis, SUVmax, MTV, and TLG were associated with RFS and OS. Also, lymph node metastasis and TNM stage were associated with OS on the univariate analysis. On multivariate analysis, MTV and TLG were independent prognostic factors for RFS and OS. SUVmax was an independent prognostic factor for OS, but not for RFS.Metabolic tumor volume and TLG were independently predictive of RFS and OS in resectable pancreatic cancer. SUVmax was an independent factor for OS, but not for RFS.
Journal of Hepato-biliary-pancreatic Sciences | 2016
Jihoon Chang; Jin-Young Jang; Kyoung Bun Lee; Mee Joo Kang; Woohyun Jung; Yong Chan Shin; Sun-Whe Kim
Current guidelines for gallbladder cancer (GBC) contain controversies and some reported no survival improvement in GBC during 20 years. This study was designed to explore the chronologic change of survival outcomes in GBC and prognostic factors.
ieee international underwater technology symposium | 2017
Hujae Choi; Woohyun Jung; Nakwan Kim
This paper is about autonomous ball launcher system on Autonomous Surface Vehicle. The work was done for ‘Detect and Deliver’ task which is a part of 2016 Maritime RobotX Challenge. In this task, ASV should propel or insert racquet balls through the target holes on the face which has assigned shape. To perform the task, pneumatic launcher system was developed. The launcher system is divided into compression module and launching module. Camera image processing is performed to aim at the target hole. The system development process and task carrying out strategy are demonstrated in the paper. The result was validated by experiment. At the end of the paper competition result is also presented.