Biomedical subjects
Yeun-Chung Chang
Publications and source records attributed to Yeun-Chung Chang.
Dysphagia in patients with nasopharyngeal cancer after radiation therapy: a videofluoroscopic swallowing study.
This study evaluated swallowing status and the factors influencing swallowing in patients with nasopharyngeal carcinoma (NPC) after radiation therapy. During the period from July 1995 to June 1999, this cross-sectional study used videofluoroscopic swallowing study (VFSS) to evaluate 184 NPC patients who had completed radiation therapy [113 cases had completed radiation therapy < or = 12 months prior to evaluation (acute group) and 71 cases had completed radiation therapy > 12 months prior to evaluation (chronic group)]. The numbers of patients with tumors in each of the four stages were as follows: 24 in stage I, 45 in stage II, 41 in stage III, and 74 in stage IV. Swallowing abnormalities of the acute and chronic groups were correlated with multiple variables, including gender, age, the stage of the tumor, use of either neoadjuvant chemotherapy or radiosensitizer, and radiation modality. The analytical results indicated that the chronic group had a significantly higher proportion of swallowing abnormalities. Radiation modality, chemotherapy, and tumor staging were not significantly associated with swallowing dysfunction. Trend analysis revealed a progressive deterioration of most parameters of swallowing function in this group of patients. These findings indicate that swallowing function continues to deteriorate over time, even many years after radiation therapy in patients with NPC. Our results indicate that the time elapsed since radiation therapy correlates with the severity of dysphagia in NPC patients.
Usefulness of computed tomography-guided transthoracic small-bore coaxial core biopsy in the presence of a pneumothorax.
Transthoracic needle biopsy (TNB) is usually avoided in the presence of pneumothorax. The authors performed computed tomography (CT)-guided transthoracic core biopsy in the presence of pneumothorax in 13 patients (4.9%) selected from 265 patients who received CT-guided TNB over 4 years. These iatrogenic pneumothoraces were induced by previous ultrasound (US)-guided TNB (n = 5), transbronchial lung biopsy (n = 4), and CT-guided biopsy (n = 4). The time interval between previous thoracic intervention and CT-guided TNB ranged from 0 hours to 9 days after transbronchial lung biopsy (average, 4 days). A diagnostic core biopsy was performed in 12 of the 13 patients. Seven lesions proved to be malignant and five were benign. Failure of CT-guided transthoracic core biopsy occurred in a single patient with a previous US-guided biopsy within 24 hours. This patients demonstrated a progressively enlarging pneumothorax and was treated with air aspiration with CT guidance. A successful second biopsy was performed 7 days later after full expansion of the lung. There were no complications related to the procedures. The authors' experience suggests that CT-guided transthoracic core biopsy using small-bore coaxial technique can be safely performed with high-diagnostic yield in patients with stable iatrogenic pneumothorax.
Mature mediastinal teratoma: sonographic imaging patterns and pathologic correlation.
OBJECTIVE: To characterize the sonographic patterns of teratomas located within the mediastinum and to correlate them with pathologic findings, because there have been few reports concerning the application of sonography in the diagnosis of mediastinal teratoma. METHODS: Over a 9-year period, we carried out an image analysis of the sonographic findings of 28 mediastinal teratomas whose diagnoses were proved surgically. RESULTS: Sonography showed that 18 patients had a complex mass of heterogeneous echogenicity, including regional bright echoes (n = 12), acoustic shadows (n = 8), hyperechoic lines and dots (n = 7), soft tissue septa (n = 9), dermoid plugs (n = 6), and hypoechoic areas (n = 11). This type of mediastinal teratoma revealed, in pathologic findings, varying combinations of fat, sebaceous and mucinous materials, hair, mineralized elements, and multiple compartments. Eight patients had a homogeneous hyperechoic mass, and the 2 remaining patients had floating spherules within a cystic mass. Pathologically, the homogeneous mass mainly contained hair and sebaceous material. The floating spherules were also composed of sebaceous tissue and were above the fluid of the cyst. CONCLUSIONS: On the basis of the evaluation of the sonographic and pathologic findings, we described 3 major patterns of mediastinal teratoma: a complex mass of heterogeneous echogenicity, homogeneous high echogenicity within a solid mass, and floating spherules within a cystic mass. Thus, sonography can improve the diagnosis of mediastinal teratoma. However, additional prospective studies are needed to test the sensitivity and specificity of these sonographic patterns in the diagnosis of mediastinal teratoma.
Pedunculated hepatic hemangioma: report of two cases.
Pedunculated hepatic hemangioma may be confused with pedunculated hepatocellular carcinoma (HCC) in clinical practice because of their similar ultrasonographic pattern. We report two cases of asymptomatic pedunculated hepatic hemangioma. Both patients presented with intraabdominal masses of unknown nature measuring about 5 cm in diameter. Pedunculated HCC was suspected because of a pedicle and ultrasonographic pattern in both patients, positive hepatitis B surface antigen as a risk factor in one patient, and the high prevalence of HCC in Taiwan. Diagnosis was established by computerized tomography, magnetic resonance imaging, radionuclide scintigraphy, and angiography in both patients and confirmed by histopathology of the surgical specimen in one patient. Pedunculated hepatic hemangioma should be included in the differential diagnosis of a mass located in the upper abdomen.