Kyung-Min Shin

Locally advanced rectal cancer: post-chemoradiotherapy ADC histogram analysis for predicting a complete response

Background The value of diffusion-weighted imaging (DWI) for reliable differentiation between pathologic complete response (pCR) and residual tumor is still unclear. Recently, a few studies reported that histogram analysis can be helpful to monitor the therapeutic response in various cancer research. Purpose To investigate whether post-chemoradiotherapy (CRT) apparent diffusion coefficient (ADC) histogram analysis can be helpful to predict a pCR in locally advanced rectal cancer (LARC). Material and Methods Fifty patients who underwent preoperative CRT followed by surgery were enrolled in this retrospective study, non-pCR (n = 41) and pCR (n = 9), respectively. ADC histogram analysis encompassing the whole tumor was performed on two post-CRT ADC600 and ADC1000 (b factors 0, 600 vs. 0, 1000 s/mm2) maps. Mean, minimum, maximum, SD, mode, 10th, 25th, 50th, 75th, 90th percentile ADCs, skewness, and kurtosis were derived. Diagnostic performance for predicting pCR was evaluated and compared. Results On both maps, 10th and 25th ADCs showed better diagnostic performance than that using mean ADC. Tenth percentile ADCs revealed the best diagnostic performance on both ADC600 (AZ 0.841, sensitivity 100%, specificity 70.7%) and ADC1000 (AZ 0.821, sensitivity 77.8%, specificity 87.8%) maps. In comparison between 10th percentile and mean ADC, the specificity was significantly improved on both ADC600 (70.7% vs. 53.7%; P = 0.031) and ADC1000 (87.8% vs. 73.2%; P = 0.039) maps. Conclusion Post-CRT ADC histogram analysis is helpful for predicting pCR in LARC, especially, in improving the specificity, compared with mean ADC.

Prognostic implications of computed tomographic right ventricular dilation in patients with acute pulmonary embolism

INTRODUCTION Whether right ventricular (RV) dilation on computerized tomography (RVD-CT) is a useful predictor for clinical outcomes of acute pulmonary embolism (PE) remains debatable. Furthermore, data regarding the best combination of prognostic markers for predicting the adverse outcome of PE are limited. MATERIALS AND METHODS The authors retrospectively reviewed 657 consecutive patients hospitalized at a tertiary referral center with a diagnosis of PE based on multi-detector row CT scan. RESULTS Patients were allocated into an adverse outcome group (11% [n = 69]) or a low risk group (89% [n = 588]). Multivariate analysis showed that RVD-CT (RV/left ventricle [LV] diameter ratio ≥ 1), high pulmonary embolism severity index (PESI) score (class IV-V), high N-terminal-pro-B-type natriuretic peptide (NT-proBNP,≥ 1,136 pg/ml), and elevated troponin I (≥ 0.05 ng/ml) significantly predicted an adverse outcome (odds ratio [OR] 6.26, 95% confidence interval [CI] 2.74-14.31, p < 0.001; OR 4.71, 95% CI 2.00-11.07, p < 0.001; OR 2.71, 95% CI 1.15-6.39, p = 0.023; and OR 3.00, 95% CI 1.27-7.07, p = 0.012, respectively). The addition of RVD-CT to PESI, NT-proBNP, troponin I or their combinations enhanced the positive predictive values and positive likelihood ratios of an adverse outcome. CONCLUSIONS RVD-CT could be an independent prognostic factor of adverse outcomes in patients with acute PE, and provides additional prognostic value when combined with other prognostic factors.

Prevalence and predictors of pulmonary embolism in Korean patients with exacerbation of chronic obstructive pulmonary disease.

Background: Data concerning the rate of pulmonary embolism (PE) in Asian patients with chronic obstructive pulmonary disease (COPD) exacerbation are sparse, and no study has shown predictors of PE in these patients. Objectives: The purpose of the present study was to investigate the prevalence and predictors of PE in Korean patients with COPD exacerbation. Methods: Hospitalized patients with COPD exacerbations were prospectively enrolled into this study and underwent computed tomography (CT) pulmonary angiography and indirect CT venography. Results: The most common cause of COPD exacerbation was lower respiratory tract infection (82%; n = 84), followed by PE (5%; n = 5). Eight patients (8%) had venous thromboembolism, and deep vein thrombosis (DVT) was seen in 6%, with proximal DVT in 4%. On multivariate analysis, the absence of symptoms of respiratory infection and plasma D-dimer elevation (≥500 µg/l) were significant factors predicting PE in patients with COPD exacerbations (odds ratio 31, 95% confidence interval 2-563, p = 0.02, and odds ratio 25, 95% confidence interval 1-464, p = 0.03, respectively). Conclusions: PE comprises approximately 5% of the etiologies of COPD exacerbations in Koreans. The absence of symptoms suggestive of respiratory infection and elevated plasma D-dimer levels were significant predictors of PE in this population.

Clinical Characteristics of Patients with Peripheral Pulmonary Embolism

Background: The clinical relevance of emboli limited to the segmental or sub-segmental pulmonary arteries and the role of anticoagulation in patients with these conditions remains to be clarified. Objectives: To determine the clinical characteristics and treatment outcomes of peripheral pulmonary embolism (PE), and in particular, isolated sub-segmental PE (ISSPE). Methods: We reviewed the data for 334 patients who were diagnosed with a PE by computed tomographic (CT) pulmonary angiography and indirect CT venography. Results: All patients were classified into one of three groups: central (245 patients, 73.4%); segmental (67 patients, 20.1%), and sub-segmental (22 patients, 6.6%). An incidental CT finding (63.6%) was the most common presentation in the segmental and sub-segmental groups. Compared with the central group, the sub-segmental group had less frequent proximal deep venous thrombosis (14 vs. 47%, Bonferroni’s corrected p = 0.002), and greater preservation of oxygenation levels (p < 0.05) without hemodynamic instability. The recurrence of PE and deaths related to PE did not occur in the sub-segmental group, although approximately 30% of the patients did not receive anticoagulation therapy. Conclusions: Patients with ISSPE may have a more benign clinical presentation, as compared to the central type, and may follow a good clinical course without mortality or recurrence.

Clinical relevance and characteristics of pleural effusion in patients with Mycoplasma pneumoniae pneumonia

Abstract Data regarding parapneumonic pleural effusion in Mycoplasma pneumoniae pneumonia (MP) patients are limited. In this study MP patients with pleural effusion tended to be younger and had longer hospital stays and more common use of systemic steroids compared to those without pleural effusion. In 5 of the 6 patients for whom pleural fluid data were available, the pleural effusion was lymphocyte-predominant rather than polymorphonuclear leukocyte-predominant; these patients also had elevated adenosine deaminase levels. Taken together, these results indicate that MP patients with pleural effusion may have a more severe form compared to those without pleural effusion. M. pneumoniae should be considered an aetiological agent of lymphocyte-predominant pleural effusion.

Central emboli rather than saddle emboli predict adverse outcomes in patients with acute pulmonary embolism

INTRODUCTION In patients with acute pulmonary embolism (PE), the prognostic implications of saddle or central emboli, as observed on computed tomography (CT), remain to be established. The aim of the present study was to assess whether the presence of saddle and central emboli could be used to predict clinical outcomes in patients with PE. MATERIALS AND METHODS The authors retrospectively reviewed 743 consecutive patients hospitalized at a tertiary referral center with a diagnosis of PE based on multi-detector row CT scan. RESULTS All the clinical variables did not differ between saddle emboli (5.8% [n = 43]) and right or left pulmonary artery emboli (29.7% [n = 221]), and the frequency of an adverse outcome was not significantly different between the two groups. Saddle emboli and right or left pulmonary artery emboli were grouped into central emboli (35.5% [n = 264]). Patients were allocated to an adverse outcome group (10.5% [n = 78]) or a control group (89.5% [n = 665]). Multivariate analysis demonstrated that PE severity index (PESI) score (class IV-V), N-terminal-pro-B-type natriuretic peptide level (≥ 1,406 pg/mL), right ventricular dilation on CT (right ventricle/left ventricle diameter ratio ≥ 1), and central emboli significantly predicted an adverse outcome. The addition of central emboli to other established prognostic factors such as PESI enhanced the positive predictive values and positive likelihood ratios of an adverse outcome for acute PE. CONCLUSIONS Rather than saddle emboli, central emboli could be an independent prognostic factor of adverse outcomes in patients with acute PE and provide additional prognostic value when combined with other prognostic factors.

Focal necrotizing pneumonia is a distinct entity from lung abscess

‘Focal necrotizing pneumonia’ was defined as a localized type of necrotizing pneumonia characterized by a single or few cavities of low density without rim enhancement on computed tomography (CT) scan. The purpose of this study was to investigate the clinical features and course of patients with focal necrotizing pneumonia, thereby elucidating its clinical relevance.

Clinical relevance of pulmonary infarction in patients with pulmonary embolism

INTRODUCTION Data regarding the clinical relevance of pulmonary infarction (PI) in patients with pulmonary embolism (PE) are lacking. The aim of this study was to investigate the clinical features of PE patients with PI and the prognostic role of PI for PE patients. MATERIALS AND METHODS Based on computed tomography scan, 509 patients with PE were divided into two groups, the infarction group (n=45) and the non-infarction group (n=464). A variety of clinical parameters were compared between the two groups. RESULTS In the infarction group, the largest pulmonary arteries involved by emboli were central rather than peripheral and more proximal as compared to the non-infarction group (p=0.01 and p<0.03, respectively). Thrombolytic agents tended to be more frequently administered in the infarction group (13.3% [n=6] versus 6.3% [n=29], p=0.07). In-hospital mortality, PE-related deaths, and the recurrence rate of PE did not differ between the two groups. CONCLUSIONS The present study did not demonstrate that PI is a prognostic indicator of recurrence and mortality in PE patients. We suggest the possibility that blood clot burden is greater in PE patients with PI, although PI by itself occurs in small pulmonary arteries.

Bacterial pneumonia following cytotoxic chemotherapy for lung cancer: clinical features, treatment outcome and prognostic factors.

Abstract Data regarding treatment outcomes and prognosis in pneumonia that occurs after lung cancer chemotherapy are lacking. We performed a retrospective study of 84 patients with clinically suspected bacterial pneumonia after cytotoxic chemotherapy for lung cancer. Small cell carcinoma was the most common histological type (36.9%, n = 31), followed by squamous cell carcinoma (35.7%, n = 30) and adenocarcinoma (21.4%, n = 18). The most frequent pathogen was Streptococcus pneumoniae (n = 14), followed by Klebsiella pneumoniae (n = 10), Staphylococcus aureus (n = 8), and Pseudomonas aeruginosa (n = 7). Of 84 patients, treatment outcome was determined for 80; the outcome was success in 52 (61.9%) and failure in 28 (33.3%); outcome remained undetermined for 4 patients (4.8%). Based on multivariate analysis, tachypnoea (respiratory rate ≥20/min) was the only significant predictor of treatment failure (odds ratio 4.79, 95% confidence interval 1.17–19.70; p = 0.030). In conclusion, bacterial pneumonia after cytotoxic chemotherapy for lung cancer was found to be caused more often by S. pneumoniae and K. pneumoniae than P. aeruginosa, and treatment failure leading to death was found to be high. Tachypnoea was independently associated with treatment failure in this population.

Mycoplasma pneumoniae bronchiolitis in adults: Clinicoradiologic features and clinical course

The clinicoradiologic features of Mycoplasma pneumoniae bronchiolitis in adults remain unclear. 29 patients with M. pneumoniae infection were collected and classified by computed tomographic findings (bronchiolitis (n=8) and pneumonia (n=21)). M. pneumoniae bronchiolitis is not rare in adults and is clinically similar to M. pneumoniae pneumonia, despite radiographic differences.