Search PubMed⌕ Search

Biomedical subjects

Stephen J Swensen

Publications and source records attributed to Stephen J Swensen.

At least 19 recordsLinked to original sources
PubMed2006

Characterization of the solitary pulmonary nodule: 18F-FDG PET versus nodule-enhancement CT.

OBJECTIVE: The purpose of this study was to directly compare nodule-enhancement CT and 18F-FDG PET in the characterization of indeterminate solitary pulmonary nodules (SPNs) greater than 7 mm in size. MATERIALS AND METHODS: Examinations from patients undergoing both nodule-enhancement CT and 18F-FDG PET to characterize the same indeterminate SPN were reviewed. For nodule-enhancement CT, an SPN was considered malignant when it showed an unenhanced to peak contrast-enhanced increase in attenuation greater than 15 H. Fluorine-18-FDG PET studies were blindly reinterpreted by two qualified nuclear radiologists. SPNs qualitatively showing hypermetabolic activity greater than the mediastinal blood pool were interpreted as malignant. These interpretations were compared with the original prospective clinical readings and to semiquantitative standardized uptake value (SUV) analysis. Results were compared with pathologic and clinical follow-up. RESULTS: Forty-two pulmonary nodules were examined. Twenty-five (60%) were malignant, and 17 (40%) were benign. Nodule-enhancement CT was positive in all 25 malignant nodules and in 12 benign nodules, with sensitivity and specificity of 100% and 29%, respectively, and with a positive predictive value (PPV) and negative predictive value (NPV) of 68% and 100%, respectively. Qualitative 18F-FDG PET interpretations were positive in 24 of the 25 malignant nodules and in four benign nodules. Fluorine-18-FDG PET was considered negative in one malignant nodule and in 13 of the 17 benign nodules. This correlates with a sensitivity and specificity of 96% and 76%, respectively, and with a PPV and NPV of 86% and 93%, respectively. Original prospective 18F-FDG PET and semiquantitative SUV analysis showed sensitivity, specificity, PPV, and NPV of 88%, 76%, 85%, and 81% and 84%, 82%, 88%, and 78%, respectively. CONCLUSION: Due to its much higher specificity and only slightly reduced sensitivity, 18F-FDG PET is preferable to nodule-enhancement CT in evaluating indeterminate pulmonary nodules. However, nodule-enhancement CT remains useful due to its high NPV, convenience, and lower cost. Qualitative 18F-FDG PET interpretation provided the best balance of sensitivity and specificity when compared with original prospective interpretation or SUV analysis.

Adult↗
PubMed2005

Relation between smoking cessation and receiving results from three annual spiral chest computed tomography scans for lung carcinoma screening.

BACKGROUND: The relation between undergoing a single computed tomography (CT) screening for lung carcinoma and the potential long-term impact on smoking status has been equivocal. Perhaps, recommendations from multiple cancer screenings may promote smoking abstinence among individuals at high risk for lung carcinoma. METHODS: The current longitudinal study comprised 926 current smokers and 594 former smokers who participated in 3 annual follow-up low-dose, fast spiral chest CT scan screenings for lung carcinoma. Baseline demographic, pulmonary function, smoking history variables, and previous abnormal findings were evaluated as predictors of self-reported point prevalence smoking abstinence. RESULTS: Among current smokers at baseline, abstinence from smoking during the 3-year follow-up was associated with older age, worse baseline pulmonary function, and abnormal CT finding the previous year requiring interim follow-up. Of participants who received abnormal screens each of the previous 3 years, 41.9% reported smoking abstinence compared with 28.0% with 2 abnormal screens, 24.2% with 1 abnormal screen, and 19.8% with no abnormal screens. Among former smokers, abstinence from smoking was associated with a longer duration of abstinence before the baseline visit. CONCLUSIONS: Smokers with abnormal CT findings from multiple CT screens were more likely to be abstinent from smoking at the 3-year follow-up. Multiple low-dose, fast spiral chest CT scan screenings for lung carcinoma may represent teachable moments and opportunities to enhance motivation for smoking abstinence. Further research is needed to continue to investigate how annual screening may enhance motivation for health behavior change.

Age Factors↗
PubMed2005

CT screening for lung cancer: five-year prospective experience.

PURPOSE: To report results of a 5-year prospective low-dose helical chest computed tomographic (CT) study of a cohort at high risk for lung cancer. MATERIALS AND METHODS: After informed written consent was obtained, 1520 individuals were enrolled. Protocol was approved by institutional review board and National Cancer Institute and was compliant with Health Insurance Portability and Accountability Act, or HIPAA. Participants were aged 50 years and older and had smoked for more than 20 pack-years. Participants underwent five annual (one initial and four subsequent) CT examinations. A significant downward shift was evaluated in non-small cell lung cancers detected initially from advanced stage down to stage I by using a one-sided binomial test of proportions. Poisson regression and Fisher exact tests were used for comparisons with Mayo Lung Project. RESULTS: In 788 (52%) men and 732 (48%) women, 61% (927 of 1520) were current smokers, and 39% were former smokers. After five annual CT examinations, 3356 uncalcified lung nodules were identified in 1118 (74%) participants. Sixty-eight lung cancers were diagnosed (31 initial, 34 subsequent, three interval cancers) in 66 participants. Twenty-eight subsequent cases of non-small cell cancers were detected, of which 17 (61%; 95% confidence interval: 41%, 79%) were stage I tumors. Diameter of cancers detected subsequently was 5-50 mm (mean, 14.4 mm; median, 10.0 mm). Analysis for a more than 50% shift in proportion of stage I non-small cell cancer detection did not show statistical significance. Forty-eight participants died of various causes since enrollment. Lung cancer mortality rate for incidence portion of trial was 1.6 per 1000 person-years. There was no significant difference in lung cancer mortality rates of cancers detected in subsequent examinations between this trial and Mayo Lung Project after separation of participants into subsets (2.8 vs 2.0 per 1000 person-years, P = .43). CONCLUSION: CT allows detection of early-stage lung cancers. Benign nodule detection rate is high. Results suggest no stage shift.

Aged↗
PubMed2005

Guidelines for management of small pulmonary nodules detected on CT scans: a statement from the Fleischner Society.

Lung nodules are detected very commonly on computed tomographic (CT) scans of the chest, and the ability to detect very small nodules improves with each new generation of CT scanner. In reported studies, up to 51% of smokers aged 50 years or older have pulmonary nodules on CT scans. However, the existing guidelines for follow-up and management of noncalcified nodules detected on nonscreening CT scans were developed before widespread use of multi-detector row CT and still indicate that every indeterminate nodule should be followed with serial CT for a minimum of 2 years. This policy, which requires large numbers of studies to be performed at considerable expense and with substantial radiation exposure for the affected population, has not proved to be beneficial or cost-effective. During the past 5 years, new information regarding prevalence, biologic characteristics, and growth rates of small lung cancers has become available; thus, the authors believe that the time-honored requirement to follow every small indeterminate nodule with serial CT should be revised. In this statement, which has been approved by the Fleischner Society, the pertinent data are reviewed, the authors' conclusions are summarized, and new guidelines are proposed for follow-up and management of small pulmonary nodules detected on CT scans.

Diagnosis, Differential↗
PubMed2005

Alpha1-antitrypsin and neutrophil elastase imbalance and lung cancer risk.

OBJECTIVE: Imbalance between alpha(1)-antitrypsin and neutrophil elastase is an underlying cause of lung tissue damage that may create a favorable host environment for carcinogenesis. We conducted a case-control study to investigate whether genetic variations indicative of alpha(1)-antitrypsin deficiency (A1ATD) or an excess of neutrophil elastase modify lung cancer risk DESIGN: The case patients were 305 consecutively identified primary lung cancer patients, and the control subjects were 338 community residents. Protease inhibitor-1 (PI1), encoding alpha(1)-antitrypsin, was typed by an isoelectric focusing assay. Neutrophil elastase-2 (ELA2), encoding neutrophil elastase, was typed by two single-nucleotide polymorphism sites. Multivariable logistic regression models tested the independent and interactive effects of PI1, ELA2, tobacco smoke exposure, COPD, and family history of lung cancer RESULTS: Sex and ethnicity were comparable between case patients and control subjects, but case patients were more likely to be smokers, and to have a history of COPD, environmental tobacco smoke exposure, and a positive family history of lung cancer. Haplotype analysis indicated an overall strong association between the two ELA2 markers and lung cancer risk. Our best-fitting model showed significant and independent effects of the PI1-deficient allele (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.4 to 3.0) and the ELA2 T-G haplotype (OR, 4.1; 95% CI, 1.9 to 8.9) on lung cancer risk, and an increased risk (OR, 2.6; 95% CI, 2.4 to 2.8) for individuals carrying both a PI1-deficient allele and a G-G haplotype CONCLUSIONS: Genotypes indicative of A1ATD and/or an excess of neutrophil elastase are significantly associated with lung cancer risk. Our findings may provide opportunities to better understand the mechanisms of lung cancer development and risk reduction.

Aged↗
PubMed2005

Lung cancer screening experience: a retrospective review of PET in 22 non-small cell lung carcinomas detected on screening chest CT in a high-risk population.

OBJECTIVE: The objective of our study was to retrospectively review the PET results of non-small cell lung carcinomas detected on screening chest CT in a high-risk population. CONCLUSION: PET findings were negative in 32% of the cases of non-small cell carcinomas that were detected on screening CT in a high-risk patient population. These tumors were small, low-grade, or both. The most common histology was bronchioloalveolar cell carcinoma. The role of PET in evaluating screening-detected indeterminate nodules in a high-risk population may be more limited than in a general population.

Carcinoma, Non-Small-Cell Lung↗
PubMed2005

Optimizing weekend availability for sophisticated tests and procedures in a large hospital.

The reduced availability of sophisticated tests and procedures in hospitals on weekends (the so-called "weekend effect") delays care. Addressing this problem requires hospital managers to balance the desire for timeliness with the need for efficient operations. We illustrate how a hospital can profile timeliness, demand, and capacity utilization across the week for multiple testing areas. This simple, practical method; using data extracted from the hospital's accounting system, makes visible the pattern and magnitude of delays caused by reduced availability on weekends, while also showing how capacity is deployed. We combined the analytical tool with a process of transparent feedback and local problem solving that engages multiple stakeholders in the hospital. The goal is to optimally configure capacity so as to balance the imperatives of timely availability and efficient resource utilization.

Diagnostic Tests, Routine↗
PubMed2004

Estimate of lung cancer mortality from low-dose spiral computed tomography screening trials: implications for current mass screening recommendations.

PURPOSE: Low-dose computed tomography (CT) has been suggested for lung cancer screening. Several observational trials have published their preliminary results, and some investigators suggest that this technique will save lives. There are no mortality statistics, however, and the current study used published data from these trials to estimate the disease-specific mortality in this high-risk population. PATIENTS AND METHODS: Two nonrandomized CT screening trials were selected from the literature for analysis. The number of trial participants, the number of lung cancers diagnosed per year, and stage distribution of the cancers was recorded. Previously published 5-year survival data were used to calculate the number of predicted lung cancer deaths and estimate the overall lung cancer mortality per 1,000 person-years among participants screened. These statistics were then compared to the previous Mayo Lung Project, which used chest radiographs and sputum cytology for screening high-risk individuals. RESULTS: This study estimates the lung cancer mortality is 4.1 deaths per 1,000 person-years in the Mayo Clinic CT screening trial, and is 5.5 deaths per 1,000 person-years in the Early Lung Cancer Action Program trial. These data are similar to the lung cancer mortality of 4.4 deaths per 1,000 person-years in the interventional arm, and 3.9 deaths per 1,000 person-years in the usual-care arm of the previous Mayo Lung Project. CONCLUSION: These data suggest that CT screening could produce similar outcomes to prior chest radiographic trials in this high-risk group. Results from randomized trials are required, however, before the true utility of mass screening with CT for lung cancer can be determined.

Aged↗
PubMed2004

Thoracic surgical operations in patients enrolled in a computed tomographic screening trial.

OBJECTIVE: Screening for lung cancer with computed tomography may detect cancers at an earlier stage but may also result in overdiagnosis. We reviewed the thoracic surgical operations performed on patients enrolled in our computed tomographic screening program. METHODS: From January 1999 through December 2002, screening computed tomography for lung cancer was performed annually on 1520 participants. All participants were at least 50 years old and smoked more than 20 pack/y. We found 3130 indeterminate pulmonary nodules in 1112 participants (73%). Fifty-five participants (3.6%) underwent 60 thoracic operations for a variety of indications. The medical records of these 55 patients were reviewed. RESULTS: Indications for operation included suspicious pulmonary nodules, mediastinal adenopathy, and a spontaneous pneumothorax. Operations performed included a lobectomy in 37 cases, wedge resection in 11, segmentectomy in 6, video-assisted thoracoscopic surgical talc pleurodesis in 1, bilobectomy in 2, mediastinoscopy in 2, and anterior mediastinotomy in 1. Benign disease was found in 10 patients (18.1%), and lung cancer was found in 45 (81.9%), 2 of whom had metachronous lung cancers. Cell types were adenocarcinoma in 15 cancers, bronchioloalveolar cell carcinoma in 13, squamous cell in 13, carcinoid in 2, small cell in 2, and large cell and undifferentiated non-small cell in 1 case each. Twenty-eight cancers were classified as stage IA, 4 as IB, 4 as IIA, 1 as IIB, 4 as IIIA, 3 as IIIB, 1 as IV, and 2 as limited small cell carcinoma. Complications occurred in 27% of patients. Operative mortality was 1.7%. CONCLUSION: Computed tomographic screening finds a large number of indeterminate pulmonary nodules in smokers 50 years old or older, most of which are observed and not operated on. Although 47 cancers were detected thus far in this highly selected group of patients, this represents only 1.5% of the pulmonary nodules identified.

Aged↗
PubMed2004

Effectiveness of smoking cessation self-help materials in a lung cancer screening population.

Randomized controlled trials of smoking interventions have not been well-documented for lung cancer screening populations. In this study, we randomly assigned 171 current smokers who were undergoing low-dose fast spiral chest CT (SCTS) for lung cancer screening to receive either standard written self-help materials or a written list of Internet resources for smoking cessation. At the 1-year follow-up, more of the subjects receiving Internet-based resources reported making a stop attempt (68% versus 48%, P=0.011). However, there were no statistically significant differences in 7-day point prevalence quit rates (5% versus 10%) or advancement in motivational readiness to stop smoking (27% versus 30%), respectively, between the groups. Clearly, more investigation is warranted into how to tailor smoking interventions for cancer screening participants.

Aged↗
PubMed2004

Sensitivity and specificity of the semiquantitative latex agglutination D-dimer assay for the diagnosis of acute pulmonary embolism as defined by computed tomographic angiography.

OBJECTIVE: To determine the sensitivity and specificity of the semiquantitative latex agglutination plasma fibrin D-dimer assay for the diagnosis of acute pulmonary embolism by using computed tomographic (CT) angiography as the diagnostic reference standard. PATIENTS AND METHODS: From January 1, 1998, to June 26, 2000, patients who had both semiquantitative latex agglutination plasma fibrin D-dimer testing and CT angiography for suspected acute pulmonary embolism were selected for the study. A D-dimer value greater than 250 ng/mL was considered positive for thromboembolic disease. Diagnosis of acute pulmonary embolism was based solely on the interpretation of the CT angiogram. The D-dimer assay results were then compared with the CT angiographic diagnoses. RESULTS: Of 946 CT studies, 172 (18%) were positive for acute pulmonary embolism. The D-dimer assay was positive for 612 (65%) of the 946 patients. For acute pulmonary embolism, the D-dimer assay had a sensitivity of 0.83 (95% confidence interval [CI], 0.76-0.88), a specificity of 039 (95% CI, 036-0.43), a negative likelihood ratio of 0.44 (95 % CI, 032-0.62), and a negative predictive value of 0.91 (95% CI, 0.87-0.94). CONCLUSIONS: The semiquantitative latex agglutination plasma fibrin D-dimer assay had moderate sensitivity and low specificity for the diagnosis of acute pulmonary embolism. When used alone, the results of this test were insufficient to exclude this serious and potentially fatal disorder. Approximately two thirds of our patients had positive D-dimer assays and required further evaluation to exclude acute pulmonary embolism.

Adolescent↗
PubMed2004

Clinicoradiological features of pulmonary infarctions mimicking lung cancer.

OBJECTIVE: To describe presenting features of pulmonary infarction that may simulate those of lung cancer. PATIENTS AND METHODS: We reviewed the medical records of 43 patients with pulmonary infarction diagnosed by surgical lung biopsy at the Mayo Clinic in Rochester, Minn, from January 1, 1996, to December 31, 2002. Of 16 patients presenting with an undiagnosed solitary pulmonary nodule or mass, 6 had features suggestive of lung cancer on additional imaging, including abnormalities on contrast-enhancement computed tomography (CT), positron emission tomography (PET), or nonsurgical lung biopsy before surgical resection. We examined the presenting symptoms, epidemiological, clinical, and radiological features, and clinical course of these 6 patients. RESULTS: All 6 patients, ranging in age from 41 to 85 years, had a history of smoking and underlying cardiopulmonary disease. In 5 of the 6 patients, CT showed a nodule in the subpleural region of the lung. Three patients had abnormalities on contrast-enhancement CT, 2 had abnormalities on PET, and 1 had abnormal cytologic findings on a transthoracic needle biopsy of the lung; all these studies showed abnormalities suggestive of lung cancer. Surgical resection of the nodule or mass revealed pulmonary infarction associated with organizing thrombi in all 6 patients. CONCLUSIONS: Pulmonary infarctions can closely mimic the clinicoradiological characteristics of lung cancer, an association not reported previously. Furthermore, cytologic changes that occur in pulmonary infarctions may produce malignant-appearing cells on needle biopsy of the lung. The possibility of pulmonary infarction should be considered in the differential diagnosis of a solitary lung nodule or mass located in the subpleural region, even in the absence of clinically recognized venous thromboembolism.

Adult↗
PubMed2003

Change in smoking status after spiral chest computed tomography scan screening.

BACKGROUND: Cancer screening may provide a "teachable moment" for the reduction of high-risk behaviors. The current study evaluated smoking behavior changes in current and former smokers after low-dose, fast spiral chest computed tomography scan (CT) screening for lung carcinoma. METHODS: The study was comprised of 901 current smokers and 574 former smokers who participated in a low-dose, fast spiral chest CT scan screening study for lung carcinoma. Demographic, pulmonary function, screening recommendations, and smoking history variables were evaluated as predictors of self-reported point prevalence smoking abstinence 1 year after screening. RESULTS: Of the current smokers at baseline, 14% reported smoking abstinence at follow-up. Older age and poorer lung function were associated with smoking abstinence. Ninety percent of former smokers reported smoking abstinence at a 1-year of follow-up. A longer duration of smoking abstinence at baseline was found to be predictive of abstinence in this group. CONCLUSIONS: The 14% smoking abstinence rate was higher than would be expected for spontaneous rates of smoking cessation. Therefore, screening may provide a teachable moment for smokers. Low-dose, fast spiral chest CT scan screening recommendations were not found to be associated with smoking behavior change in either group. Further research is needed to evaluate the potential avenues through which lung carcinoma screening can be used as an opportunity for providing effective nicotine interventions.

Age Factors↗
PubMed2003

Bronchiolar disorders.

Bronchiolar abnormalities are relatively common and occur in a variety of clinical settings. Various histopathologic patterns of bronchiolar injury have been described and have led to confusing nomenclature with redundant and overlapping terms. Some histopathologic patterns of bronchiolar disease may be relatively unique to a specific clinical context but others are nonspecific with respect to either etiology or pathogenesis. Herein, we present a scheme separating (1) those disorders in which the bronchiolar disease is the predominant abnormality (primary bronchiolar disorders) from (2) parenchymal disorders with prominent bronchiolar involvement and (3) bronchiolar involvement in large airway diseases. Primary bronchiolar disorders include constrictive bronchiolitis (obliterative bronchiolitis, bronchiolitis obliterans), acute bronchiolitis, diffuse panbronchiolitis, respiratory bronchiolitis, mineral dust airway disease, follicular bronchiolitis, and a few other rare variants. Prominent bronchiolar involvement may be seen in several interstitial lung diseases, including hypersensitivity pneumonitis, respiratory bronchiolitis-associated interstitial lung disease, cryptogenic organizing pneumonia (idiopathic bronchiolitis obliterans organizing pneumonia), and pulmonary Langerhans' cell histiocytosis. Large airway diseases that commonly involve bronchioles include bronchiectasis, asthma, and chronic obstructive pulmonary disease. The clinical relevance of a bronchiolar lesion is best determined by identifying the underlying histopathologic pattern and assessing the correlative clinico-physiologic-radiologic context.

Bronchi↗
PubMed2003

Lung cancer screening with CT: Mayo Clinic experience.

PURPOSE: To evaluate a large cohort of patients at high risk for lung cancer by using screening with low-dose spiral computed tomography (CT) of the chest. MATERIALS AND METHODS: A prospective cohort study was performed with 1,520 individuals aged 50 years or older who had smoked 20 pack-years or more. Participants underwent three annual low-dose CT examinations of the chest and upper abdomen. Characteristics of pulmonary nodules and additional findings were tabulated and analyzed. RESULTS: Two years after baseline CT scanning, 2,832 uncalcified pulmonary nodules were identified in 1,049 participants (69%). Forty cases of lung cancer were diagnosed: 26 at baseline (prevalence) CT examinations and 10 at subsequent annual (incidence) CT examinations. CT alone depicted 36 cases; sputum cytologic examination alone, two. There were two interval cancers. Cell types were as follows: squamous cell tumor, seven; adenocarcinoma or bronchioloalveolar carcinoma, 24; large cell tumor, two; non-small cell tumor, three; small cell tumor, four. The mean size of the non-small cell cancers detected at CT was 15.0 mm. The stages were as follows: IA, 22; IB, three; IIA, four; IIB, one; IIIA, five; IV, one; limited small cell tumor, four. Twenty-one (60%) of the 35 non-small cell cancers detected at CT were stage IA at diagnosis. Six hundred ninety-six additional findings of clinical importance were identified. CONCLUSION: CT can depict early-stage lung cancers. The rate of benign nodule detection is high.

Aged↗