Eisuke Matsui

Screening for Lung Cancer With Low-Dose Helical Computed Tomography: Anti-Lung Cancer Association Project

PURPOSE Because efficacy of lung cancer screening using chest x-ray is controversial and insufficient, other screening modalities need to be developed. To provide data on screening performance of low-dose helical computed tomography (CT) scanning and its efficacy in terms of survival, a one-arm longitudinal screening project was conducted. PATIENTS AND METHODS A total of 1,611 asymptomatic patients aged 40 to 79 years, 86% with smoking history, were screened by low-dose helical CT scan, chest x-ray, and 3-day pooled sputum cytology with a 6-month interval. RESULTS At initial screening, the proportions of positive tests were 11.5%, 3.4%, and 0.8% with low-dose helical CT scan, chest x-ray, and sputum cytology, respectively. In 1,611 participants, 14 (0.87%) cases of lung cancer were detected, with 71% being stage IA disease and a mean tumor diameter of 19.8 mm. At repeated screening, the proportions of positive tests were 9.1%, 2.6%, and 0.7% with low-dose helical CT, chest x-ray, and sputum cytology, respectively. In 7,891 examinations, 22 (0.28%) cases of lung cancer were detected, with 82% being stage IA disease and a mean tumor diameter of 14.6 mm. The 5-year survival rate for screen-detected lung cancer was 76.2% and 64.9% for initial and repeated screening, respectively. CONCLUSION Screening with low-dose helical CT has potential to improve screening efficacy in terms of reducing lung cancer mortality. An evaluation of efficacy using appropriate methods is urgently required.

Progression of focal pure ground-glass opacity detected by low-dose helical computed tomography screening for lung cancer.

Objective: To clarify the progression of focal pure ground-glass opacity (pGGO) detected by low-dose helical computed tomography (CT) screening for lung cancer. Methods: A total of 15,938 low-dose helical CT examinations were performed in 2052 participants in the screening project, and 1566 of them were judged to have yielded abnormal findings requiring further examination. Patients with peripheral nodules exhibiting pGGO at the time of the first thin-section CT examination and confirmed histologically by thin-section CT after follow-up of more than 6 months were enrolled in the current study. Progression was classified based on the follow-up thin-section CT findings. Results: The progression of the 8 cases was classified into 3 types: increasing size (n = 5: bronchioloalveolar carcinoma [BAC]), decreasing size and the appearance of a solid component (n = 2: BAC, n = 1; adenocarcinoma with mixed subtype [Ad], n = 1), and stable size and increasing density (n = 1: BAC). In addition, the decreasing size group was further divided into 2 subtypes: a rapid-decreasing type (Ad: n = 1) and a slow-decreasing type (BAC: n = 1). The mean period between the first thin-section CT and surgery was 18 months (range: 7–38 months). All but one of the follow-up cases of lung cancer were noninvasive whereas the remaining GGO with a solid component was minimally invasive. Conclusions: The pGGOs of lung cancer nodules do not only increase in size or density, but may also decrease rapidly or slowly with the appearance of solid components. Close follow-up until the appearance of a solid component may be a valid option for the management of pGGO.

Prediction of Pulmonary Function After Resection of Primary Lung Cancer: Utility of Inhalation-perfusion Spect Imaging

To help determine whether preoperative perfusion and inhalation SPECT imagings are useful in predicting postoperative lung function, Tc-99m MAA perfusion SPECT imaging, CT scans, and pulmonary function tests were prospectively performed in 33 patients with primary lung cancer before and after lobectomy or pneumonectomy. Tc-99m Technegas inhalation SPECT imaging was performed in 6 of 33 patients as well. The authors also studied changes in radioactivity on the operated and nonoperated sides before and after surgery, examined the lowest limit value for adaptability to the operation, and made a comparison of both perfusion and inhalation SPECT imaging. The predicted postoperative values obtained from the preoperative Tc-99m MAA SPECT images correlated more closely with the measured 6-month postoperative values than with the measured 3-month postoperative values. The highest correlation coefficient (r = 0.86) was observed between the predicted forced vital capacity (FVC) value and the measured 6-month postoperative FVC value. In many cases, there was not a great difference between the 6-month and 3-month radioactivity on the operated side obtained from Tc-99m MAA SPECT images. This appears to indicate that pulmonary blood flow on the operated side has completely recovered by 3 months after surgery. However, radioactivity in both the upper and lower lobes of the nonoperated side increased soon after surgery compared with that before the operation, and had not returned to preoperative levels 6 months after surgery. The radioactivity in the right middle lobe did not change before and after surgery. The lowest limit value for adaptability to the operation was estimated to be 1.1 L for FVC and 900 ml for forced expiratory volume (FEV)1.0. The predicted values obtained from both perfusion and inhalation SPECT studies closely approximated each other, making it difficult to determine which SPECT imaging was superior.

Multiple chondromatous hamartomas of the lung

Multiple chondromatous hamartomas of the lung, which are very rare, are a feature of Carney syndrome. The relation between the two entities is not clear.

The adenocarcinoma-specific stage shift in the Anti-lung Cancer Association project: Significance of repeated screening for lung cancer for more than 5 years with low-dose helical computed tomography in a high-risk cohort

BACKGROUND We investigated whether a stage shift occurs during long-term repeated screening for lung cancer with low-dose helical computed tomography (LDCT) in a high-risk cohort. METHODS A total of 2120 subjects (mean age, 63 years; 87% male and 83% smokers) were continuously recruited and underwent repeated screening with LDCT from 1993 through 2004. RESULTS Nineteen lung cancers were detected at baseline examinations (prevalence cancers), and 57 lung cancers were detected at subsequent examinations (incidence cancers). For both prevalence cancers and incidence cancers, adenocarcinoma (74% and 63%, respectively), especially invasive adenocarcinoma (42% and 23%, respectively), was the most common histological diagnosis, and stage IA was the most common pathological stage (58% and 79%, respectively). The detection rate of incidence cancers other than bronchioloalveolar carcinoma became significantly higher after 5 years of LDCT examinations (r=0.50, P=0.020). Moreover, both the percentage of cancers of stage II-IV and tumor size became significantly lower for invasive adenocarcinoma after 5 years of LDCT examinations (r=-0.77, P=0.007 and r=-0.60, P=0.029, respectively). CONCLUSIONS Repeated screening for more than 5 years might demonstrate the efficacy of LDCT screening for lung cancer through an adenocarcinoma-specific stage shift.

Rounded atelectasis: delineation of enfolded visceral pleura by MRI.

Rounded atelectasis is an uncommon but increasingly recognized benign form of peripheral lung collapse (1). A variety of terms have been suggested for the entity, including contracted pleurisy, folded lung, pleuroma, atelectatic pseudotumor, Blesovsky syndrome, and shrinking pleuritis with atelectasis (2). Rounded atelectasis appears as a mass-like lesion that often mimics a pulmonary neoplasm (3). We report a case of rounded atelectasis shown as a clear delineation of enfolded visceral pleura by contrast-enhanced dynamic T1-weighted imaging.

Visualization and quantitative analysis of lung microstructure using micro CT images

Micro CT system is developed for lung function analysis at a high resolution of the micrometer order (up to 5 μm in spatial resolution). This system reveals the lung distal structures such as interlobular septa, terminal bronchiole, respiratory bronchiole, alveolar duct, and alveolus. In order to visualize lung 3-D microstructures using micro CT images and to analyze them, this research presents a computerized approach. In this approach, the following things are performed: (1) extracting lung distal structures from micro CT images, (2) visualizing extracted lung microstructure in three dimensions, and (3) visualizing inside of lung distal area in three dimensions with fly-through. This approach is applied for to micro CT images of human lung tissue specimens that were obtained by surgical excision and were kept in the state of the inflated fixed lung. And this research succeeded in visualization of lung microstructures using micro CT images to reveal the lung distal structures from bronchiole up to alveolus.

Image analysis of pulmonary nodules using micro CT

We are developing a micro-computed tomography (micro CT) system for imaging pulmonary nodules. The purpose is to enhance the physician performance in accessing the micro- architecture of the nodule for classification between malignant and benign nodules. The basic components of the micro CT system consist of microfocus X-ray source, a specimen manipulator, and an image intensifier detector coupled to charge-coupled device (CCD) camera. 3D image reconstruction was performed by the slice. A standard fan- beam convolution and backprojection algorithm was used to reconstruct the center plane intersecting the X-ray source. The preprocessing of the 3D image reconstruction included the correction of the geometrical distortions and the shading artifact introduced by the image intensifier. The main advantage of the system is to obtain a high spatial resolution which ranges between b micrometers and 25 micrometers . In this work we report on preliminary studies performed with the micro CT for imaging resected tissues of normal and abnormal lung. Experimental results reveal micro architecture of lung tissues, such as alveolar wall, septal wall of pulmonary lobule, and bronchiole. From the results, the micro CT system is expected to have interesting potentials for high confidential differential diagnosis.

Extracting alveolar structure of human lung tissue specimens based on surface skeleton representation from 3D micro-CT images

We have developed a Micro CT system for understanding lung function at a high resolution of the micrometer order (up to 5µm in spatial resolution). Micro CT system enables the removal specimen of lungs to be observed at micro level, has expected a big contribution for micro internal organs morphology and the image diagnosis study. In this research, we develop system to visualize lung microstructures in three dimensions from micro CT images and analyze them. They characterize in that high CT value of the noise area is, and the difficulty of only using threshold processing to extract the alveolar wall of micro CT images. Thus, we are developing a method of extracting the alveolar wall with surface thinning algorithm. In this report, we propose the method which reduces the excessive degeneracy of figure which caused by surface thinning process. And, we apply this algorithm to the micro CT image of the actual pulmonary specimen. It is shown that the extraction of the alveolus wall becomes possible in the high precision.

Endobronchial Spread of Parenchymal Metastases

We are pleased that Drs. Golpe and Mateos found our article of interest and that they had similar findings in their smaller study. Their study confirms that transient minor desaturation is common during bronchoscopy, but we differ in our response to this finding. We are unaware of any reports of adverse consequences from transient minor desaturation of the type described in both articles. Therefore, any recommendation to administer oxygen to all patients during flexible bronchoscopy must be regarded as a non–evidence-based suggestion. Golpe and Mateos have also reported minor desaturation after the bronchoscopy procedure, and they suggest that oxygen treatment should be continued for an unspecified time after the procedure. This would increase the cost and complexity of running a bronchoscopy service (our present practice is to continue oxygen treatment after bronchoscopy only if oximetry indicates hypoxia following the procedure). The significance of transient mild desaturation (mean SD arterial oxygen saturation, 91 3%) during the recovery phase is of very uncertain significance. The patients had no instrumentation during this phase. For example, it is known that patients with moderate COPD but normal resting oxygen saturation can have significant hypoxia develop at an oxygen pressure equal to that of a commercial airliner, with a further fall to a mean saturation of 80% during mild exercise.1 These patients were all asymptomatic, and it has never been suggested that COPD patients with normal resting blood gas should be administered oxygen during flight. We are confident about the safety of our present practice of administering oxygen only to patients who have sustained hypoxia develop (or to those with high-risk features, such as angina).