Masayuki Haniuda

Results of three-year mass screening programme for lung cancer using mobile low-dose spiral computed tomography scanner

The aim of this study was to evaluate the usefulness of annual screening for lung cancer by low-dose computed tomography (CT) and the characteristics of identified lung cancers. Subjects consisted of 5483 general population aged 40–74 years, who received initial CT scans in 1996, followed by repeat annual scans for most subjects in 1997 and 1998, with a total of 13 786 scans taken during 1996–1998. Work-up examinations for patients with suspicious lesions were conducted using diagnostic CTs. The initial screening in 1996 detected suspicious nodules in 279 (5.1%) of 5483 subjects, and 22 (8%) were confirmed surgically to have lung cancer. Corresponding figures in 1997 and 1998 screening studies were 173 (3.9%) of 4425 and 25 (14%) of 173, and 136 (3.5%) of 3878 and 9 (7%) of 136, respectively. The sensitivity and specificity of detecting surgically confirmed lung cancer were 55% (22/40) and 95% (4960/5199) in 1996 and 83% (25/30) and 97% (4113/4252) in 1997 screening, respectively. 88% (55/60) of lung cancers identified on screening and surgically confirmed were AJCC stage IA. Our trial allowed detection of nearly 11 times the expected annual number of early lung cancers. Repeat CT allowed the detection of more aggressive, rapidly growing lung cancers, compared to those in the initial screening.

Adjuvant radiotherapy after complete resection of thymoma

Seventy patients were studied after undergoing complete resection of thymoma to determine the effect of postoperative adjuvant mediastinal radiotherapy on prognosis, with regard to clinical stage, histological type, and pleural factor. Pleural factor was defined as follows: p0, no adhesion to the mediastinal pleura; p1, fibrous adhesion to the mediastinal pleura without microscopic invasion; and p2, microscopic invasion of the mediastinal pleura. Recurrence of thymoma after complete resection was observed in 13 patients, 12 (92%) with pleural dissemination, 6 (46%) with local recurrence, and 2 (15%) with distant metastasis (types of recurrence are overlapping). In stage I and stage II p0 patients, no recurrence was observed, regardless of mediastinal radiotherapy. Whereas mediastinal irradiation completely prevented recurrence in stage II p1 patients, 4 (36.4%) nonirradiated stage II p1 patients experienced recurrence. In stage II p2 patients, 75% had pleural dissemination even after radiotherapy. A high incidence of recurrence was also observed in stage III, nonirradiated (25%) and irradiated (30%) patients. The results suggest that mediastinal irradiation for stage I and II p0 patients is not always necessary, and that therapy for stage II p1 is essential and also expected to decrease the recurrence rate. On the other hand, in stage II p2 and stage III thymomas, mediastinal irradiation is not sufficient to prevent pleural recurrence even after complete resection. Our classification based on pleural factor is useful for better selection of appropriate postoperative treatment for thymoma patients.

Is postoperative radiotherapy for thymoma effective

OBJECTIVE The authors determined the effect of postoperative mediastinal irradiation in preventing local and pleural recurrence of thymoma. SUMMARY BACKGROUND DATA The role of mediastinal irradiation after incomplete resection or biopsy of an invasive thymoma is well established. However, routine use of adjuvant mediastinal irradiation for patients with thymoma after complete resection remains controversial. METHODS During the 19-year period from 1973 to 1992, operations were performed on 89 patients with thymoma. Of these 89 patients, 80 patients who underwent gross complete tumor resection including adjacent tissues that appeared to be invaded by tumor were selected for this study. The effects of postoperative mediastinal irradiation on the recurrence rate of thymoma were analyzed according to histologic type, clinical stage, and whether adhesions to or invasion of the pleura or pericardium were present. RESULTS Recurrence of thymoma was observed in 13 of 80 (16.3%) patients. No recurrence was observed in 23 patients with noninvasive thymoma. In patients with invasive thymoma whose tumor was macroscopically adherent to the pleura but not microscopically invasive (p1), recurrence was observed in 4 of 11 patients (36.4%) when mediastinal irradiation was not performed, but in none of 10 patients who received mediastinal irradiation. However, in patients with microscopic pleural invasion (p2), a high recurrence rate was observed with mediastinal irradiation (40%, 6/15 patients) or without mediastinal irradiation (30%, 3/10 patients). Postoperative mediastinal irradiation for patients with microscopical invasion to pericardium (c2) did not decrease the recurrence rate. Analysis of the mode of recurrence showed that mediastinal irradiation may have been effective in preventing local recurrence, but it did not control the pleural dissemination that was observed in 12 of 13 recurrent cases. CONCLUSIONS Mediastinal irradiation is not necessary for patients with noninvasive thymoma. In patients with invasive thymoma, postoperative mediastinal irradiation is effective in preventing recurrence in patients with p1 thymoma, but not in patients with p2 or c2 tumors. Further adjuvant therapy should be performed to supplement mediastinal irradiation in patients with p2 or c2 thymoma, even after complete resection.

High-Resolution CT Features: Prognostic Significance in Peripheral Lung Adenocarcinoma with Bronchioloalveolar Carcinoma Components

Background: Based on Noguchi’s classification, adenocarcinomas with bronchioloalveolar carcinoma (BAC) components have a heterogeneous prognosis. However, until now, the prognostic factors in this tumor category have not been clarified. Objectives: We studied the prognostic significance of high-resolution CT (HRCT) findings in this tumor subtype. Materials and Methods: HRCT findings [lesion size, percentage of ground-glass opacity (GGO) areas in the lesion, presence or absence of lobulation, coarse spiculation, pleural tag, satellite lesion, air bronchogram, and site of the lesion], clinical data (age, gender and surgical method), and pathologic findings (degree of tumor differentiation and presence or absence of nodal metastasis) were analyzed in 52 consecutive patients with adenocarcinoma with BAC components <3 cm (mean, 1.7 cm). The patients included 32 women and 20 men with a mean age of 66 years. The results correlated with survival using univariate and multivariate analysis. The mean follow-up period was 41 months. Results: Nine (17%) of the 52 patients died of lung cancer. In univariate analysis, a significant difference was found for lobulation (p = 0.018), %GGO (p = 0.043), air bronchogram (p = 0.003), site of lesion (p = 0.034), degree of tumor differentiation (p = 0.001), and nodal metastasis (p = 0.040). Multivariate analysis using the 6 factors that were significant in univariate analysis as independent variables revealed that an air bronchogram (p = 0.010) and the degree of tumor differentiation (p = 0.008) were significant independent factors for survival. Conclusion: The presence of an air bronchogram on HRCT may have an independent prognostic significance in lung adenocarcinoma with BAC components.

Pulmonary artery remodeling modifies pulmonary hypertension during exercise in severe emphysema.

To clarify the relation between the vessel remodeling and the physiology of pulmonary circulation in chronic obstructive pulmonary disease (COPD), we studied the pulmonary hemodynamics at rest and during exercise (25W) and the morphology of pulmonary arteries with external diameters of 100-200 microm in ten patients with severe emphysema. The wall thickness (WT) was defined as the intima plus media. The percent WT of the external diameter (% WT) in emphysema (36.0 +/- 4.3%) was significantly increased compared with that (22.6 +/- 3.3%) in five control lungs. The % WT was not related to pulmonary arterial pressure (Ppa) at rest, but was highly correlated with exercise Ppa (r = 0.721, P = 0.02) and with deltaPpa (Ppa during exercise-Ppa at rest) (r = 0.899, P = 0.0004). These findings suggest that pulmonary artery remodeling leads to reduced recruitability and distensibility of pulmonary vessels and is closely related to exercise pulmonary hypertension.

Different Effects of Lung Volume Reduction Surgery and Lobectomy on Pulmonary Circulation

OBJECTIVE To clarify the effects of lung volume reduction surgery (LVRS) on cardiopulmonary circulation during exercise in comparison with pulmonary lobectomy for lung cancer. SUMMARY BACKGROUND DATA LVRS improves pulmonary function and dyspnea symptoms acutely in selected patients with heterogeneous emphysema. However, there are few data concerning the effects of LVRS on the cardiopulmonary circulation, especially during exercise. METHODS Pulmonary function tests and pulmonary hemodynamic study at rest and during exercise were performed before and 6 months after LVRS (seven patients) or pulmonary lobectomy (eight patients). In the workload test, an electrically braked bicycle ergometer (25 w) was used in the supine position for at least 2 minutes or until exhaustion or breathlessness developed. RESULTS After lung lobectomy, the values of vital capacity, percentage of predicted vital capacity, forced expiratory volume in 1 second, percentage of predicted forced expiratory volume in 1 second, residual volume/total lung capacity, and maximal voluntary ventilation deteriorated significantly. Six months after LVRS, however, vital capacity, percentage vital capacity showed no significant change, and forced expiratory volume in 1 second, percentage of forced expiratory volume in 1 second, diffusing capacity for carbon monoxide, and maximal voluntary ventilation showed marked improvement. Cardiac index was changed neither at rest nor during exercise in either group by the operation. Although postoperative pulmonary arterial pressure in the lobectomy group was significantly increased by the exercise, LVRS did not affect postoperative pulmonary arterial pressure at rest or during exercise. Pulmonary capillary wedge pressure in the lobectomy group showed no significant change after the operation, whereas LVRS ameliorated the marked elevation of pulmonary capillary wedge pressure observed during exercise. After lobectomy, significant increases in the pulmonary vascular resistance index were observed at rest and during exercise. LVRS markedly increased the pulmonary vascular resistance index at rest but not during exercise. In the lobectomy group, the postoperative flow-pressure curve moved upward, and its gradient became steeper than the preoperative one. In the LVRS group, the curve moved upward in a parallel fashion. These results show that much more right-sided heart work is needed to achieve the same cardiac output against higher pulmonary arterial pressure, not only after lobectomy but also LVRS. CONCLUSION The current study demonstrated that the effects of LVRS on the cardiopulmonary circulation were not negligible, especially during exercise, and successful LVRS may depend on improved respiratory function and also preserved cardiac function that can tolerate the damage to the pulmonary vascular bed induced by this operation.

Cardiopulmonary function after pulmonary lobectomy in patients with lung cancer

The effects of pulmonary lobectomy on cardiopulmonary function were investigated in 9 patients with lung cancer. Hemodynamic studies at rest and during exercise were performed before and 4 to 6 months after the operation. Differences in hemodynamics between before and after operation were observed with respect to heart rate, pulmonary arterial pressure, pulmonary vascular resistance index, and stroke volume index. Heart rate, pulmonary arterial pressure, and pulmonary vascular resistance index were significantly increased after operation, whereas stroke volume index was significantly decreased. It is thought that cardiac index was preserved by the increase in heart rate despite a decrease in stroke volume index associated with the decreased pulmonary vascular bed after the operation. When driving pressure and cardiac index were studied after operation, the pressure at rest and during exercise was higher, and the pressure-flow curve increased more steeply, as compared with the preoperative values. These results suggest a significant deterioration in cardiopulmonary function after lobectomy. As the patient characteristics were heterogeneous (five lobectomies and four bilobectomies), and their findings are limited, additional studies may be necessary in the future.

Methotrexate stimulates lung epithelial cells to release inflammatory cell chemotactic activities.

Methotrexate-induced pneumonitis has been reported as an infrequent but potentially serious complication of therapy in a variety of malignant and benignconditions. Because inflammatorycell infiltration is concerned with the development of methotrexate-induced pneumoinitis, and because airway epithelial cells participate in the orchestration of lung inflammation, the authors determined whether methotrexate might stimulate airway epithelial cells (A549 cells) to release neutrophil, monocyte, and eosinophil chemotactic activities (NCA, MCA, and ECA). A549 cells released NCA, MCA, and ECA in a dose- and time-dependent manner in response to methotrexate. Partial characterization revealed the heterogeneity of NCA, MCA, and ECA. The release of chemotactic activity was blocked by lipoxygenase inhibitors and cycloheximide. NCA was inhibited by leukotriene (LT) B 4 receptor antagonist, and anti-interleukin (IL)-8 and granulocyte colony-stimulatingfactor (G-CSF) antibodies. MCA was attenuated by LTB 4 receptor antagonist, and anti-monocyte chemoattractant protein (MCP)-1 and granulocyte-macrophage CSF (GM-CSF) antibodies. ECA was attenuated by LTB 4 receptor antagonist, and anti-IL-8 and GM-CSF antibodies. The release of IL-8, G-CSF, MCP-1, GM-CSF, and LTB 4 from A549 cells significantly increased in response to methotrexate. The mRNA expression of IL-8 and MCP-1 was augmented by methotrexate stimulation. These data suggest that type II epithelial cells may modulate inflammatory cell recruitment into the lung by releasing NCA, MCA, and ECA in response to methotrexate.

Thin-rim enhancement in Gd-DTPA-enhanced magnetic resonance images of tuberculoma: A new finding of potential differential diagnostic importance

The article describes rim enhancement seen on Gd-DTPA-enhanced magnetic resonance (MR) images of two patients with tuberculoma. Pathologic examination of the surgical specimens disclosed that the peripheral portion of the tuberculoma, which showed contrast enhancement, was composed mainly of a fibrous capsule and epithelioid granulomas and that the central zone, which showed no contrast enhancement, was composed of caseous necrotic material. In a retrospective study of MR images from 20 consecutive cases of surgically proven bronchogenic carcinoma, none showed a thin enhancing rim on postcontrast MR images. Although confirmation of these findings must await further experience, the postcontrast MR findings described here may prove to be of value in distinguishing tuberculoma and possibly other granulomatous lesions from bronchogenic carcinoma.

Image processing in the digital tomosynthesis for pulmonary imaging

Digital tomosynthesis makes it possible to reconstruct multiple tomographs from digital data obtained during a single tomographic motion and permits digital processing, which adds a number of special advantages to the well-known advantages of conventional tomography. We performed digital tomosynthesis with a fluororadiographic TV unit with tomographic function which was capable of producing pulsed low-and high-energy X-rays alternately, and we studied digital image processing to improve the image clarity of the reconstructed tomographs. To identify the optimal parameters for processing image data by means of spatial frequency filtration we evaluated the spatial frequency distribution of image data in linear tomographs of the lung, and on the basis of the results of this study we developed several types of digital image processing to reduce tomographic blur and system noise, to improve visualisation of faint opacities, to reduce resistant tomographic blur as well as overall blur, and to generate low-noise bone images based on dual-energy subtraction tomosynthesis.