Impact of sleep-related hypoventilation in patients with pleuroparenchymal fibroelastosis.

BACKGROUND: Pleuroparenchymal fibroelastosis (PPFE) is a rare fibrosing lung disease with a predilection for the upper lobe and its progression causes hypoventilation, resulting in hypercapnia. Even though the association between sleep-related hypoventilation (SRH) and chronic obstructive pulmonary disease was well documented, its impact in patients with PPFE was not evaluated. The aim of this study is to clarify the impact of SRH on prognosis in PPFE. METHODS: A retrospective review of the medical records of 52 patients with PPFE who underwent transcutaneous carbon dioxide monitoring during sleep was done. Patients were stratified into SRH (n = 28) and non-SRH (n = 24) groups based on American Academy of Sleep Medicine criteria. The impact of SRH on the prognosis of PPFE, as well as the clinical factors and comorbidities of PPFE associated with SRH, were evaluated. RESULTS: Forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), total lung capacity (TLC), and carbon monoxide diffusing capacity (DLco) in the SRH group were significantly lower than the non-SRH group (P < .01). Chronic pulmonary aspergillosis (CPA) was found at a higher rate in the SRH group (P = .02). The median survival time for SRH patients was 330 days, whereas roughly 80% of non-SRH patients were alive during the 3-year observation period (P < .01). Body mass index was a significant prognostic factor in PPFE patients with SRH (HR .78; 95% CI; .64-.94; P < .01). Home oxygen therapy (HOT) during the day and noninvasive positive pressure ventilation (NPPV) at night while sleeping tended to improve prognosis in the SRH group, as indicated by HR of .25 (P = .07). CONCLUSIONS: SRH may be a poor prognostic factor for PPFE. Additionally, SRH may modify susceptibility to Aspergillosis in patients with PPFE. HOT plus NPPV may improve the disease outcomes in patients with SRH.

Metastatic brain tumors from non-small cell lung cancer with EGFR mutations: distinguishing influence of exon 19 deletion on radiographic features.

INTRODUCTION: Miliary brain metastasis is a rarity and refers to the presence of numerous small tumors in a perivascular distribution without intraparenchymal invasion and focal edema. Although the presence of epidermal growth factor receptor (EGFR) mutation and good response to gefitinib have been reported in non-small cell lung cancer (NSCLC) patients with miliary brain metastases, the influence of the EGFR mutations on the radiographic features remains unclear. PATIENTS AND METHODS: All NSCLC patients with synchronous brain metastases detected at the time of a new diagnosis of NSCLC from March 2005 through May 2011 were divided according to EGFR mutation status. The number of brain tumors, size of the largest brain tumors, and size of peritumoral brain edema were compared among the groups. RESULTS: Fifty-seven patients who met the criteria were divided into three groups: wild-type EGFR group (31 patients), exon 19 deletion group (18 patients), and exon 21 point mutation group (8 patients). The exon 19 deletion group had more multiple and smaller brain tumors with smaller peritumoral brain edema than did the wild-type group (P = 0.024, P = 0.0016, and P = 0.0036, respectively). The exon 21 point mutation group showed no significant difference in any of the radiographic values when compared with the wild-type group. CONCLUSION: Our results indicate that NSCLC patients with the exon 19 deletion have such a peculiar pattern of brain metastases as multiple small metastases with small brain edema. This metastatic pattern may be similar to that of miliary brain metastases. Because it is unclear whether or not severe neurologic symptoms develop during their clinical courses like miliary brain metastases, regular evaluation with brain magnetic resonance imaging (MRI) should be considered, regardless of the presence of neurologic symptoms. Accumulation of knowledge about specific pattern of brain metastasis will help approach to "individual" management.

[Development of the method for the similarity detection of descriptions in radiology reports using structuring technology].

Radiologists often spend much time for re-reading some of the past free-text radiology reports and determining interval changes in the physical findings when creating a report for long term cases. The aim of this study was to propose the method to detect semantic similar descriptions in the free-text reports using the structuring method based on text-mining technology. In a previous study, we had developed the structuring method that can semantically analyze the free-text reports and convert them into the description unit consisting of five items: finding/diagnosis, modifier, region, regional modifier, and confidence. Our developed prototype system extracted similar descriptions from the free-text reports by calculating the similarity index between description units. We confirmed similar descriptions extracted by the system applied to free-text reports of cases which had more than one chest CT examination written in actual clinical situation. As a result, it became available to identify candidates of similar descriptions from free-text reports. In some cases regarding practical use, the similar descriptions could not be identified in the sentences which used paraphrasing or where the findings had status changes. A solution of identifying similarity in these cases was necessary to improve the method. With the presented method here, it is expected that interval changes in the findings can be visualized and applied it to support diagnosis.

Application of support vector machine classifiers to preoperative risk stratification with myocardial perfusion scintigraphy.

BACKGROUND: Myocardial perfusion single-photon emission computed tomography (SPECT) has been used for risk stratification before non-cardiac surgery. However, few authors have used mathematical models for evaluating the likelihood of perioperative cardiac events. METHODS AND RESULTS: This retrospective cohort study collected data of 1,351 patients referred for SPECT before non-cardiac surgery. We generated binary classifiers using support vector machine (SVM) and conventional linear models for predicting perioperative cardiac events. We used clinical and surgical risk, and SPECT findings as input data, and the occurrence of all and hard cardiac events as output data. The area under the receiver-operating characteristic curve (AUC) was calculated for assessing the prediction accuracy. The AUC values were 0.884 and 0.748 in the SVM and linear models, respectively in predicting all cardiac events with clinical and surgical risk, and SPECT variables. The values were 0.861 (SVM) and 0.677 (linear) when not using SPECT data as input. In hard events, the AUC values were 0.892 (SVM) and 0.864 (linear) with SPECT, and 0.867 (SVM) and 0.768 (linear) without SPECT. CONCLUSION: The SVM was superior to the linear model in risk stratification. We also found an incremental prognostic value of SPECT results over information about clinical and surgical risk.

Structuring of free-text diagnostic report.

PURPOSE: It is useful to convert free-text diagnostic reports into structured diagnostic reports by semantic analysis for the secondary investigation of their contents. In this study, we propose a system in which description units are automatically extracted to create structured text reports and we evaluated its usefulness. METHODS: We defined the rules to create description units and developed the system that can automatically extract these description units from free-text diagnostic reports. We applied this system to reports of cerebral perfusion scintigrams and obtained 5 dictionaries of description units, increasing the number of scintigrams from 100 to 500 in increments of 100. Each dictionary was used to analyze another 100 scintigrams. The results obtained using each dictionary were compared with the results of physicians' interpretation. RESULTS: The recall rate of this system to the physicians' interpretation increased when correlated with the number of scintigrams but with 300 cases was almost saturated at 85%. CONCLUSION: We propose a semantic analysis system and show its usefulness in the semantic evaluation of the reports of cerebral perfusion scintigrams.

Preoperative risk stratification with myocardial perfusion imaging in intermediate and low-risk non-cardiac surgery.

BACKGROUND: Perioperative cardiac risk in high risk surgery is often stratified with myocardial perfusion single-photon emission computed tomography (SPECT). However, little and no data are available about intermediate and low-risk surgery, respectively. METHODS AND RESULTS: A total of 1,220 consecutive patients underwent electrocardiography-gated dipyridamole stress SPECT to evaluate myocardial perfusion and cardiac function before intermediate or low risk non-cardiac surgery. Variables predictive of perioperative cardiac events were determined and the usefulness of combining pretest information and the incremental prognostic value of SPECT was estimated. The frequency of all cardiac events depended on clinical risk factors and type of surgical procedures. After sorting the patients with clinical risk factors and surgical risk, assessment of myocardial perfusion or cardiac function yielded significant risk stratification in intermediate, but not in low-risk surgery. Adding functional data to perfusion variables offered an incremental prognostic value for patients with an intermediate clinical risk and scheduled intermediate risk surgery. CONCLUSIONS: Integrating information about clinical risk factors, type of surgery, myocardial perfusion and cardiac function allows detailed preoperative risk stratification. Preoperative SPECT provides an incremental prognostic value in intermediate, but not in low-risk surgery.

[Brachytherapy for prostate cancer].

This review article aims to overview modern prostate brachytherapy in Japan. Permanent transperineal prostate brachytherapy with I-125 started in September, 2003 in Japan. Brachytherapy has several advantages: the dose is adapted precisely to the tumor shape and size, and the long-lived isotope gives a higher tumor dose with less damage to normal tissue; less-time consuming for patients and staff: long-term results comparable to surgery or external beam series in the USA; and quality of life after brachytherapy also appealing. These advantages have brought about increasing use in Japan as well. Patients with a high probability of organ-confined disease and a low-risk group are appropriately treated with brachytherapy. Brachytherapy candidates with a significant risk of extraprostatic extension should be treated with supplemental external beam radiation therapy. High-dose-rate (HDR) brachytherapy with Ir-192 has preceded seed implants in Japan. HDR has some theoretical advantages. Long-term results of brachytherapy in the USA are comparable with surgery or external beam irradiation so far. We should develop more sophisticated brachytherapy techniques in Japan.