Byungjoon Park

Prediction of Pathologic Grade and Prognosis in Mucoepidermoid Carcinoma of the Lung Using 18F-FDG PET/CT

Objective The maximum standardized uptake value (SUVmax) of pulmonary mucoepidermoid carcinoma (PMEC) in fluorine-18fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) was evaluated as a preoperative predictor of pathologic grade and survival rate. Materials and Methods Twenty-three patients who underwent preoperative PET/CT and complete resection for PMEC were enrolled. The optimal cut-off SUVmax for tumor grade was calculated as 6.5 by receiver operating characteristic curve. The patients were divided into a high SUV group (n = 7) and a low SUV group (n = 16). Clinicopathologic features were compared between the groups by χ2 test and overall survival was determined by Kaplan-Meier analysis. Results The mean SUVmax was 15.4 ± 11.5 in the high SUV group and 3.9 ± 1.3 in the low SUV group. All patients except one from the low SUV group had low grade tumors and all had no nodal metastasis. The sensitivity and specificity of SUVmax from PET/CT for predicting tumor grade was 85.7% and 93.8%, respectively. During the follow-up period (mean, 48.6 ± 38.7 months), four patients from the high SUV group experienced cancer recurrence, and one died of cancer. In contrast, none of the low SUV group had recurrence or mortality. Five-year overall survival rate was significantly higher in the low SUV group (100% vs. 71.4%, p = 0.031). Conclusion Pulmonary mucoepidermoid carcinoma patients with high SUVmax in PET/CT had higher tumor grade, more frequent lymph node metastasis and worse long-term outcome. Therefore, PMEC patients with high uptake on PET/CT imaging might require aggressive mediastinal lymph node dissection and adjuvant therapies.

Transaortic chordae and pannus removal without redo mitral valve replacement in prosthetic mitral valve malfunction.

Both anterior and posterior chordae of the mitral valve are occasionally spared during mitral valve surgery to preserve left ventricular function. In this report, a 43-year-old woman who had undergone mitral valve replacement surgery with anterior and posterior chordal preservation 9 years ago subsequently had mitral valve pannus and anterior chordae covering the prosthetic valve, which led to valve malfunction. Prosthetic mitral valve function was successfully recovered by performing transaortic pannus and chordae removal, avoiding redo mitral valve replacement.

Automatic current control of magnet cranes for steel plate yard automation

Abstract This paper presents an automatic current-control method for magnet cranes for thick steel plate yard automation. In moving the steel plates from stack to stack or from stack to shipping truck, it is difficult to lift the correct number of steel plates because the dimensions of the stacked steel plates are in general different, and their other parameters are not completely known and may even vary in a nonlinear fashion. In this paper, recursive form flux equations are first derived for the thick steel plates, and a current equation is then determined for the magnet coil. Based on these equations, an adaptive current predictor is developed to exert the right amount of current on the magnet, so as to lift the correct number of steel plates. When the initial trial with this current fails, a current tuning method is introduced to adjust the current and lift the correct number of plates. The developed magnet current controller has been successfully tested on data obtained from the storage yard at the Pohang Iron & Steel Co. (POSCO).

Pneumonectomy for Clinical Stage I Non-Small Cell Lung Cancer in Elderly Patients over 70 Years of Age.

Background Lobectomy is the generally accepted standard treatment for early-stage non-small cell lung cancer (NSCLC). However, especially in elderly patients, it is often necessary to perform pneumonectomy in order to maximize the likelihood of curative treatment, although pneumonectomy is a challenging procedure. Methods We analysed patients who were clinically diagnosed with stage I NSCLC and underwent pneumonectomy with curative intent from 2004 to 2011. The patients were divided into an elderly group (≥70 years) and a younger group (<70 years). We retrospectively analysed the outcomes of these groups of patients in order to characterize the role of pneumonectomy as a treatment for elderly patients with clinical stage I NSCLC. Results Thirty patients younger than 70 years of age (younger group) and fourteen patients 70 years of age or older (elderly group) who underwent pneumonectomy were enrolled in the present study. The median follow-up period was 35 months (range, 0 to 125 months). The perioperative mortality rate (within 90 days after the operation) was 7.1% in the elderly group and 6.7% in the younger group (p=0.73). No significant differences between the two groups were observed regarding the occurrence of pneumonia, acute respiratory distress syndrome, cardiac arrhythmia, bronchopleural fistula, and vocal cord paralysis. The overall five-year survival rate was 79.4% in the younger group and 35.7% in the elderly group, which was a significant difference (p=0.018). The five-year disease-free survival rate was 66.7% in the younger group and 35.7% in the elderly group, but this difference was not statistically significant (p=0.23). Conclusion Although elderly patients with early stage lung cancer showed a worse long-term survival rate after pneumonectomy than younger patients, the outcomes of elderly patients were similar to those of younger patients in terms of perioperative mortality and postoperative complications. Patients should not be denied pneumonectomy solely due to old age.

An abnormal chord inserting to a subaortic membrane in hypertrophic cardiomyopathy: rare anatomical combination

Figure 1: A rod-like shadow (circle) in the left ventricular outflow tract of a 45-year-old female hypertrophic cardiomyopathy patient on echocardiogram (A) and cardiac magnetic resonance imaging (B). Mildly thickened subaortic membrane (C, Video 1). A thickened chorda, originating from the abnormal head of the anterolateral papillary muscle inserting to the subaortic membrane (D, Video 1). Specimens (E).

Clinical Implication of Transaortic Mitral Pannus Removal During Repeat Cardiac Surgery for Patients With Mechanical Mitral Valve

BACKGROUND This study aimed to evaluate the safety and feasibility of transaortic mitral pannus removal (TMPR).Methods and Results:Between 2004 and 2016, 34 patients (median age, 57 years; 30 women) with rheumatic disease underwent pannus removal on the ventricular side of a mechanical mitral valve through the aortic valve during reoperation. The median time interval from the previous surgery was 14 years. TMPR was performed after removal of the mechanical aortic valve (n=21) or diseased native aortic valve (n=11). TMPR was performed in 2 patients through a normal aortic valve. The mitral transprosthetic mean pressure gradient (TMPG) was ≥5 mmHg in 11 patients, including 3 with prosthetic valve malfunction. Prophylactic TMPR was performed in 23 patients. There were no early deaths. Concomitant operations included 22 tricuspid valve surgeries (13 replacements, 15 repairs) and 32 aortic valve replacements (24 repeats, 8 primary). The mean gradient in patients who had mitral TMPG ≥5 mmHg was significantly decreased from 6.46±1.1 to 4.37±1.17 mmHg at discharge (P<0.001). No mechanical valve malfunction was apparent on last echocardiography. CONCLUSIONS TMPR is a safe and effective procedure for patients with malfunction or stenosis of a mechanical mitral valve and may be considered an alternative approach in patients with pannus overgrowth in such valves.

Surgical management of locoregionally recurrent thymoma

Objectives:  There is no standard treatment for recurrent thymoma, but treatment is usually palliative therapy. For this article, we retrospectively reviewed our experiences to examine the efficacy of surgical treatment and the extent of adequate resection.