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Dive into the research topics where Yun-Chung Cheung is active.

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Featured researches published by Yun-Chung Cheung.


Journal of Magnetic Resonance Imaging | 2003

Correlation of dynamic contrast enhancement MRI parameters with microvessel density and VEGF for assessment of angiogenesis in breast cancer

Min-Ying Su; Yun-Chung Cheung; John P. Fruehauf; Hon Yu; Orhan Nalcioglu; Eugene Mechetner; Ainura Kyshtoobayeva; Shin-Cheh Chen; Swei Hsueh; Christine E. McLaren; Yung‐Liang Wan

To investigate the association between parameters obtained from dynamic contrast enhanced MRI (DCE‐MRI) of breast cancer using different analysis approaches, as well as their correlation with angiogenesis biomarkers (vascular endothelial growth factor and vessel density).


Breast Cancer Research and Treatment | 2003

Monitoring the size and response of locally advanced breast cancers to neoadjuvant chemotherapy (weekly paclitaxel and epirubicin) with serial enhanced MRI.

Yun-Chung Cheung; Shih-Cheh Chen; Min-Ying Su; Lai-Chu See; Swei Hsueh; Hsien-Kun Chang; Yung-Chang Lin; Chien-Sheng Tsai

AbstractPurpose. To determine if early cancer size reduction seen on enhanced magnetic resonance imaging (MRI) can serve as a response predictor and to correlate final tumor sizes on MRI and excised gross tumor size to microscopic findings in patients with locally advanced breast cancers treated with preoperative neoadjuvant chemotherapy. Methods and materials. Thirty-three patients with advanced breast cancer entered this prospective chemotherapeutic study. Serial, dynamic, enhanced MRI was performed before chemotherapy induction, after the first course of chemotherapy and after the third course of chemotherapy prior to surgery. Responses were measured by image subtraction of tumor size on subsequent axial MRIs using the response evaluation criteria in solid tumors (RECIST). Early tumor size reduction, percentage of relative early tumor size reduction and final tumor size response were calculated and analyzed statistically. Sizes of residual tumors measured on MRI and gross tumors in excised breasts were correlated with microscopic findings. Results. Based on tumor sizes measured with enhanced MRI, four complete responders (CR), 19 partial responders (PR) and 10 non-responder were documented. Twelve (52%) of the 23 responders (CR and PR) had reached the criteria for PR (≥30% size reduction) after the first course of chemotherapy. All CR had a marked early size reduction (ESR) of more than 45%. Using the receiver operating characteristic (ROC) curve, a good cutoff point for early tumor size reduction was 7.4 cm, with a false positive rate of 0.1 and a false negative rate of 0.13. The percentage of ESR was 8.8%, with a false positive rate of 0.1 and a false negative rate of 0.09. Residual tumor size on MRI correlated well with microscopic findings (r = 0.982, p < 0.001) and gross tumor size in excised breasts correlated moderately with microscopic findings (r = 0.640, p < 0.001). Conclusion. Serial, dynamic, enhanced MRI monitoring of chemotherapeutic response in patients with locally advanced breast cancer can be used to assess early response to chemotherapy and post-chemotherapy tumor size change. Although the residual tumor size on MRI correlated well with the microscopic findings, surgical determination of residual cancer load is still recommended to avoid underestimation.


Journal of Vascular and Interventional Radiology | 2003

Factors Affecting Diagnostic Accuracy of CTguided Coaxial Cutting Needle Lung Biopsy: Retrospective Analysis of 631 Procedures

Kee-Min Yeow; Pei-Kwei Tsay; Yun-Chung Cheung; Kar-Wai Lui; Kuang-Tse Pan; Andy Shau-Bin Chou

PURPOSE To analyze variables affecting diagnostic accuracy of computed tomography (CT)-guided percutaneous coaxial cutting needle biopsy of lung lesions. MATERIALS AND METHODS A retrospective analysis of factors affecting diagnostic accuracy of CT-guided percutaneous coaxial cutting needle lung biopsy was performed in 631 consecutive procedures with confirmed final diagnoses. Benign and malignant needle biopsy results were cross-examined with correct and incorrect final outcomes to determine diagnostic accuracy. Factors affecting diagnostic accuracy were determined by multivariate logistic regression analysis of variables thought to affect diagnostic accuracy. A P value less than 0.05 was interpreted as statistically significant. RESULTS The overall diagnostic accuracy of CT-guided percutaneous coaxial cutting needle biopsy of lung lesions was 95% (95% CI: 92.7%-96.2%). Sensitivity was 93%, specificity 98%, negative predictive value 6%, positive predictive value 99%, false-positive rate 0.7%, and false-negative rate 15%. The factors affecting diagnostic accuracy were final diagnoses (benign, 86%; malignant, 99%; chi(2) test, P < 0.001) and lesion size (lesions <1.5 cm, 84%; lesions 1.5-5.0 cm, 96%; lesions >5 cm, 93%; chi(2) test, P = 0.06). CONCLUSION Benign lung lesions, lung lesions smaller than 1.5 cm (which pose technical difficulty), and lung lesions larger than 5 cm (which are associated with a higher necrosis rate) affect diagnostic accuracy of CT-guided percutaneous coaxial cutting needle biopsy of lung lesions.


Annals of Surgery | 2003

Intraoperative Ultrasonographically Guided Excisional Biopsy or Vacuum-Assisted Core Needle Biopsy for Nonpalpable Breast Lesions

Shin-Cheh Chen; Horng-Ren Yang; Tsann-Long Hwang; Miin-Fu Chen; Yun-Chung Cheung; Swei Hsueh

Objective: To compare duration and rates of underestimation and complete excision for nonpalpable breast lesions using either intraoperative ultrasonographically guided excisioned biopsy (IUGE) or directional vacuum-assisted biopsy (DVAB). Summary Background Data: Percutaneous ultrasonography-guided core needle biopsy is preferable to stereotactic biopsy for treatment of nonpalpable breast lesions; however, underestimation and false-negative results can occur, and rebiopsy may be required. To date, however, there has been no comparison of these two procedures in terms of diagnostic accuracy and duration. Methods: For 4 consecutive years, IUGE was performed for 104 nonpalpable breast lesions and DVAB for 128 lesions at Chang Gung Memorial Hospital. Of the DVAB cases, the handheld mammotome was used for 53 procedures, with all lesions removed as completely as possible. The duration of the two procedures was calculated from initial skin incision until completion of wound closure. Most of the patients with benign pathology underwent ultrasonographic examination at 3 months after surgery, with a follow-up examination at 1 year. Surgery was performed subsequently for all of the malignancy cases. Results: The average ages and mean tumor sizes for patients undergoing IUGE or DVAB were 46 and 47 years and 1.1 and 1.0 cm, respectively. The average IUGE and DVAB surgery durations for 88 benign tumors and 117 benign lesions were 44.3 and 21.5 minutes, respectively (P < 0.001), and 43.5 and 20.6 minutes for the malignant tumors (n = 16 and n = 11), respectively (P = 0.036). The IUGE and DVAB surgery durations for tumors <1 cm in diameter were 43.5 and 20.6 minutes, respectively, and 44.2 and 23.6 minutes for tumors over that size (P < 0.001). An older-model mammotome was used for 75 patients, with an average duration of 24 minutes in comparison to 18 minutes for the handheld variant (P < 0.001). No false-negative results were noted and, except in the case of the malignant tumors, there was no need for reexcisional biopsy. Further, there were no underestimates of the disease for the 4 cases of atypical ductal hyperplasia and the 12 of noninvasive carcinoma. No further ultrasonographic evidence of tumors was noted for 95% of the benign pathologies, with no residual abnormality detected for 13 of the 27 malignant tumors after IUGE or DVAB. Conclusions: For treatment of nonpalpable breast lesions, both IUGE and DVAB eliminate false-negative results, underestimates, and the requirement for reexcisional biopsies. In comparison to IUGE, DVAB is more convenient and time efficient for excisional biopsy of nonpalpable breast lesions.


Ultrasound in Obstetrics & Gynecology | 2004

Analysis of sonographic features for the differentiation of benign and malignant breast tumors of different sizes.

Szu-Tah Chen; Yun-Chung Cheung; C.-H. Su; M. F. Chen; T. L. Hwang; S. Hsueh

To analyze the value of various sonographic features in differentiating benign from malignant breast tumors of different sizes to improve the diagnostic accuracy in small lesions.


Lung Cancer | 2010

Adequacy and complications of computed tomography-guided core needle biopsy on non-small cell lung cancers for epidermal growth factor receptor mutations demonstration: 18-gauge or 20-gauge biopsy needle

Yun-Chung Cheung; John Wen-Cheng Chang; Jia-Juan Hsieh; Gigin Lin; Ying-Huang Tsai

INTRODUCTION To compare adequacy of tissue acquisition for EGFR DNA mutation analysis and the resulting complications in CT-guided lung biopsy cases with either 18-gauge or 20-gauge core biopsy needle. METHODS Forty-seven patients with advanced staged non-small cell lung cancers who were failure-treated by conventional chemotherapy were retrospectively reviewed. All had received CT-guided core needle lung biopsy for histology diagnosis and freshly frozen for EGFR mutation analysis before targeted therapy. We compared the complications resulting from these CT-guided lung biopsies and the specimen assessment using 18-gauge (32 patients) or 20-gauge (15 patients) biopsy needle via 17-gauge or 19-gauge coaxial needle. RESULTS With an overall pneumothorax rate of 12.8%, pneumothorax occurred in 12.5% and 13.3% of patients by 17-gauge and 19-gauge coaxial needles respectively. The overall rate of hemoptysis was 6.4%, with 6.3% by 18-gauge biopsy needle and 6.6% by 20-gauge biopsy needle. Large peritumoral hemorrhage revealed only in 2 cases of those completed with 18-gauge biopsy needles. 18-gauge biopsy needle obtained larger specimens with heavier weight (average 10.15mg vs 9mg) and higher DNA concentration (average 47.13ng/ul vs 35.92ng/ul) than 20-gauge biopsy needle. Otherwise, the range of optical density (1.67-2.09) was more constant in the specimens by 20-gauge biopsy needles. Mutation demonstration was achieved for all samples. CONCLUSION CT-guided core needle biopsy is a feasible technique in acquisition of fresh cancer tissues for EGFR gene mutation analysis. The specimen is adequate for gene demonstration either using 18-gauge or 20-gauge tru-cut biopsy needles via 17-gauge or 19-gauge coaxial needles.


Journal of The Formosan Medical Association | 2007

CT-guided hook wire localization of subpleural lung lesions for video-assisted thoracoscopic surgery (VATS).

Yu-Ruei Chen; Kee-Min Yeow; Jui-Ying Lee; I-Hao Su; Sung-Yu Chu; Chih-Hui Lee; Yun-Chung Cheung; Hui-Ping Liu

BACKGROUND/PURPOSE Histologic diagnosis of suspicious small subpleural lung lesions is difficult and often impossible using existing image-guided needle biopsy techniques including video-assisted thoracoscopic wedge resection. Preoperative lung lesion localization provides a more obvious target to facilitate intraoperative resection. This study reviewed the indications, results and complications of CT-guided hook wire localization for subpleural lung lesions in video-assisted thoracoscopic surgery (VATS). METHODS Between February 2001 and January 2007, 41 patients (20 males, 21 females; mean age, 52.5 +/- 5.1 years) with 43 subpleural pulmonary lesions underwent preoperative CT-guided double-thorn hook wire localization prior to video-assisted thoracoscopic wedge resection. Nodule diameters ranged from 2 mm to 26 mm (mean, 9.7 +/- 1.6 mm). The distance of the lung lesions from the nearest pleural surfaces ranged from 2 mm to 30 mm (mean, 9.6 +/- 2.0 mm). Patients then received VATS within 5 hours. The efficacy of preoperative localization was evaluated in terms of procedure time, VATS success rate and associated complications of localization. RESULTS Forty-three wedge resections of the lungs containing 43 subpleural lung lesions as guided or assisted by the inserted hook wires were successfully performed in 41 VATS procedures (41 of 43 procedures, 95.3%). The mean procedure time for preoperative CT-guided hook wire localization was 30.4 +/- 2.8 minutes. Eight patients had asymptomatic minimal pneumothoraces (18.6%); six patients had minimal needle tract parenchymal hemorrhages (13.9%) and one patient (2.3%) had an estimated 100 mL of hemothorax due to a small intercostal artery bleed that was cauterized during operation. The mean procedure time for VATS was 103 +/- 9.7 minutes (range, 44-198 minutes). Pathologic examination revealed seven primary lung cancers, 11 metastases, one hemangioma, 19 definite non-neoplastic pathologies, two nonspecific chronic inflammation, and three metallic foreign bodies. Diagnostic yield was 95%. No major complications related to the preoperative hook wire localization and VATS were noted. CONCLUSION CT-guided hook wire fixation is useful, helps in precise lesion localization in VATS wedge resection, and has a low rate of minor complications.


Acta Radiologica | 2008

Computed Tomography-Guided Core-Needle Biopsy Specimens Demonstrate Epidermal Growth Factor Receptor Mutations in Patients with Non-Small-Cell Lung Cancer

C.-M. Chen; John Wen-Cheng Chang; Yun-Chung Cheung; Gigin Lin; Jia-Juan Hsieh; Todd Hsu; Shiu-Feng Huang

Background: Target therapy with a new class of epidermal growth factor receptor (EGFR) inhibitors shows improved clinical response in EGFR gene-mutated lung cancers. Purpose: To evaluate the use of computed tomography (CT)-guided core-needle biopsy specimens for the assessment of EGFR gene mutation in non-small-cell lung cancer (NSCLC). Material and Methods: Seventeen (nine males, eight females) patients with advanced NSCLC were enrolled in this study. All patients underwent CT-guided core-needle biopsy of the lung tumor prior to treatment with the EGFR inhibitor gefitinib. There were no life-threatening complications of biopsy. The specimens were sent fresh-frozen for EGFR mutation analysis and histopathological study. Results: There were 12 (70.6%) EGFR gene mutants and five (29.4%) nonmutants. The objective response rate to gefitinib therapy was 73.3% (11 of 15 patients), with 91.7% (11 of 12 mutants) for the mutant group and 0% for the nonmutant group. Conclusion: CT-guided core-needle biopsy of advanced NSCLC enables the acquisition of sufficient tissue for EGFR gene mutation analysis.


Annals of Surgical Oncology | 2006

Prognosis of Breast Cancer After Supraclavicular Lymph Node Metastasis: Not a Distant Metastasis

Shin-Cheh Chen; Hsien-Kun Chang; Yung-Chang Lin; Wai-Man Leung; Chien-Sheng Tsai; Yun-Chung Cheung; Swei Hsueh; Lai-Chu See; Miin-Fu Chen

BackgroundWe performed this study to analyze the survival of breast cancer patients with isolated supraclavicular lymph node metastasis (SLNM) and assess whether SLNM is distant metastasis or not.MethodsSixty-three patients who developed an isolated SLNM among 3170 primary breast cancer patients between 1990 and 1999 were enrolled. The survival after SLNM was compared with that of 151 patients who developed local recurrences and 599 who had distant metastasis and was analyzed according to different levels and numbers of positive axillary nodes.ResultsThirty-five of the 63 patients died during a median follow-up of 58.3 months. The 5-year overall survival (OS) rates after SLNM, local relapse, and distant metastasis were 33.6%, 34.9%, and 9.1%, respectively. The 5-year OS for patients with involved nodes confined to axillary level I was 74.4%, which was significantly better than that for involved nodes in level II or III or SLNM (49.2%, 52.8%, and 33.6%, respectively; P < .0001). For one to three positive axillary nodes, the 5-year OS was 83.2%, which was significantly better than that for four to nine positive nodes, more than nine positive nodes, and SLNM (62.6%, 42.3%, and 33.6%, respectively). There was no significant difference between SLNM and more than nine positive nodes. Surgical removal of the supraclavicular nodes was a significantly better prognostic factor for OS after SLNM (P = .0327).ConclusionsThe 5-year OS after supraclavicular nodal metastosis, local relapse, and distant metastasis were 33.6%, 34.9%, and 9.1%, respectively. Good neck control either by surgery or chemotherapy achieved better survival.


Journal of Clinical Ultrasound | 2000

Sonographically guided core-needle biopsy in the diagnosis of superficial lymphadenopathy.

Yun-Chung Cheung; Yung-Liang Wan; Kar-Wai Lui; Kam-Fai Lee

This study was designed to evaluate the efficacy of ultrasound‐guided percutaneous core‐needle biopsy for establishing histopathologic diagnoses of palpable enlarged lymph nodes.

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Yung-Feng Lo

Memorial Hospital of South Bend

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Siu-Cheung Chan

Memorial Hospital of South Bend

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Ho-Fai Wong

Memorial Hospital of South Bend

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Kar-Wai Lui

Memorial Hospital of South Bend

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Shin-Cheh Chen

Memorial Hospital of South Bend

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