Comparison of [(18)F]FDG PET and (201)Tl SPECT in evaluation of pulmonary nodules.

Recent reports have indicated the value of [(18)F]FDG PET and (201)Tl SPECT in diagnosing lung cancer. In this study, we compared the diagnostic value of FDG PET and (201)Tl SPECT in the evaluation of pulmonary nodules. METHODS: Sixty-three patients with 66 pulmonary nodules suspected to be lung cancer on the basis of chest CT were examined by FDG PET and (201)Tl SPECT (early and delayed scans) within a week of each study. For semiquantitative analysis, the standardized uptake value (SUV) or the tumor-to-nontumor activity ratio (T/N) (or both) was calculated. All of these lesions were completely removed thoracoscopically or by thoracotomy and were examined histologically. RESULTS: Fifty-four nodules were histologically confirmed to be malignant tumors, and 12 were benign. Both techniques delineated focal lesions with an increase in tracer accumulation in 41 of 54 lung cancers. (201)Tl SPECT on early or delayed scans (or both) identified 4 additional lung cancers that FDG PET images did not reveal: 3 bronchioloalveolar carcinomas and a well-differentiated adenocarcinoma. FDG PET identified 3 additional lung cancers that (201)Tl SPECT images did not reveal; 2 of these lung cancers were <2 cm in diameter. The mean FDG SUV and T/N of bronchioloalveolar carcinomas (2.06 +/- 0.76 and 3.49 +/- 1.03, respectively) were significantly lower than those of poorly differentiated adenocarcinomas (5.55 +/- 2.01 [P = 0.026] and 8.23 +/- 2.16 [P = 0.01], respectively). However, no significant difference was found in (201)Tl T/N on early and delayed scans between bronchioloalveolar carcinomas (1.64 +/- 0.29 and 1.87 +/- 0.42, respectively) and poorly differentiated adenocarcinomas (1.58 +/- 0.32 and 2.76 +/- 1.36, respectively). Of the 12 benign nodules, FDG PET and (201)Tl SPECT showed false-positive results for the same 7 benign nodules (58.3%) (4 granulomas, 1 sarcoidosis, 1 inflammatory pseudotumor, and 1 aspergilloma). Negative FDG PET findings and positive (201)Tl SPECT findings were obtained only for bronchioloalveolar carcinomas or a well-differentiated adenocarcinoma but not for other histologic types of lung cancers or benign pulmonary nodules. CONCLUSION: No significant difference was found between FDG PET and (201)Tl SPECT in specificity for the differentiation of malignant and benign pulmonary nodules. The degree of differentiation of lung adenocarcinoma correlated with FDG uptake but not with (201)Tl uptake. Bronchioloalveolar carcinoma (a well-differentiated, slow-growing tumor) findings typically were positive with (201)Tl but were negative with FDG. The combination of FDG PET and (201)Tl SPECT may provide additional information regarding the tissue characterization of pulmonary nodules.     

Diagnosis of pancreatic cancer using 201Tl-chloride and a three-head rotating gamma camera SPECT system]

201Tl SPECT was performed on 17 patients with pancreatic cancer or chronic pancreatitis using a three-head rotating gamma camera SPECT system. In 7 of 10 patients with pancreatic cancer, the lesions were clearly delineated by 201Tl SPECT. Whereas the lesion of 30 mm in diameter was visualized, a large tumor of 80 mm in diameter could not be visualized. Namely, it was thought that 201Tl uptake by pancreatic cancer might be well correlated with tumor blood flow and/or its histological subtype rather than with tumor size. In 5 of 7 patients with chronic pancreatitis, no uptake by the pancreas was shown. The sensitivity, specificity, and accuracy in diagnosing pancreatic cancer by 201Tl SPECT were 70%, 71%, and 71%, respectively. The present results obtained by 201Tl SPECT were thought satisfactory enough to evaluate pancreatic cancer under the present conditions where there was no useful imaging agent for visualizing pancreatic cancer by SPECT. 201Tl SPECT is expected to be a new diagnostic tool for investigation of pancreatic tumorous lesion.     

Single photon emission computed tomography using201Tl chloride in pulmonary nodules: Comparison with67Ga citrate and99mTc-labeled hexamethyl-propyleneamine-oxime

A single photon emission computed tomography (SPECT) with 201Tl chloride (Tl-201) was carried out prospectively in 50 patients with pulmonary nodules and its diagnostic value was compared with those of 67Ga citrate (Ga-67) and 99mTc-labeled hexamethylpropyleneamine-oxime (Tc-99m-HMPAO). Tl-201 SPECT provided 88% (early)-91% (delayed) sensitivity, 85% (early and delayed) specificity and 87% (early)-89% (delayed) accuracy. The sensitivity of the Tl-201 planar image was 56 (early)-62% (delayed), which was significantly lower than that of SPECT. Delayed SPECT images at 2 hour postinjection were more preferable to disclose the malignant pulmonary nodule than early SPECT images at 15 minutes postinjection. The application of SPECT with Ga-67 failed to improve the sensitivity of planar imaging for malignant pulmonary nodules. Tc-99m-HMPAO was concentrated in 62% of 13 patients with malignant pulmonary nodules, which was slightly higher than Ga-67 in 54% of 28 patients. In an analysis of the histologic types of lung cancer, the sensitivity of Tl-201 was not significantly different in all types. On the other hand, Ga-67 was positive only in 25% of 12 patients with adenocarcinoma. A combination of SPECT and Tl-201 is the best choice among routine scintigraphic techniques for depicting malignant pulmonary nodules. The Tl-201 SPECT image may play a complementary role in the characterization of pulmonary nodules which are revealed on a plain radiograph and computed tomography.     

Initial application of respiratory-gated 201Tl SPECT in pulmonary malignant tumours

AIM: Respiratory-gated thallium-201 chloride (201Tl) single photon emission computed tomography (SPECT) was used in preliminary investigations to reduce the adverse respiratory motion effects observed on standard ungated SPECT images and to obtain reliable fusion images with computed tomography (CT) in patients with malignant lung tumours. METHODS: Fifteen patients with primary lung cancer (n=10) or metastatic lung tumours (n=5) underwent gated SPECT 20 min after intravenous injection of 148 MBq 201Tl, using triple-headed SPECT and laser light respiratory tracking units. Projection data were acquired by a step and shoot mode, with 20 stops over 120 degrees for each detector and a preset time of 30 s for each 6 degrees stop. Gated end-inspiratory and ungated images were obtained from 1/8 data centred at peak inspiration for each regular respiratory cycle and for the full respiratory cycle data, respectively. The degree and size of tumour 201Tl uptake were compared between these images by regions of interest (ROI) analysis. Gated SPECT images were registered with rest inspiratory CT images using an automated three-dimensional (3D) image registration tool. Registration mismatch was assessed by measuring the 3D distance of the centroid of 14 201Tl-avid peripheral tumours. Attenuation correction of gated SPECT images was performed using CT attenuation values of these fusion images. RESULTS: Gated SPECT images improved image clarity and contrast of tumour 201Tl uptakes compared with ungated images, regardless of the decreased count density due to the use of gated images. The lesion-to-normal (L/N) lung count ratios and ROI size in 18 well-circumscribed 201Tl-avid tumours were significantly higher and smaller on gated images (both P<0.0001). Gated images showed positive 201Tl uptakes in two small peripheral tumours, although negative on ungated images, and demarcated 201Tl-avid tumours from adjacent 201Tl-avid lymph node or surrounding focal 201Tl uptakes caused by other pathology, although these were not clearly demarcated on ungated images. On fusion images, gated images yielded a significantly better SPECT-CT matching compared with ungated images (P<0.0001). Fusion images accurately localized 201Tl uptakes of tumour/lymph node and other focal pathological/physiological conditions. Attenuation-corrected gated SPECT images further facilitated the detection of 201Tl uptake in small or deeply located lesions, with significantly increased L/N ratios. CONCLUSION: Gated SPECT images facilitate the detection of tumour 201Tl uptake and provide reliable SPECT-CT fusion images, which contribute to accurate interpretation and attenuation correction of Tl SPECT images.     

Usefulness of 201Tl SPECT in the predication of mediastinal lymph nodes metastasis in patients with non small cell lung carcinoma (NSCLC)

Predictivity of mediastinal lymph nodes metastasis of 201Tl SPECT were examined before operation in 113 patients with non-small cell lung cancer (69 adenocarcinoma, 31 squamous cell carcinoma, 10 large cell carcinoma, 2 bronchiolo-alveolar carcinoma, 1 neuroendocrine cell carcinoma). Patients were classified into two groups, with or without lymph nodes metastasis according to the pathological diagnosis. We calculated parameters of 201Tl SPECT early ratio, delayed ratio, retention index (RI) and maximal diameters. In addition, we calculated optimal cut-off value of RI to estimate the mediastinal lymph nodes metastasis. Mediastinal lymph nodes metastasis was confirmed pathologically in 62 patients. ER and DR did not show any statistical significance between two groups. Maximal diameters of primary tumor were also comparable between two groups. RI was significantly higher in mediastinal lymph node metastasis positive group compared to that in mediastinal lymph node metastasis negative group. The sensitivity (Sen), specificity (Spe), positive predictive value (PPV), negative predictive value (NPV) and accuracy (Acc) of 201Tl SPECT were 82.2%, 82.3%, 85.0%, 79.2% and 82.3%. These parameters were similar of higher than 72.6%, 82.4%, 83.3%, 71.2% and 77.0% of chest CT. The RI of 201Tl SPECT was useful tool for predicting lymph nodes metastasis in non-small cell lung cancer. The optimum cut-off value of RI in the prediction of mediastinal lymph nodes metastasis was 35%. We should take into account of upstaging in cases with higher RI (>35%).     

Thallium-201 single photon emission computed tomography in the evaluation of suspected lung cancer

Thallium-201 SPECT was performed in 30 patients with suspected lung cancer. Both early and delayed scans demonstrated abnormal accumulation in all of 23 malignant pulmonary lesions including 21 lung cancer and in two of seven benign conditions. There were significant differences in delayed ratio (uptake ratio of the lesion to the normal lung on delayed scan) and retention index (degree of retention in the lesion) between lung cancer and benign conditions, respectively (p less than 0.01, p less than 0.05). The delayed ratio and retention index revealed that adenocarcinoma showed higher 201Tl accumulation than squamous cell carcinoma and small cell carcinoma (p less than 0.05) and 201Tl clearance in squamous cell carcinoma was faster than in the other two (p less than 0.05). Mediastinal involvement was detected in five of seven patients on delayed scans. The smallest lesion depicted was 1.5 cm in diameter. Two false negatives had small metastases less than 1.0 cm in diameter. This method seems to be useful to detect lung cancer, to differentiate malignant from benign lesions, and to evaluate mediastinal involvement from lung cancer.     

Differential uptake of TI-201 by small-cell lung cancer in a patient with pneumoconiosis-related pulmonary nodules.

A 68-year-old man with pneumoconiosis was thought to have small-cell lung cancer based on the results of a biopsy of a bone tumor. Three pulmonary nodules were observed on a chest radiograph. Compared with a chest radiograph taken 4 months earlier, one of the nodules had grown. It was difficult to differentiate this nodule from pneumoconiosis-related benign pulmonary nodules from the appearance on the chest radiograph and CT. Ga-67 scintigraphy and TI-201 lung SPECT were performed to characterize these nodules. TI-201 SPECT showed differential high uptake in the enlarged nodule, whereas Ga-67 scintigraphy showed equally intense uptake in all these nodules. Transbronchial biopsy of the nodule that showed high TI-201 uptake revealed cancer cell nests against a background of interstitial fibrosis. The pathologic diagnosis was small-cell lung cancer that had developed in lung scar tissue. This case suggests the utility of TI-201 in scintigraphic assessments of pneumoconiosis-related pulmonary nodules when lung cancer is suspected.     

Thallium-201 SPECT in advanced non-small cell lung cancer: In relation with chemotherapeutic response,survival, distant metastasis and p53 status

PURPOSE: The aim of this study was to evaluate the relationship between 201Tl tumor uptake, chemotherapeutic response, metastasis, p53 status and survival in non-small cell lung cancer (NSCLC). METHODS: A total of 23 patients underwent 201Tl SPECT. In 9 patients, 2nd 201Tl SPECT study were performed 1 week after the 3rd cycle of chemotherapy (ChT), and early (ER) and delayed (DR) tumor/normal lung ratios and retention indices (RI) were obtained. In 15 patients p53 status was assayed with immuno-histochemical staining. The patients were divided into subgroups after the 3rd cycle of ChT; responders [R(+) (n = 10)] and non-responders [R(-) (n = 13)], distant metastasis [(M1) n = 11] and [(M0) n = 12], and mutant p53 status [p(+) n = 7, p53(-) n = 8]. RESULTS: The differences for ER, DR and RI values between all of the subgroups were not statistically significant. ER and DR of responders decreased significantly after ChT; from to 2.46 to 1.36 (p = 0.04) and 2.29 to 1.53 (p = 0.04), respectively. In the non-responder group, both ER and DR slightly increased after ChT (p > 0.05). CONCLUSION: Our results suggest that in NSCLC, there was a weak correlation between higher 201Tl ratios and positive response to chemotherapy, absence of distant metastasis, and p53(-) status. Significant 201Tl uptake decrease after chemotherapy indicates that delayed 201Tl uptake can be used in evaluating the chemotherapeutic response.     

Relationship between cancer cell proliferation and thallium-201 uptake in lung cancer

Although thallium-201 (201Tl) uptake is related to perfusion in many normal tissues, the biologic rationale for 201Tl uptake in tumors is uncertain. To determine if tumor uptake is related to cell proliferation, we correlated the relative retention of 201Tl in lung tumors with expression of Ki-67, an indicator of cell proliferation. METHODS: Sixty patients with lung tumors, included small cell carcinoma (n = 8) and non-small cell carcinoma (n = 52), underwent 201Tl single photon emission computed tomography (SPECT) imaging. The 201Tl lesion uptake was determined on early and delayed images and the radiotracer retention index (RI) was calculated. Tumor specimens were obtained at surgery or bronchoscopy. The cell proliferation ratio was estimated with MIB-1, a monoclonal antibody that recognized the nuclear antigen Ki-67. RESULTS: The average 201Tl index was 2.13+/-0.61 (early) and 2.46+/-0.83 (delayed). The average RI was 17.44+/-35.01. Overall, the 201Tl index (delayed) and the cancer cell proliferation were correlated (r = 0.70, p < 0.0001). Of interest, there was a significant correlation (r = 0.872, p < 0.0005) between the 201Tl index on delayed images and the cell proliferation ratio in patients with small cell but not non-small cell lung carcinoma. The 201Tl index (delayed) was significantly higher (p < 0.0001) in patients with small cell lung carcinoma than in patients with non-small cell lung carcinoma. CONCLUSION: 201Tl imaging appears to be useful for evaluating patients with small cell lung carcinoma but not non-small lung carcinoma, and is correlated with the monoclonal antibody MIB-1, a marker of cell proliferation.     

Differentiation of prostate cancer and benign prostatic hyperplasia: the clinical value of<Superscript>201</Superscript>Tl SPECT—A pilot study

PURPOSE: Thallium-201 (201Tl) is a recognized tumor-imaging agent; however, the usefulness of 201Tl in prostate cancer has not been studied. The purpose of this preliminary study was to evaluate the efficacy of 201Tl single-photon emission computed tomography (SPECT) imaging for differentiating prostate cancer from benign prostatic hyperplasia (BPH). METHODS: 201Tl pelvic SPECT was performed in 10 patients (aged 64-78 years) with biopsy-proven BPH before transurethral resection of the prostate and 15 patients (aged 65-81 years) with biopsy-proven prostate cancer prior to any therapeutic modality or invasive surgical procedures for treatment of their prostate cancer. RESULTS: From the 15 patients with prostate cancer, 201Tl pelvic SPECT detected prostate cancer in 13 (86.7%) but not in 2 (13.3%) patients with Gleason scores of 5 (2 + 3). In contrast, all 10 patients with BPH (100.0%) had negative results of 201Tl pelvic SPECT. CONCLUSION: Our study showed that 201Tl pelvic SPECT scan is very helpful in distinguishing between prostate cancer and BPH.     

Gd-DTPA增强MRI诊断肺内结节

目的：研究Gd－DTPA增强MRI在孤立性肺结节鉴别诊断中的作用。材料和方法：对26例≤3cm的孤立肺内结节（肺癌16例，结核10例）进行了常规和动态Gd－DTPA增强MRI检查，测量病灶的增强程度，分析MRI表现并与病理对照。结果：16例肺癌在静脉注入Gd－DTPA后均有强化，表现为实体均匀（9例）和不均匀（7例）增强，而多数（8／10）结核球表现为环形增强。肺癌平均增强71％，与结核球（23％）有显著差异。肺癌结节的动态增强曲线也与结核球不同。结论：肺癌与结核球的MRI增强形态和增强程度不同，对鉴别诊断很有帮助。     

Thallium-201 myocardial SPECT findings at rest in sarcoidosis

In 41 patients with sarcoidosis (diagnosed according to criteria recommended by the Committee on Diffuse Pulmonary Disease, Ministry of Health and Welfare, Japan 1988), thallium-201 (²⁰¹Tl) myocardial SPECT was performed to investigate: (1) the ability of²⁰¹Tl SPECT to detect cardiac involvement of sarcoidosis with images recorded at rest and 2 hours later, and (2) the relationships between²⁰¹Tl myocardial SPECT findings and the activity of sarcoidosis or endomyocardial biopsy findings. As to the abnormal findings in²⁰¹Tl myocardial SPECT, (1) a low density area was seen in 13 of 41 cases (31.7%) and non-uniform uptake was found in 17 cases (41.5%), (2) the mean washout ratio (n=39) was 16.5±7.4%, which is significantly (p < 0.05) lower than that found in normal subjects, 23.9±7.5 % (n=10). Of the 19 patients judged visually to be normal, 5 patients had a reduced mean washout ratio less than 12%. Thus, the incidence of abnormal findings including all types of abnormality, on²⁰¹Tl myocardial SPECT in sarcoidosis was 63.4% (26/41 cases). In studying the relationship between²⁰¹Tl myocardial SPECT findings and the activity of sarcoidosis (as measured by the serum ACE (angiotensin converting enzyme) or lysozyme level, or the presence of more than 30% symphocyte fraction in BALF (broncho-alveolar lavage fluid)), 20 (80%) of 25 cases with²⁰¹Tl abnormality were judged to be active sarcoidosis, while only 6 (37.5%) of 16 cases with normal findings on²⁰¹Tl SPECT were judged to be active. This suggests that there is a significant (p < 0.01) relationship between the presence or absence of an abnormal finding on²⁰¹Tl myocardial SPECT and the activity of sarcoidosis. Among 13 patients examined by endomyocardial biopsy, 10 patients had abnormal findings on²⁰¹Tl myocardial SPECT and 7 of these 10 patients had no histological evidence of cardiac sarcoidosis. In all of these 7 patients, however, sarcoidosis was judged to be active. This suggest that endomyocardial biopsy is of limited value in the diagnosis of cardiac sarcoidosis.     

201Tl SPECT in the detection of mediastinal lymph node metastases from lung cancer

201Tl SPECT was performed to detect mediastinal involvement in 80 patients with lung cancer who underwent surgery within a week after the SPECT study. Out of 29 patients with mediastinal involvement 16 (55%) were positive on the 201Tl early scan at 15 min postinjection and 22 (76%) were positive on the delayed scan at 3 h. These metastatic lymph nodes tended to be visualized much better on the delayed scan. In all patients with true positive results on the delayed scan, the mediastinal lymph nodes were plural, with a lesion of more than 14 mm in size. Seven false negative cases were found to have metastatic lesions less than 12 mm in size. Both the early and delayed scans showed false positive accumulation in six of 51 patients without mediastinal involvement (specificity 88%). Thus the overall accuracy for the delayed scan was 84%. The 201Tl delayed SPECT is thought to be a good noninvasive method for assessing mediastinal lymph node metastases from lung cancer.     

MicroRNA在肺小结节鉴别诊断中的研究进展

近些年,随着低剂量计算机断层扫描（low-dose computed tomography,LDCT）的广泛应用,肺癌早期检出率大幅提升,如何有效鉴别肺结节良恶性成为肺癌早期诊断的关键问题之一,尤其是直径＜10 mm的肺小结节。液体活检以其标本易于获得、可重复检测和非侵入性的特点有望与其它技术成为肺癌早期联合诊断的手段。microRNA作为液体活检的重要成员,在鉴别肺小结节良恶性方面可发挥重要作用。在此,本文对近年来关于microRNA在肺癌早期诊断及预后判断中相关研究进行了综述,以期为进一步研究microRNA参与多层次、多维度肺小结节鉴别诊断提供参考。     

螺旋CT薄层扫描并MPVR重建对孤立性肺结节的诊断价值

目的:探讨螺旋CT肺薄层扫描并多层面重建对孤立性肺结节的诊断价值。方法:对86例SPN患者进行螺旋CT规范化检查,并使用多层面重建(MPVR)技术重建观察。病灶结节直径选在0.8~3.0cm,病历均经临床手术或肺穿刺活检病理证实。其中恶性59例,均为原发性肺癌,包括腺癌25例、鳞癌17例、细支气管肺泡癌10例、小细胞未分化癌7例;良性病变27例,包括结核灶13例、炎性假瘤9例、错构瘤5例。结果:86例SPN的CT征象中,分叶征和棘突或毛刺征多出现于恶性结节,与病理和随访结果对比,螺旋CT薄层扫描并MPVR重建判断肺小结节良恶性的准确率、灵敏度、特异性、阳性预测值和阴性预测值分别为75.6%、76.3%、74.1%、86.5%、58.8%。结论:SCT肺薄层扫描并MPVR重建能显示更多的SPNCT征象,对SPN的良恶性诊断有较高的诊断价值。     

Thallium-201 SPECT increases detectability of thyroid cancer metastases

Thallium-201- (201Tl) chloride is known to accumulate in metastatic foci of differentiated thyroid carcinoma, but small and deep-seated lesions are generally not detectable by planar imaging. We have evaluated the use of 201Tl-chloride single-photon emission computed tomography (SPECT) in 41 post-thyroidectomy patients with differentiated thyroid carcinoma and one with medullary carcinoma; planar imaging alone was done in eight additional patients (total 50). Of 20 patients with known metastatic disease, planar 201Tl images were positive in 12 (60%) but SPECT revealed an additional 5 (25%) who had metastases (total 85%). SPECT revealed foci as small as 1.0 cm in the neck and 1.5 cm in the lungs, and was particularly useful in detection of disseminated micronodular pulmonary metastases, especially in patients whose scans were negative with diagnostic doses of 131I. Some pitfalls in interpretation of the tomographic reconstructions were found. Thallium-201 SPECT is a marked improvement over planar imaging in the detection of metastases of differentiated thyroid cancer.     

Pulmonary cryptococcosis: CT findings in immunocompetent patients

PURPOSE: To evaluate retrospectively the computed tomographic (CT) findings in immunocompetent patients with pulmonary cryptococcosis. MATERIALS AND METHODS: Institutional review board approval was obtained with a waiver of informed consent, and the study complied with requirements of the Health Insurance Portability and Accountability Act. Chest CT scans of 10 immunocompetent patients with clinically proved pulmonary cryptococcosis were retrospectively reviewed by four reviewers in consensus. Criterion for diagnosis of pulmonary cryptococcosis was (a) the histopathologic presence of the organism at lung biopsy or (b) a positive culture of a respiratory specimen or positive serum cryptococcal antigen test with clinical or radiographic evidence of active pulmonary infection. Patients included six women and four men ranging in age from 46 to 73 years (mean, 59 years). Scans were evaluated for nodules, masses, areas of ground-glass attenuation or of hazy increased attenuation, areas of consolidation, areas of cavitation, pleural effusions, linear opacities, septal thickening, lymphadenopathy, extent of parenchymal involvement, and distribution. RESULTS: The most common CT finding was pulmonary nodules (n = 9). Multiple nodules (n = 7) were more common than solitary nodules (n = 2). Nodules most commonly occupied less than 10% of the pulmonary parenchyma (n = 7), measured less than 10 mm in diameter (n = 7), and had middle and upper lung predominance (n = 6). The majority of the nodules were well defined with smooth margins (n = 7). Multiple nodules were usually bilaterally distributed (n = 5). Masses (n = 2), lymphadenopathy (n = 2), areas of consolidation (n = 2), areas of hazy increased attenuation (n = 1), pleural effusion (n = 1), and areas of cavitation (n = 1) were uncommon. CONCLUSION: CT most commonly demonstrated pulmonary nodules in immunocompetent patients with pulmonary cryptococcosis. The nodules were most often multiple, small, well defined, and smoothly marginated with middle and upper lung predominance.     

Screening for early lung cancer with low-dose spiral CT: prevalence in 817 asymptomatic smokers

PURPOSE: To present prevalence screening data from a nonrandomized screening trial by using low-dose computed tomography (CT) and a simple algorithm based on the size and attenuation of detected nodules to guide diagnostic work-up. MATERIALS AND METHODS: Eight hundred seventeen asymptomatic volunteers (age range, 40-78 years; median age, 53 years; median tobacco consumption, 45 pack-years) underwent spiral low-dose CT of the chest without contrast material enhancement. We regarded all noncalcified pulmonary nodules greater than 10 mm in diameter as potentially malignant and recommended histologic examination or follow-up after 3, 6, 12, and 24 months to exclude growth. For noncalcified pulmonary nodules of 10 mm or smaller, repeat low-dose CT was recommended to exclude growth. RESULTS: In 43% (350 of 817) of individuals, 858 noncalcified pulmonary nodules were found. Thirty-two nodules in 29 subjects were larger than 10 mm. Biopsy of 15 lesions revealed lung cancer in 12 lesions in 11 subjects (prevalence for all ages, 1.3% [11 of 817 subjects]; >50 years of age, 2.1% [11 of 519 subjects]; >60 years of age, 3.9% [eight of 206 subjects]), with a high proportion of early tumor stages (seven tumors, stage I; two, stage II; and three, stage III); three lesions were benign. In 17 nodules larger than 10 mm, follow-up with low-dose CT for a minimum of 24 months did not demonstrate growth. CONCLUSION: Lung cancer screening with low-dose CT demonstrated a prevalence of asymptomatic cancers in 1.3% of a smoking population, including a high proportion of early tumor stages and a 20% (three of 15) rate of invasive procedures for benign lesions.     

CT-guided transthoracic needle biopsy of pulmonary nodules smaller than 20 mm: results with an automated 20-gauge coaxial cutting needle

AIMS: To evaluate the efficacy and the complication rate of CT-guided percutaneous lung biopsy of pulmonary nodules smaller than 20 mm in diameter using a 20-gauge coaxial automated biopsy device. MATERIAL AND METHODS: A prospective study was undertaken of 200 patients who underwent 202 consecutive biopsies of pulmonary nodules, performed with a single type of automated biopsy device. Sixty-seven biopsies of nodules smaller than 20 mm in diameter were performed in 66 patients (group A). One hundred and thirty-five biopsies of lesions of 20 mm or greater in size were performed in 134 patients (group B). Patient characteristics, lesion and procedure variables, the accuracy and complication rates were compared. RESULTS: In group A, the final diagnosis of the nodules was malignant in 47 and benign in 19 cases (prevalence of malignancy 71. 2%). In group B, there were 111 malignant and 21 benign diagnoses (prevalence of malignancy 82.2%). In group A, the sensitivity and specificity for a diagnosis of malignancy were 89.5 and 100%, respectively (positive predictive value 100%, negative predictive value 76%). A specific diagnosis of benignity was obtained in nine out of 19 (47%) biopsies. The pneumothorax rate was 15% (10 patients) of which two (3%) required drainage. CT signs thought to reflect alveolar haemorrhage were noted in 28 (43%) and haemoptysis occurred in five patients (5.9%). In group B, the sensitivity and specificity for a diagnosis of malignancy were 95.5% and 100%, respectively (positive predictive value 100%, negative predictive value 82.7%). A specific diagnosis of benignity was made in 14 cases (58.3%). Complications included pneumothoraces in 22 cases (16.2%) requiring drainage in one (0.7%). Presumed alveolar haemorrhage was recorded in 19 cases (14.1%) and haemoptysis occurred in seven (5. 2%). There were no significant differences between group A and group B, except for alveolar haemorrhage (P < 0.001). CONCLUSION: The accuracy and complication rate of percutaneous CT-guided biopsy of nodules smaller than 20 mm, performed using an automated 20-gauge coaxial biopsy device, are comparable to those for larger lesions.     

Influence of increased 201Tl lung uptake on the myocardial viability of the patients with dilated cardiomyopathy under congestive heart failure]

Influence of increased 201Tl lung uptake on the myocardial viability was studied in 15 patients with dilated cardiomyopathy under congestive heart failure. Rest and 4 hours delayed 201Tl SPECT were obtained. At the same time anterior planar images were collected. In 10 patients of 15 patients 201Tl lung heart ratio in SPECT (LHR) was larger than that in planar images. Maximal 201Tl lung uptake was noted at the lower left lung adjacent to the heart. In the delayed images 201Tl lung uptake diminished. In 10 patients the value of LHR in the delayed images was less than 0.5. By comparing initial images with delayed images it was proved to be difficult to determine the myocardial margin adjacent to the increased 201Tl lung uptake. In 2 patients lateral defects were concealed by the increased 201Tl lung uptake. In the remaining patients lateral wall was similar to the hypertrophic myocardium. The effect of scatter due to the increased 201Tl lung uptake was noted in the neighboring myocardium. In most cases %201Tl uptake in the septum was relatively depressed by increased %201Tl uptake in the lateral wall. In the delayed images pseudo-redistribution was noted in the septum. Mean value of differences in %201Tl uptake between initial and delayed images was 8 (2-15)%. It was concluded that in case of increased 201Tl lung uptake SPECT could not accurately estimate myocardial viability by initial images and delayed images were necessary for precise estimation.