Preoperative Helical Dynamic Enhanced Multidetector Row Computed Tomography: Can It Be a Prognostic Indicator in Early-Stage Non-small Cell Lung Cancer?

OBJECTIVE: This study aimed to investigate the prognostic significance of dynamic contrast-enhanced computed tomography in patients with stage IA non-small cell lung cancer (NSCLC). METHODS: We retrospectively enrolled 139 patients (77 men, 62 women; mean age, 59 years) with stage IA NSCLC who underwent dynamic contrast-enhanced computed tomography. Data on age, pathologic subtype, peak enhancement, and net enhancement of primary lung cancer were collected and correlated with 5-year survival. RESULTS: Peak enhancement had a significant correlation with overall survival in the univariable analysis (hazard ratio [HR], 1.18, confidence interval [CI], 1.01-1.38; P = 0.04) and in the multivariable analysis (HR, 1.19; CI, 1.01-1.39; P = 0.04). Patients with peak enhancement of 90 Hounsfield unit or higher had a significantly increased risk of death compared with patients with less enhancement after curative surgery (HR, 4.15; CI, 1.23-13.95; P = 0.02). CONCLUSIONS: Our study confirmed the prognostic significance of peak enhancement as an indicator for the overall survival of stage IA NSCLC.

Low-dose CT screening in an Asian population with diverse risk for lung cancer: A retrospective cohort study.

OBJECTIVES: To evaluate the performance of low-dose CT (LDCT) screening for lung cancer (LCA) detection in an Asian population with diverse risks for LCA. MATERIALS AND METHODS: LCA screening was performed in 12,427 symptomless Asian subjects using either LDCT (5,771) or chest radiography (CXR) (6,656) in a non-trial setting. Subjects were divided into high-risk and non-high-risk groups. Data were collected on the number of patients with screening-detected LCAs and their survival in order to compare outcomes between LDCT and CXR screening with the stratification of risks considering age, sex and smoking status. RESULTS: In the non-high-risk group, a significant difference was observed for the detection of lung cancer (adjusted OR, 5.07; 95 % CI, 2.72-9.45) and survival (adjusted HR of LCA survival between LDCT vs. CXR group, 0.08; 95 % CI, 0.01-0.62). No difference in detection or survival of LCA was noticed in the high-risk group. LCAs in the non-high-risk group were predominantly adenocarcinomas (96 %), and more likely to be part-solid or non-solid compared with those in the high-risk group (p = 0.023). CONCLUSIONS: In the non-high-risk group, LDCT helps detect more LCAs and offers better survival than CXR screening, due to better detection of part solid or non-solid lung adenocarcinomas. KEY POINTS: • In an Asian non-high-risk group, LDCT helps detect more early-staged LCAs. • CT-detected lung cancers in non-high-risk subjects demonstrate better survival than CXR-detected cancers. • CT-detected lung cancers in non-high-risk subjects are predominantly part-solid or non-solid adenocarcinomas. • Mortality benefit of LDCT screening in non-high-risk subjects needs to be investigated.

Diffusion-weighted MRI for distinguishing non-neoplastic cysts from solid masses in the mediastinum: problem-solving in mediastinal masses of indeterminate internal characteristics on CT.

OBJECTIVES: To evaluate the usefulness of diffusion-weighted (DW) magnetic resonance images for distinguishing non-neoplastic cysts from solid masses of indeterminate internal characteristics on computed tomography (CT) in the mediastinum. METHODS: We enrolled 25 patients with pathologically proved mediastinal masses who underwent both thoracic CT and magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI). MRI was performed in patients with mediastinal masses of indeterminate internal characteristics on CT. Two thoracic radiologists evaluated the morphological features and quantitatively measured the net enhancement of the masses at CT. They also reviewed MR images including unenhanced T1- and T2-weighted images, gadolinium-enhanced images and DW images. RESULTS: The enrolled patients had 15 solid masses and ten non-neoplastic cysts. Although the morphological features and the extent of enhancement on CT did not differ significantly between solid and cystic masses in the mediastinum (P > 0.05), non-neoplastic cysts were distinguishable from solid masses by showing signal suppression on high-b-value DW images or high apparent diffusion coefficient (ADC) values of more than 2.5 × 10(-3) mm(2)/s (P < 0.001). ADC values of non-neoplastic cysts (3.67 ± 0.87 × 10(-3) mm(2)/s) were significantly higher than that of solid masses (1.46 ± 0.50 × 10(-3) mm(2)/s) (P < 0.001). CONCLUSIONS: DWI can help differentiate solid and cystic masses in the mediastinum, even when CT findings are questionable. KEY POINTS: • Non-invasive diagnosis of non-neoplastic cysts can save surgical biopsy or excision. • Conventional CT or MRI findings cannot always provide a confident diagnosis. • Mediastinal masses can be well-characterised with DWI. • Non-neoplastic mediastinal cysts show significantly higher ADC values than cystic tumours. • DWI is useful to determine treatment strategy.

Subcentimeter lung nodules stable for 2 years at LDCT: long-term follow-up using volumetry.

BACKGROUND AND OBJECTIVE: Subcentimeter nodules without change in size during long-term follow-up period (for minimum 2 years) are assumed as benign lesions. However, the 2-year stability rule has not been fully verified so far and is still questionable. Thus, we aimed to retrospectively investigate long-term follow-up results for 2-year stable subcentimeter nodules at screening low-dose computed tomography (LDCT). METHODS: A total of 635 subjects having had follow-up LDCTs for the initial 2-year screening period and additional 3 years thereafter and having had non-calcified subcentimeter nodules were included. By using computed tomography (CT) nodule volumetry software, we measured interval changes in nodule volume. RESULTS: A total of 1107 subcentimeter nodules (1037 solid, 70 ground-glass opacity nodules (GGNs)) were detected at baseline CT. Of 1037 solid nodules, 1032 showed no growth during the initial 2-year and 5-year follow-up period. Fifty-nine GGNs were stable for initial 2 years, but two (3.4%) were later proved as adenocarcinomas. Among five solid nodules that showed growth during the initial 2-year follow-up period, one (20%) proved to be an adenocarcinoma, whereas four (36.4%) of 11 GGNs that demonstrated growth were diagnosed as lung cancers. CONCLUSIONS: All solid subcentimeter nodules having initial 2-year stability at screening LDCT can be considered benign because none shows growth at further follow-up CT. On the other hand, subcentimeter GGNs have more chance of growth than solid nodules and need further follow-up CT for more than 2 years.

Coregistered whole body magnetic resonance imaging-positron emission tomography (MRI-PET) versus PET-computed tomography plus brain MRI in staging resectable lung cancer: comparisons of clinical effectiveness in a randomized trial.

BACKGROUND: The objective of this study was to assess whether coregistered whole brain (WB) magnetic resonance imaging-positron emission tomography (MRI-PET) would increase the number of correctly upstaged patients compared with WB PET-computed tomography (PET-CT) plus dedicated brain MRI in patients with nonsmall cell lung cancer (NSCLC). METHODS: From January 2010 through November 2011, patients with NSCLC who had resectable disease based on conventional staging were assigned randomly either to coregistered MRI-PET or WB PET-CT plus brain MRI (ClinicalTrials.gov trial NCT01065415). The primary endpoint was correct upstaging (the identification of lesions with higher tumor, lymph node, or metastasis classification, verified with biopsy or other diagnostic test) to have the advantage of avoiding unnecessary thoracotomy, to determine appropriate treatment, and to accurately predict patient prognosis. The secondary endpoints were over staging and under staging compared with pathologic staging. RESULTS: Lung cancer was correctly upstaged in 37 of 143 patients (25.9%) in the MRI-PET group and in 26 of 120 patients (21.7%) in the PET-CT plus brain MRI group (4.2% difference; 95% confidence interval, -6.1% to 14.5%; P = .426). Lung cancer was over staged in 26 of 143 patients (18.2%) in the MRI-PET group and in 7 of 120 patients (5.8%) in the PET-CT plus brain MRI group (12.4% difference; 95% confidence interval, 4.8%-20%; P = .003), whereas lung cancer was under staged in 18 of 143 patients (12.6%) and in 28 of 120 patients (23.3%), respectively (-10.7% difference; 95% confidence interval, -20.1% to -1.4%; P = .022). CONCLUSIONS: Although both staging tools allowed greater than 20% correct upstaging compared with conventional staging methods, coregistered MRI-PET did not appear to help identify significantly more correctly upstaged patients than PET-CT plus brain MRI in patients with NSCLC.

Histopathology of lung adenocarcinoma based on new IASLC/ATS/ERS classification: prognostic stratification with functional and metabolic imaging biomarkers.

PURPOSE: To correlate the results of histopathologic subtyping and grading of lung adenocarcinoma with maximum standardized uptake values (SUVmax) on positron emission tomography (PET)/computed tomography and apparent diffusion coefficient (ADC) values on diffusion-weighted MRI (DWI). MATERIALS AND METHODS: Forty-three patients were included. The SUVmax and mean ADC values of tumors were measured and correlated with the histologic subtypes and grades of lung adenocarcinomas based on the IASLC/ATS/ERS classification scheme. Disease-free survival (DFS) was estimated by using the Kaplan-Meier method, and the log-rank test was used to evaluate differences among three histologic grades or subgroups classified with imaging biomarker study results. RESULTS: Five (12.5%) tumors belonged to low grade, 30 (70%) to intermediate grade, and 8 (18.5%) to high grade, and patients with low-grade histology had lower risk of recurrence than those with intermediate- or high-grade histology (P = 0.048). A significant difference in SUVmax and mean ADC values was observed among three histologic grades (Ps < 0.001). Regarding DFS, lower metabolic (PET) activity or higher functional (DWI) diffusivity showed longer DFS. When patients (n = 30; 70% of patients) with intermediate histologic grade were subgrouped in consideration of both SUVmax and mean ADC results, combining metabolic and functional criteria helped stratify patients more precisely (P = 0.006). CONCLUSION: SUVmax and mean ADC value correlate well with the histologic grades in lung adenocarcinomas, and combining both imaging biomarker study results leads to more useful stratification of patients into different prognostic subsets than the results of each study.

A case of acute pulmonary embolism associated with dysplasminogenemia.

The incidence of pulmonary embolism (PE) rises markedly with age, and only a few cases have been reported in younger adults. Thrombophilia has been reported as one of the predisposing factors for PE in younger adults. Here we report an extraordinary case of PE complicated with dysplasminogenemia, a rare genetic disorder resulting in hypercoagulability, in a young male. An 18-yr-old male visited an emergency room in the United States complaining chest discomfort. He was diagnosed as PE with deep vein thrombosis without apparent risk factors. Anticoagulation therapy with warfarin had been initiated and discontinued after 6 months of treatment. After returning to Korea he was tested for thrombophilia which revealed decreased activity of plasminogen and subsequent analysis of PLG gene showed heterozygous Ala620Thr mutation. He was diagnosed with PE complicated with dysplasminogenemia. Life-long anticoagulation therapy was initiated. He is currently under follow-up without clinical events for 2 yr.

Predicting Non-Small-Cell Lung Cancer Survival after Curative Surgery via Deep Learning of Diffusion MRI.

BACKGROUND: the objective of this study is to evaluate the predictive power of the survival model using deep learning of diffusion-weighted images (DWI) in patients with non-small-cell lung cancer (NSCLC). METHODS: DWI at b-values of 0, 100, and 700 sec/mm2 (DWI0, DWI100, DWI700) were preoperatively obtained for 100 NSCLC patients who underwent curative surgery (57 men, 43 women; mean age, 62 years). The ADC0-100 (perfusion-sensitive ADC), ADC100-700 (perfusion-insensitive ADC), ADC0-100-700, and demographic features were collected as input data and 5-year survival was collected as output data. Our survival model adopted transfer learning from a pre-trained VGG-16 network, whereby the softmax layer was replaced with the binary classification layer for the prediction of 5-year survival. Three channels of input data were selected in combination out of DWIs and ADC images and their accuracies and AUCs were compared for the best performance during 10-fold cross validation. RESULTS: 66 patients survived, and 34 patients died. The predictive performance was the best in the following combination: DWI0-ADC0-100-ADC0-100-700 (accuracy: 92%; AUC: 0.904). This was followed by DWI0-DWI700-ADC0-100-700, DWI0-DWI100-DWI700, and DWI0-DWI0-DWI0 (accuracy: 91%, 81%, 76%; AUC: 0.889, 0.763, 0.711, respectively). Survival prediction models trained with ADC performed significantly better than the one trained with DWI only (p-values < 0.05). The survival prediction was improved when demographic features were added to the model with only DWIs, but the benefit of clinical information was not prominent when added to the best performing model using both DWI and ADC. CONCLUSIONS: Deep learning may play a role in the survival prediction of lung cancer. The performance of learning can be enhanced by inputting precedented, proven functional parameters of the ADC instead of the original data of DWIs only.

Repeat biopsy for mutational analysis of non-small cell lung cancers resistant to previous chemotherapy: adequacy and complications.

PURPOSE: To evaluate the feasibility and safety of repeat biopsy for mutational analysis in patients with non-small cell lung cancer (NSCLC) who have a resistance history to previous chemotherapy. MATERIALS AND METHODS: This prospective study was institutional review board approved, and written informed consent was obtained from all patients. Of 126 patients referred for repeat biopsy (hereafter, rebiopsy) with NSCLC that was resistant to conventional chemotherapy or epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors, 94 patients (31 men, 63 women; mean age ± standard deviation, 57 years ± 10.3) were selected for rebiopsy. Thirty-two patients were excluded for several reasons after strict review of the chest computed tomography (CT) images. Percutaneous transthoracic lung biopsy was performed with C-arm cone-beam CT guidance. The technical success rates for the rebiopsy and the adequacy rates of specimens for mutational analysis were evaluated. Any biopsy-related complications were recorded. RESULTS: The technical success rate for biopsy was 100%. In 75 (80%) of 94 patients, specimens were adequate for mutational analysis. Of 75 specimens, 35 were tested for EGFR mutation, 34 for anaplastic lymphoma kinase gene (ALK) rearrangement, and six for both. The results were positive for EGFR-sensitizing mutation (exon 19 or 21) in 20, for EGFR T790M mutation in five, and for ALK rearrangement in 11. Postprocedural complications occurred in 13 (14%) of 94 patients. CONCLUSION: When performed by employing rigorous CT criteria, rebiopsies for the mutational analysis of NSCLCs treated previously with chemotherapy are feasible in all patients and are adequate in approximately four-fifths of patients referred for gene analysis, with acceptable rates of complications.

A proposal for combined MRI and PET/CT interpretation criteria for preoperative nodal staging in non-small-cell lung cancer.

OBJECTIVES: To determine the positive reading criteria for malignant nodes when interpreting combined MRI and PET/CT images for preoperative nodal staging in non-small-cell lung cancer (NSCLC). METHODS: Forty-nine patients with biopsy-proven NSCLC underwent both PET/CT and thoracic MRI [diffusion weighted imaging (DWI)]. Each nodal station was evaluated for the presence of metastasis by applying either inclusive (positive if either one read positive) or exclusive (positive if both read positive) criteria in the combined interpretation of PET/CT and MRI. Nodal stage was confirmed pathologically. The combined diagnostic accuracy of PET/CT and MRI was determined on per-nodal station and per-patient bases and compared with that of PET/CT alone. RESULTS: In 49 patients, 39 (19%) of 206 nodal stations harboured malignant cells. Out of 206 nodal stations, 186 (90%) had concordant readings, while the rest (10%) had discordant readings. Inclusive criteria of combined PET/CT and MRI helped increase sensitivity for detecting nodal metastasis (69%) compared with PET/CT alone (46%; P = 0.003), while specificity was not significantly decreased. CONCLUSION: Inclusive criteria in combined MRI and PET/CT readings help improve significantly the sensitivity for detecting nodal metastasis compared with PET/CT alone and may decrease unnecessary open thoracotomy. Key Points • Combined interpretation of MRI and PET/CT enhances the detection of nodal metastasis. • Inclusive criteria of combined MRI/PET/CT improved the sensitivity for detecting nodal metastasis. • Combined interpretation of MRI and PET/CT may reduce unnecessary open thoracotomies.

CT findings of late-onset noninfectious pulmonary complications in patients with pathologically proven graft-versus-host disease after allogeneic stem cell transplant.

OBJECTIVE: We retrospectively analyzed the CT features of late-onset noninfectious pulmonary complications in patients with pathologically proven graft-versus-host disease (GVHD) after allogeneic stem cell transplant (SCT). MATERIALS AND METHODS: We analyzed the CT features of late-onset noninfectious pulmonary complications in 14 patients with pathologic diagnoses of GVHD who survived disease free for more than 3 months after SCT. Late-onset noninfectious pulmonary complications were diagnosed by excluding pulmonary infection in these patients with respiratory symptoms and signs. The presence, extent, and distribution of CT features were evaluated in terms of geographic hypoattenuation, expiratory airtrapping, ground-glass attenuation (GGA), reticulation, crazy paving pattern, bronchiectasis, nodules, and honeycombing. Further disease classification was made on the basis of clinical, radiologic, and pulmonary function test results and histologic findings. The longitudinal changes of late-onset noninfectious pulmonary complications were followed with CT. RESULTS: The 14 patients with late-onset noninfectious pulmonary complications were classified into subgroups with bronchiolitis obliterans (BO) (n = 7), nonclassifiable interstitial pneumonia (n = 5), and combined BO and nonclassifiable interstitial pneumonia (n = 2). The CT features of nonclassifiable interstitial pneumonia were GGA (5/7, 71%), reticulation (4/7, 57%), and crazy paving pattern (4/7, 57%) with a peribronchovascular distribution (6/7, 86%). All patients with nonclassifiable interstitial pneumonia had progression of disease with an increased extent of traction bronchiectasis, reticulation, and honeycombing on follow-up CT scans (median follow-up period, 22 months). CONCLUSION: Although not commonly encountered, nonclassifiable interstitial pneumonia as a pattern of chronic GVHD should be included in the differential diagnosis of unexplained peribronchial GGA or progressive traction bronchiectasis after SCT.

Lung metastases in metastatic gastric cancer: pattern of lung metastases and clinical outcome.

BACKGROUND: There are only limited data regarding pulmonary metastasis from gastric cancer. Therefore, we analyzed large series of gastric cancer with pulmonary metastasis and analyzed their clinical characteristics and treatment outcome to enhance perception of metastatic gastric cancer. METHODS: Of 20,187 advanced gastric cancer patients treated between 1995 and 2007, 193 (0.96%) were identified to have pulmonary metastasis from gastric cancer. The pulmonary lesions were detected at chest computed tomography (CT) scan or plain chest X-ray and/or abdominal pelvic CT scan covering the lower part of the lungs, and were divided into three patterns: lymphangitic, hematogenous, and pleural. RESULTS: The most frequently observed pattern of lung metastasis was hematogenous metastasis (52.3%) followed by pleural (35.2%) and lymphangitic (26.4%). Patients who had hematogenous pulmonary metastasis were significantly associated with hepatic metastasis (p = 0.004) and male sex (p = 0.012). Patients with lymphangitic metastasis were significantly associated with concomitant bone (p = 0.010) and bone marrow (p = 0.029) metastasis. In case of pleural metastasis, it was positively correlated with gastrectomy history (p = 0.015) and the presence of peritoneal metastasis (p = 0.020). After a median follow-up duration of 87 (9-162) months, the median survival after diagnosis of pulmonary metastasis was 4 (0-67) months. CONCLUSION: The most frequently observed pattern of lung metastasis was hematogenous metastasis (52.3%) followed by pleural (35.2%) and lymphangitic (26.4%) in gastric cancer patients. Among gastric cancer patients with lung metastases, patients with pleural metastasis or lymphangitic metastasis had shorter survival with 1.5-2-fold increased risk of deaths.

Dynamic contrast-enhanced MRI for response evaluation of non-small cell lung cancer in therapy with epidermal growth factor receptor tyrosine kinase inhibitors: a pilot study.

BACKGROUND: It is important to identify candidates who would benefit from target agent chemotherapy in advanced NSCLC patients. The purpose of this study is to evaluate the feasibility of DCE-MRI for early response evaluation in epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) treatment in patients with NSCLC. METHODS: Seven patients were prospectively enrolled who have pathologically-proven NSCLC with EGFR mutations or at least 2 of the following factors; adenocarcinoma, female, or never-smokers. Patients were treated with gefitinib or erlotinib and the start of chemotherapy was denoted day 0. DCE-MRI was performed at day-1, day+7, and day+28. Longitudinal changes of perfusion parameters were quantified and compared to Response Evaluation Criteria in Solid Tumors (RECIST) results. RESULTS: Quantitative perfusion parameters; Ktrans, ve and vp of the lung cancer showed a significant decrease at day+7 (P=0.016), but no further significant decrease between day+7 and day+28 (P>0.05). Semiquantitative markers for tumor enhancement curve pattern; EA (enhancement amplitude), MS (maximum slope), and AUC (area under the curve) also showed a significant decrease at day+7 (P=0.016, 0.031, and 0.016, respectively), but no further significant decrease between day+7 and day+28 (P>0.05). When RECIST applied, all patient was in the stable disease at day+7 and three patients showed partial response (PR) at day+28. All seven patients showed PR by the 3-month follow-up. CONCLUSIONS: Perfusion parameters may be used as an early non-invasive imaging biomarker for the response evaluation of target agent treatment in NSCLC.

Imaging of pulmonary vasculitis.

The presence of pulmonary vasculitis can be suggested by a clinical presentation that includes diffuse pulmonary hemorrhage, acute glomerulonephritis, chronic refractory sinusitis or rhinorrhea, imaging findings of nodules or cavities, mononeuritis multiplex, multisystemic disease, and palpable purpura. Serologic tests, including the use of cytoplasmic antineutrophil cytoplasmic antibody (ANCA) and perinuclear ANCA, are performed for the differential diagnosis of the diseases. A positive cytoplasmic ANCA test result is specific enough to make a diagnosis of ANCA-associated granulomatous vasculitis if the clinical features are typical. Perinuclear ANCA positivity raises the possibility of Churg-Strauss syndrome or microscopic polyangiitis. Imaging findings of pulmonary vasculitis are diverse and often poorly specific. The use of a pattern-based approach to the imaging findings may help narrow the differential diagnosis of various pulmonary vasculitides. Integration of clinical, laboratory, and imaging findings is mandatory for making a reasonably specific diagnosis.

Volume-based parameter of 18)F-FDG PET/CT in malignant pleural mesothelioma: prediction of therapeutic response and prognostic implications.

BACKGROUND: To evaluate the importance of assessing volume-based parameter of (18)F-FDG PET/CT in patients with malignant pleural mesothelioma (MPM) for the prediction of response and patient outcome early in the course of treatment. MATERIALS AND METHODS: Patients (n = 13; M:F = 9:4, mean age, 54 years) with histopathologically proven MPM, all of whom were scheduled to undergo curative extrapleural pneumonectomy (EPP) or palliative chemotherapy, were included in this study. They were evaluated using integrated (18)F-FDG PET/CT at baseline. Maximum standardized uptake value (SUVmax), average SUV (SUVavg), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured using PET/CT data. Relationships between tumor progression and PET parameters were statistically analyzed. RESULTS: Of the 13 patients, 8 (62%) developed disease recurrence after surgery or tumor progression after chemotherapy (median follow-up, 329 days; range, 28-536 days). Between subgroups with and without tumor progression, significant differences were noted in MTV (P = 0.045). On ROC curve analysis, MTV (AUC = 0.850, 95% confidence interval [95% CI] 0.550-0.977) and TLG (AUC = 0.800, 95% CI 0.494-0.960) showed good predictive performance for tumor progression. Multivariate analysis adjusted for treatment modality showed that MTV (HR 1.003, P = 0.025) and TLG (HR 1.001, P = 0.031) were independent factors associated with tumor progression. Time to tumor progression was shorter in patients with a high volume-based parameter of PET than in those with a low value. CONCLUSIONS: Volume-based parameters of (18)F-FDG PET/CT have the potential to provide prognostic information in MPM patients who are receiving surgery or palliative chemotherapy.

Assessing operating characteristics of CAD algorithms in the absence of a gold standard.

PURPOSE: The authors examine potential bias when using a reference reader panel as "gold standard" for estimating operating characteristics of CAD algorithms for detecting lesions. As an alternative, the authors propose latent class analysis (LCA), which does not require an external gold standard to evaluate diagnostic accuracy. METHODS: A binomial model for multiple reader detections using different diagnostic protocols was constructed, assuming conditional independence of readings given true lesion status. Operating characteristics of all protocols were estimated by maximum likelihood LCA. Reader panel and LCA based estimates were compared using data simulated from the binomial model for a range of operating characteristics. LCA was applied to 36 thin section thoracic computed tomography data sets from the Lung Image Database Consortium (LIDC): Free search markings of four radiologists were compared to markings from four different CAD assisted radiologists. For real data, bootstrap-based resampling methods, which accommodate dependence in reader detections, are proposed to test of hypotheses of differences between detection protocols. RESULTS: In simulation studies, reader panel based sensitivity estimates had an average relative bias (ARB) of -23% to -27%, significantly higher (p-value < 0.0001) than LCA (ARB--2% to -6%). Specificity was well estimated by both reader panel (ARB -0.6% to -0.5%) and LCA (ARB 1.4%-0.5%). Among 1145 lesion candidates LIDC considered, LCA estimated sensitivity of reference readers (55%) was significantly lower (p-value 0.006) than CAD assisted readers' (68%). Average false positives per patient for reference readers (0.95) was not significantly lower (p-value 0.28) than CAD assisted readers' (1.27). CONCLUSIONS: Whereas a gold standard based on a consensus of readers may substantially bias sensitivity estimates, LCA may be a significantly more accurate and consistent means for evaluating diagnostic accuracy.

Incremental value of PET/CT Over CT for mediastinal nodal staging of non-small cell lung cancer: Comparison between patients with and without idiopathic pulmonary fibrosis.

OBJECTIVE: We aimed to compare the incremental value of FDG PET/CT over CT for the assessment of mediastinal nodal status between patients with non-small cell lung cancer (NSCLC) and idiopathic pulmonary fibrosis (IPF) and those with NSCLC but without IPF. MATERIALS AND METHODS: Forty-two patients with NSCLC and IPF (mean age, 66 years) were matched to 168 patients with NSCLC but without IPF (mean age, 65 years). Patients underwent surgical mediastinal nodal staging after both integrated PET/CT and contrast-enhanced CT scans had been obtained. Histopathologic nodal assessment served as the reference standard. RESULTS: PET/CT had better specificity (91% [29/32 patients] vs 47% [15/32]; p = 0.0002) and accuracy (83% [35/42] vs 50% [21/42]; p = 0.001) than CT did in patients with IPF. In patients without IPF, PET/CT was better than CT alone with regard to sensitivity (62% [26/42] vs 40% [17/42]; p = 0.0067), specificity (96% [121/126] vs 84% [106/126]; p = 0.0002), and accuracy (88% [147/168] vs 73% [123/168]; p < 0.0001). Thus, the incremental accuracy of PET/CT, which was 33% (14/42) for patients with IPF and 14% (24/168) for patients without IPF (p = 0.0041), was mainly the result of improved specificity. CONCLUSION: PET/CT offers significantly increased accuracy versus CT in mediastinal nodal staging in patients with NSCLC and IPF compared with patients with NSCLC but without IPF, mainly because of improved specificity.

Cryptogenic organizing pneumonia: serial high-resolution CT findings in 22 patients.

OBJECTIVE: We conducted a review of serial high-resolution CT (HRCT) findings of cryptogenic organizing pneumonia (COP). MATERIALS AND METHODS: Over the course of 14 years, we saw 32 patients with biopsy-confirmed COP. Serial HRCT scans were available for only 22 patients (seven men and 15 women; mean age, 52 years; median follow-up period, 8 months; range, 5-135 months). Serial CT scans were evaluated by two chest radiologists who reached a conclusion by consensus. Overall changes in disease extent were classified as cured, improved (i.e., ≥ 10% decrease in extent), not changed, or progressed (i.e., ≥ 10% increase in extent). When there were remaining abnormalities, the final follow-up CT images were analyzed to express observers' ideas regarding what type of interstitial lung disease the images most likely suggested. RESULTS: The two most common patterns of lung abnormality on initial scans were ground-glass opacification (86% of patients [19/22]) and consolidation (77% of patients [17/22]), distributed along the bronchovascular bundles or subpleural lungs in 13 patients (59%). In six patients (27%), the disease disappeared completely; in 15 patients (68%), the disease was decreased in extent; and in one patient (5%), no change in extent was detected on follow-up CT. When lesions remained, the final follow-up CT findings were reminiscent of fibrotic nonspecific interstitial pneumonia in 10 of 16 patients (63%). CONCLUSION: Although COP is a disease with a generally good prognosis, most patients (73%) with COP have some remaining disease seen on follow-up CT scans, and, in such cases, the lesions generally resemble a fibrotic nonspecific interstitial pneumonia pattern.

Bronchoscopic features and bronchoscopic intervention for endobronchial hamartoma.

BACKGROUND AND OBJECTIVE: Bronchoscopic resection of endobronchial hamartomas has been reported to have a favourable outcome. This study describes the bronchoscopic features of endobronchial hamartoma and reports the clinical outcome of bronchoscopic intervention. METHODS: A retrospective analysis was conducted of patients with histologically proven endobronchial hamartomas, diagnosed in the 10-year period 1999-2009 to elucidate the clinical, radiological and bronchoscopic features of hamartoma and to describe the clinical outcomes. RESULTS: Seventeen of the 135 patients with pulmonary hamartomas were diagnosed as having endobronchial hamartomas. CXR was abnormal in 11 of the 17 patients. On chest CT (n = 16), the median diameter of the lesion was 15.6 mm. Calcification and areas of focal fat in the lesion, the diagnostic CT findings of pulmonary hamartoma, were found in two of 16 (12.5%) patients. At bronchoscopy (n = 16), all tumours had a mass appearance and most were smooth surfaced round masses (50.0%) with 18.8% having a 'stalk'. Bronchoscopic forceps biopsies were performed in 13 patients, which resulted in five patients (38.5%) being diagnosed with endobronchial hamartoma. Fifteen patients were treated with rigid or flexible bronchoscopic resection, one had lobectomy, and one had no intervention. No procedure-related mortalities or late complications developed. CONCLUSIONS: Bronchoscopic intervention appears to be a safe and effective method to resect endobronchial hamartomas.