Shodayu Takashima

Mass screening for lung cancer with mobile spiral computed tomography scanner

BACKGROUND The incidence of and mortality from lung cancer have increased steadily. Most lung cancers are not localised when first detected, but early detection is mandatory to improve prognosis. Since curable early cases are hard to visualise with conventional chest radiography, a new diagnostic means must be found. We assessed whether population-based mass screening with a spiral computed tomography scanner could contribute substantially to detection of smaller cancers, and decrease mortality. METHODS In 1996, we screened in a mobile unit 5483 individuals from the general population of Matsumoto, Japan, aged between 40 years and 74 years who had undergone annual chest radiography (miniature fluorophotography) and cytological assessment of sputum. All participants had a low-dose X-ray spiral computed tomography (CT) scan of the thorax; 3967 also underwent miniature fluorophotography. We compared smokers and non-smokers. Further assessments were done for probably benign but suspicious lesions; suspicion of cancer; and indeterminate small nodules by chest radiography and conventional CT, with additional transbronchial biopsy when possible. Thoracotomy was recommended when it was strongly suspected that the patients had lung cancer. FINDINGS 19 patients were diagnosed as having lung cancer--14 with suspicion of lung cancer, three with benign but suspicious lesions, and two with indeterminate small nodules. 18 cases were surgically confirmed, and one was clinically diagnosed. The mean size of lesions was 17 mm (range 6-47). In four of 19 patients, lung abnormality was seen on CT and miniature fluorophotography. The lung-cancer detection rate with CT was 0.48%, significantly higher than the 0.03-0.05% for standard mass assessments done previously in the same area. CT missed one case that was found solely on a sputum cytology examination. INTERPRETATION Our results show that miniature fluorophotography or conventional chest radiography, which have been the main diagnostic techniques for lung cancer, showed few small cancers. CT was more accurate in mass screening for lung cancer and led to early detection and an accurate diagnosis of lung cancer, and should be considered in future health plans.

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.

Prognostic significance of high-resolution CT findings in small peripheral adenocarcinoma of the lung: a retrospective study on 64 patients

OBJECTIVE We studied the prognostic importance of high-resolution CT (HRCT) findings in lung adenocarcinomas. PATIENTS AND METHODS HRCT findings (lesion size, percentage of ground-glass opacity (GGO) areas of lesion, and presence or absence of lobulation, coarse spiculation, air space, pleural tag, and multiplicity of lesion), clinical data (age and surgical method), and pathologic findings (tumor subtypes and presence or absence of nodal metastasis) in 64 consecutive patients with 64 peripheral adenocarcinomas of 20 mm or less (mean, 13 mm), including 36 women and 28 men with a mean age of 64 years were analyzed and correlated with survival of the patients using Kaplan-Meier method and stepwise Cox proportional hazards modeling. Follow-up periods of the patients ranged from 6 to 45 months (mean, 22 months). Tumors were classified into six subtypes (types A-F) according to tumor growth patterns defined by Noguchi et al. RESULTS Six (9%) of the 64 patients died of lung cancer. In univariate analyses, a significant difference was noted for lesion size (P=0.043), the percentage of GGO areas (P=0.005), and tumor subtypes (P=0.006). Lesion size of <15 mm (n=35), a lesion with GGO areas of >57% (n=36), and type A (n=16) or type B adenocarcinomas (n=16) indicated a significantly better survival. In multivariate analyses using these three parameters as independent variables, the percentage of GGO areas was the only significant independent factor for survival (P=0.044, relative risk=0.95). CONCLUSION GGO areas measured on HRCT may have an independent prognostic significance of small adenocarcinomas of the lung.

Nonpalpable lymph nodes of the neck: Assessment with US and US-guided fine-needle aspiration biopsy

Ultrasound (US) and US‐guided fine‐needle aspiration biopsy (FNA) were performed in 91 nonpalpable neck nodes of 70 patients, 93% of which had known malignancy. Various sonographic findings were evaluated for predicting malignancy. The accuracy of US‐guided FNA for detecting malignancy was 88%, with 96% sensitivity and 94% specificity. The ratio of minimal to maximal axial diameters of a node was most valid for predicting malignancy with US. A ratio of more than 0.55 yielded the highest accuracy (80%) (92% sensitivity, 63% specificity). Addition of any other factors to this criterion did not improve its accuracy. US and US‐guided FNA are accurate for the assessment of nonpalpable neck nodes. Lymph nodes with a round configuration should be biopsied in patients with known malignancy.

Atypical adenomatous hyperplasia of the lung: correlation between high-resolution CT findings and histopathologic features.

Abstract We describe herein the CT features of atypical adenomatous hyperplasia (AAH) of the lung and its histopathological characteristics. Among 17,919 individuals screened for lung cancer by CT scanning, ten AAH nodules were detected in nine asymptomatic subjects. On high-resolution CT, the lesions measured from 6 × 6 mm to 15 × 17 mm and their CT number ranged from –500 to –760 HU. The AAHs appeared as round nodules with smooth and distinct borders and showed a ground-glass opacity. Plain chest radiographs failed to identify all lesions. Histopathologically, AAH lesions showed atypical epithelial cell proliferation along slightly thickened alveolar septa. Whereas it is often easy to differentiate these nodules from inflammatory and benign lung lesions, histopathological examination remains at present the only method to differentiate AAH from lung cancers.

Discrimination of subtypes of small adenocarcinoma in the lung with thin-section CT.

We studied the usefulness of thin-section CT in discriminating two categories of adenocarcinoma in the lung. Thin-section CT findings, such as, lesion size, ground-glass opacity (GGO) areas of lesion and presence or absence of lobulation, coarse spiculation, air bronchogram, small air space, or pleural tag of lesion in 62 consecutive patients with 62 adenocarcinomas (35 type A or B tumors (Noguchis classification) and 27 type C tumors) of < or =20 mm, including 36 women and 26 men with a mean age of 64 years were analyzed. We performed stepwise logistic modeling using all the CT findings as independent variables to estimate the significant factors for discriminating type C from type A or B tumor. Lesion size in type C tumors was significantly (P<0.001) greater than that in type A or B tumors. GGO areas in type C tumors were significantly (P<0.001) smaller than that in type A or B tumors. The prevalence of coarse spiculation, air bronchogram, and pleural tag in type C tumors was significantly greater (P=0.001, 0.010, and <0.001, respectively) than that in type A or B tumors. Logistic modeling revealed that the GGO area was the only significant factor for discriminating two categories (P<0.001). Using the percentage of GGO areas for predicting type C tumor, 40% or less showed the highest accuracy of 85% with 70% sensitivity and 97% specificity. GGO areas of 30% or less had no false-positive diagnosis (100% specificity) with 81% accuracy but its sensitivity was low (56%). Thin-section CT was useful in discriminating two categories of adenocarcinoma in the lung.

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.

Primary Thyroid Lymphoma: Evaluation with Us, Ct, and Mri

Objective Our goal was to determine the most effective radiologic workup in diagnosing and staging primary thyroid lymphomas and the value of knowing the extent of tumors for prognostic purposes. Materials and Methods Magnetic resonance imaging, CT, US, and fine-needle aspiration (FNA) biopsy (palpation- or US-guided) findings were retrospectively reviewed in 14 patients with primary thyroid lymphomas (5 palpable, 9 nonpalpable). Survival was correlated with the presence or absence of extrathyroidal spread of lymphoma. Results Thyroid lymphomas were detected in all patients with US and 12 (86%) each with CT and MRI. Histopathologic diagnosis was obtained with FNA in 11 patients (79%) and with surgical procedures in 3. Magnetic resonance imaging correctly diagnosed tumor involvement of the lymph nodes (four of four patients), muscle (five of five), esophagus (one of one), internal jugular vein (one of one), and carotid artery (one of one). Muscle invasion was missed with CT in one patient. Ultrasound was not accurate for diagnosing tumor invasion of the esophagus, carotid artery, and lymph nodes. The survival of patients without extrathyroidal spread was significantly (p < 0.05) better than that of patients (n = 5) with extrathyroidal spread. Conclusion Palpable thyroid masses should undergo palpation-guided FNA for diagnosis and nonpalpable masses US-guided FNA. Tumor extent and staging should be determined with MRI, which will contribute to initiating appropriate therapy and prediction of prognosis. Index Terms Thyroid, neoplasms—Lymphoma—Magnetic resonance imaging—Ultrasound—Computed tomography.

Small peripheral carcinomas of the lung: thin-section CT and pathologic correlation

Abstract. The aim of this study was to clarify the thin-section CT features of small peripheral carcinomas of the lung on the basis of pathologic findings of tumor growth patterns. Thin-section CT and pathologic correlation was evaluated in 19 patients with surgically verified small peripheral carcinomas of the lung ( < 20 mm in size) that had been detected in a screening trial for lung cancer using spiral CT. Four thin-section CT types of nodules were observed: (a) type L1 (4 of 19, 21 %), a fairly well-defined nodule with ground-glass attenuation, corresponding to tumor lepidic growth without alveolar collapse; (b) type L2 (4 of 19, 21 %), a partly lobulated nodule with a low but inhomogeneous attenuation, corresponding to tumor lepidic growth with scattered foci of alveolar collapse; (c) type L3 (4 of 19, 21 %), an ill-defined nodule with an irregularly shaped higher-density central zone in a ground-glass attenuation peripheral zone, accompanied by convergence of the bronchovascular structures from the surrounding lung parenchyma, which corresponded to desmoplastic response in the central zone and to tumor lepidic growth in the peripheral zone; and (d) type H (7 of 19, 37 %), a well-defined nodule with a solid homogeneous attenuation, corresponding to tumor hilic growth. Thin-section CT features of small peripheral carcinomas of the lung can be classified into four types, based on the density distribution of the tumor, which reflect the histologic findings.

Factors affecting the radiologic appearance of peripheral bronchogenic carcinomas

The use of high-resolution computed tomography and magnetic resonance imaging have allowed the detailed description of morphologic findings associated with lung cancer. In particular, the desmoplastic response of lung tissue to tumor growth has not been adequately described. This article reviews roentgenologic and pathologic correlations of primary lung carcinomas. An irregular or indistinct tumor margin may be caused by tumor infiltration, an irregular desmoplastic response to the tumor growth, or irregular contraction in the central portion of the tumor. Solid tumor growth, on the other hand, may be associated with a well-defined tumor margin, with or without displacement of adjacent anatomical structures.