Noncalcified Nodules Research Articles

Measurement Methods and Algorithms for the Management of Solid Nodules

The increased detection of incidental small pulmonary nodules on multidetector computed tomography has driven attempts to refine the characterization and management of such nodules. A variety of methods have been developed to measure the size and biological activity of nodules to help define their nature, but these have limitations. Several clinical trials have assessed the efficacy of low-dose computed tomography screening for lung cancer and offer some insights into these limitations; however, they also provide evidence that refines existing nodule management strategies. This article reviews the size-based and functional measurement methods that can be used to predict the likelihood of malignancy in noncalcified solid pulmonary nodules and discusses their incorporation into existing algorithms for nodule management. The issue of multiple nodules and the optimum frequency and duration of follow-up are explored.

Improved Efficiency of CT Interpretation Using an Automated Lung Nodule Matching Program

The purpose of this study was to assess the impact of an automated program on improvement in lung nodule matching efficiency. Four thoracic radiologists independently reviewed two serial chest CT examinations from each of 57 patients. Each radiologist performed timed manual lung nodule matching. After 6 weeks, all radiologists independently repeated the timed matching portion using an automated nodule matching program. The time required for manual and automated matching was compared. The impact of nodule size and number on matching efficiency was determined. An average of 325 (range, 244-413) noncalcified solid pulmonary nodules was identified. Nodule matching was significantly faster with the automated program irrespective of the interpreting radiologist (p < 0.0001 for each). The maximal time saved with automated matching was 11.4 minutes (mean, 2.3 ± 2.0 minutes). Matching was faster in 56 of 57 cases (98.2%) for three readers and in 46 of 57 cases (80.7%) for one reader. There were no differences among readers with respect to the mean time saved per matched nodule (p > 0.5). The automated program achieved 90%, 90%, 79%, and 92% accuracy for the four readers. The improvement in efficiency for a given patient using the automated technique was proportional to the number of matched nodules (p < 0.0001) and inversely proportional to nodule size (p < 0.05). Use of the automated lung nodule matching program significantly improves diagnostic efficiency. The time saved is proportionate to the number of nodules identified and inversely proportional to nodule size. Adoption of such a program should expedite CT examination interpretation and improve report turnaround time.

Effect of greyscale liquid crystal displays of different resolutions on observer performance during detection of small solitary pulmonary nodules

The aim of this study was to evaluate the effect of monochrome liquid crystal displays (LCDs) with different resolutions on observer performance during detection of small solitary pulmonary nodules. Chest images of digital radiography were selected online from the hospital's picture archiving and communication system. Of the 164 images selected, small solitary non-calcified pulmonary nodules were present in 63 images and absent in 101 images. Observer performance was assessed among 3 extremely experienced, 3 very experienced and 3 moderately experienced radiologists, who independently interpreted these images on 2, 3 and 5 megapixel greyscale LCDs. A five-point confidence level rating scale was used to represent the presence of nodules: definite absence, probable absence, indetermination, probable presence and definite presence. The observers were requested to rank each image on the given display according to the presence of the pulmonary nodule. Observer performance was analysed in terms of receiver operating characteristics (ROCs). The areas under the ROC curves which represented the observer performance for the 2, 3 and 5 megapixel LCDs were found to be 0.705, 0.722 and 0.764, respectively, for the extremely experienced radiologists; 0.687, 0.712 and 0.721, respectively, for the very experienced radiologists; and 0.689, 0.696 and 0.711, respectively, for the moderately experienced radiologists. These differences were not statistically significant. The observer performances for detection of small solitary non-calcified pulmonary nodules by radiologists with varying degrees of experience were comparable between the 2, 3 and 5 megapixel monochrome LCDs.

Long-term follow-up of non-calcified pulmonary nodules (&lt;10 mm) identified during low-dose CT screening for lung cancer

To assess the long-term stability of small (<10 mm) non-calcified pulmonary nodules (NCNs) in high-risk subjects initially screened for lung cancer using low-dose chest computed tomography (LDCCT). A total of 449 subjects initially underwent screening with serial LDCCT over a 2-year period. Participants identified as having NCNs ≥10 mm were referred for formal lung cancer workup. NCNs <10 mm diameter were followed in accordance with the study protocol. Seven years after baseline screening, subjects with previously documented NCNs <10 mm, which were unchanged in size after the 2-year follow-up period, were re-imaged using LDCCT to assess for interval nodule growth. Eighty-three subjects with previously documented stable NCNs <10 mm underwent LDCCT at 7 years. NCNs were unchanged in 78 subjects and had decreased in size in 4 subjects. There was interval growth of an NCN (from 6 mm to 9 mm) in one subject re-imaged at 7 years, but this nodule has remained stable in size over a further 2-year follow-up period. Non-calcified pulmonary nodules <10 mm in size that are unchanged in size or smaller after 2 years of follow-up with LDCCT are most likely benign.

Aortoiliac CT Angiography for Planning Transcutaneous Aortic Valve Implantation: Aortic Root Anatomy and Frequency of Clinically Significant Incidental Findings

The purpose of this article is to assess aortic root and iliofemoral vessel anatomy and the frequency of clinically significant incidental findings on aortoiliac CT angiography (CTA) performed for planning of transcutaneous aortic valve implantation. Aortoiliac CTA studies of 207 patients scheduled for transcutaneous aortic valve implantation were analyzed. Anatomic dimensions relevant to the interventional procedure, including diameter of the aortic annulus and sinus of Valsalva, distance between aortic annulus and coronary ostia, coronary leaflet length, left ventricular outflow tract diameter, and vessel diameter of iliac arteries, were analyzed. Clinically significant incidental findings were recorded. The mean (± SD) maximum and minimum diameters of the aortic annulus were 29 ± 3.9 mm and 23.5 ± 4.1 mm, respectively. The mean distances between aortic annulus and the ostium of the left and right coronary artery were 13.5 ± 3.2 mm and 14.8 ± 3.9 mm, respectively. The mean maximum and minimum diameters of the left ventricular outflow tract were 27 ± 4 mm and 1.9 ± 4 mm, respectively. The mean diameter of the sinus of Valsalva was 33.4 ± 5.1 mm. The mean diameters of the right and left external iliac artery were 8 ± 1 and 8 ± 2 mm, respectively. Almost half the patients (101/207) had clinically significant incidental findings, including noncalcified pulmonary nodules larger than 8 mm (n = 7), pulmonary embolism (n = 3), or aortic aneurysm (n = 12). Aortoiliac CTA provides relevant information on aortic root and iliofemoral vessel anatomy for preinterventional planning. CTA reveals clinically significant incidental findings in a high number of patients considered for transcutaneous aortic valve implantation, which may have a significant impact on patient selection.

Lung Morphology Assessment with Balanced Steady-State Free Precession MR Imaging Compared with CT

To evaluate the utility of 1.5-T noncontrast magnetic resonance (MR) imaging of the lung parenchyma and to compare it with computed tomography (CT) in the assessment of interstitial lung disease and other morphologic lung abnormalities. Institutional review board approval was obtained for retrospective image analysis. A total of 236 patients who underwent MR imaging and CT as part of their assessment for suspected pulmonary hypertension were included in this study. Lung MR imaging was performed with a 1.5-T system as a stack of axial two-dimensional balanced steady-state free precession (bSSFP) acquisitions. Two radiologists independently evaluated CT and MR images for various morphologic abnormalities, such as pulmonary fibrosis, pleural and mediastinal disease, solid lesions, bronchial disease, and emphysema. Κ statistics were used to measure interobserver agreement. Sensitivity and specificity of MR imaging in the identification of pulmonary fibrosis (n = 46) were 89% (95% confidence interval: 77%, 96%) and 91% (95% confidence interval: 76%, 98%), respectively, when compared with CT. In comparison to CT, MR imaging depicted 75% of ground-glass opacities. Nine of the 12 noncalcified nodules were identified on MR images. Lung nodules (75%, κ = 0.71) and effusions (100%, κ = 0.89) were also well visualized on MR images. MR imaging was however less effective in depicting emphysema (16%, κ = 0.60) and minor fibrosis (67%, κ = 0.79). This study shows bSSFP MR imaging is inferior to CT in imaging parenchymal lung disease; however, this study does demonstrate for the first time a potential role for the bSSFP sequence as an alternative radiation-free noncontrast imaging modality for use in patients with pulmonary fibrosis.

Computed Axial Tomography Scans, Calories, and Computers

Low-dose computed tomography (LDCT) has shown promise in the early detection of lung cancer in prior observational studies. The National Lung Screening Trial (NLST) is the largest multicenter, randomized, controlled trial comparing LDCT with chest radiography with an intention-to-screen analysis (1). High-risk (.30 pack-years) active or ex-smokers between 55 and 74 years of age (n 1⁄4 53,454) were screened three times at 1-year intervals and followed for a median of 6.5 years. Lesions suspicious for cancer (noncalcified nodules . 4 mm) were found in 39.1% of individuals with LDCT and 16.0% with radiography during the trial. A total of 96.4% of these lesions in the LDCT group and 94.5% in the radiography group were false-positive results. The LDCT group had 247 deaths from lung cancer per 100,000 person-years and the radiography group had 309 deaths per 100,000 person-years. This meant a 20% (95% CI, 6.8–26.7; P 1⁄4 0.004) relative reduction in mortality from lung cancer, and a 6.7% (95% CI, 1.2–13.6; P 1⁄4 0.02) reduction in all-cause mortality with LDCT screening. Of the 17,053 LDCT lesions suspicious for cancer in which cancer was not confirmed, 457 (2.7%) resulted in an invasive procedure, with 11 (0.06%) major complications. Multiple unanswered questions regarding lung cancer screening remain. First, this study was done at large centers of excellence, with potentially different results at smaller hospitals. Second, 1,060 individuals in the LDCT and 941 in the radiography group were found to have lung cancer, suggesting the possibility of overdiagnosis with LDCT (2). Are there individuals who die with, rather than from, lung cancer (3)? Third, the implications for smoking cessation are unclear. Smokers might use screening as a tool to continue smoking. Alternatively, a positive screening test might also induce smokers to quit. Last, there are unanswered questions about the optimal demographic group to screen (age, sex, and smoking history), frequency and duration of screening, risks of increasing radiation exposure, risks of false-positive tests, and cost. The number of LDCT screening tests needed to prevent one lung cancer death was 320. I believe this study should not inform health policy decision making until these questions are better answered.

Detection of noncalcified pulmonary nodules on low-dose MDCT: comparison of the sensitivity of two CAD systems by using a double reference standard

This study compared the sensitivity of two commercial computer-aided detection (CAD) systems in identifying noncalcified pulmonary nodules on low-dose multidetector computed tomography (MDCT) scans by using a double reference standard. Three chest low-dose MDCT scans of patients who had undergone lung cancer screening were retrospectively analysed using two distinct commercial CAD systems: LungCAD VC10A, Siemens Medical Solutions (CAD1) and LungVCAR, GE Healthcare (CAD2). The exact location of each finding suggested by each system was recorded by an independent reader according to spatial coordinates (x, y, z). Two panels of experienced thoracic radiologists from two different institutions independently established two reference standards (RS1, RS2) by identifying the true positive findings with spatial coordinates without using CAD. Sensitivity of the two CAD systems, defined by lesionlevel analysis, was tested and sensitivities compared. RS1 identified 34 noncalcified pulmonary nodules, whereas RS2 identified 54. The total number of findings detected by the two CAD systems was 684. CAD1 correctly identified 13/34 nodules (sensitivity 38%) for RS1 and 17/54 (sensitivity 30%) for RS2, whereas CAD2 correctly identified 11/34 nodules (sensitivity 35%) for RS1 and 13/54 (sensitivity 23%) for RS2. Comparison between the two CAD systems did not show a statistically significant difference in terms of sensitivity (p<0.05) for both RS1 (p=0.42) and RS2 (p=0.33). The two commercial CAD systems had similar sensitivity in detecting noncalcified pulmonary nodules on low-dose MDCT of the chest.

Screening for lung cancer: Is this the way forward?

While low-dose CT scans have been shown to detect greater numbers of early lung cancers than conventional CXR, the first randomized trial of CT versus CXR screening in more than 50 000 subjects has shown a 20% reduction in mortality with CT. There are several other randomized trials in progress. CT scanning may be a useful technique for identifying lung cancer at an earlier stage and may reduce mortality. However, before it can be used on a wider scale, issues such as overdiagnosis bias, cost-effectiveness, false positive findings of multiple noncalcified nodules and the willingness of the relevant population to accept CT scanning need to be evaluated. There is still very little information on the cost per life-year saved as a result of CT scanning, as the data to date is very imprecise. There is no evidence that screening programs influence smoking rates despite the inclusion of cessation programs in many trials. Furthermore, if CT screening is adopted, much work is needed to persuade individuals at high risk, mostly current or former heavy smokers with some airflow obstruction, to participate in a screening program.

Prevalence of Thyroid Cancer in Thyroid Nodules with Dense Calcification

목적: 갑상선 결절은 흔하게 발견되며 약 5%에서 갑상선 암으로 진단되므로 악성 결절과 양성 결절을 구분하는 것이 중요하다. 최근 고해상도 갑상선 초음파의 발달로 악성을 시사하는 초음파 소견을 예측하고자 다양한 연구가 진행되었고, 미세석회화와 악성화의 연관성이 확립된 반면, 거대석회화와 갑상선암의 연관성에 대한 논란이 있어 다수를 대상으로 후향적 연구를 시행하였다. 방법: 5년 동안 갑상선 결절로 인하여 화순전남대병원을 방문하여 갑상선 초음파를 시행하였던 환자들 중에서 갑상선적출술을 받았거나, 갑상선암의 위험인자로 잘 알려진 미세석회화를 동반하는 경우를 제외하고, 거대석회화 유무에 따라 두 군으로 구분하여 갑상선 초음파, 미세침흡인세포 검사 결과 및 수술을 통한 병리 결과를 확인하였다. 결과: 거대석회화를 동반하는 군에서 악성의 빈도는 22.7% (37/163)로 석회화가 불분명하거나 없는 군의 악성 결절의 빈도가 13.4% (271/2,021)인 것과 비교하여 통계학적으로 유의하게 높았고(p < 0.01), 비정형 및 악성의심 결절의 빈도도 유의하게 높았다(p < 0.01). 거친석회화 군에서 변연부석회 화군에 비해 통계학적 의의는 없었지만 악성의 빈도가 높았다(30.1% vs. 16.2%). 결론: 거대석회화를 동반한 갑상선 결절은 악성의 빈도가 높으며, 부적절한 검체를 얻을 확률이 높으므로 주의 깊은 미세침흡인세포검사 및 추적검사가 필요하다.

Paraneoplastic Pemphigus (PNP) As a Presenting Finding in a Patient with Hodgkin's Lymphoma

Abstract 4864 Introduction:We report a case of PNP in a patient who was subsequently diagnosed with classical Hodgkins Lymphoma mixed cellularity type. PNP is an autoimmune mediated blistering disorder that presents with skin lesions demonstrating characteristics of erythema multiforme and pemphigus vulgaris. Case:A 76 year-old Hispanic male presented to the Emergency department with intermittent low fevers of 4 months duration associated with progressive weakness and fatigue; he now had mouth ulcers of 1-week duration along with anorexia. Physical exam was significant for a temperature of 102.4F, bilateral conjunctivitis with mild white discharge. Labs included WBC 5,000/mm3, hemoglobin 9.5 gm/dL, platelets 99,000/mm3; differential showed lymphocytes 22%, monocytes 11%, eosinophils 3%, and myelocytes 9%. Oral examination revealed dry mucosa with bleeding perioral ulcers. An ulcer biopsy was obtained and demonstrated necrotic keratinocytes and necrotic neutrophilic inflammation consistent with PNP. Chest CT showed a multinodular goiter, enlarged mediastinal and hilar nodes with calcified granulomas bilaterally as well as a new noncalcified nodule in the right lung. PET scan revealed FDG avid lymph nodes in the left supraclavicular, hilar and left axilla areas as well as multiple regions in the spleen and retroperitoneal nodes. A left axillary node biopsy showed classical Hodgkins lymphoma of mixed cellularity type. The patient was started on prednisone 75 mg per day in divided doses and his oral ulcerations and clinical status improved after 2 days of therapy. Subsequently the patient was started on gemcitabine, vinorelbine and liposomal doxorubicin (GVD) chemotherapy for his malignancy. Discussion:Although PNP has been described as being associated with hematologic malignancies such as Non-Hodgkins Lymphoma, Chronic Lymphocytic Leukemia and Castleman's disease, it has rarely been demonstrated in association with classical Hodgkins disease. This case report highlights the need for a higher index of suspicion of underlying malignancy including classical Hodgkins disease when confronted with a patient presenting PNP. Disclosures:No relevant conflicts of interest to declare.

Common Incidental Findings on MDCT: Survey of Radiologist Recommendations for Patient Management

The aim of this study was to evaluate for agreement with respect to how radiologists report incidental findings encountered on CT. A multiple-choice survey was designed to query radiologists about how they handle 12 incidental findings on body CT, assuming the patient is a 45-year-old woman with no history of malignancy. Included were a 1-cm thyroid nodule, a 5-mm noncalcified lung nodule, coronary artery calcification, a 2-cm adrenal nodule, a 2-cm pancreatic cyst, a 1-cm enhancing liver lesion, a 2-cm high-density renal cyst, short-segment small bowel intussusception, a 1-cm splenic cyst, focal gallbladder wall calcification, and a 3-cm ovarian cyst in both a premenopausal woman and a postmenopausal woman. Choices ranged from "do not report" to advising interventional procedures tailored to the organ. Surveys were administered to body CT attending radiologists at 3 academic institutions. Twenty-seven radiologists completed the survey. The mean experience level was 15.7 years after training. Seventy percent or greater agreement on interpretation was identified for only 6 findings: recommend ultrasound for a 1-cm thyroid nodule, recommend ultrasound for a 3-cm cyst in postmenopausal woman, follow Fleischner Society recommendations for a 5-mm lung nodule, describe only coronary calcification, and describe as likely benign both short-segment small bowel intussusception and a 1-cm splenic cyst. Agreement is lacking, both across institutions and within departments, for the management of 6 commonly encountered incidental findings on body CT. Individual departments should develop internal guidelines to ensure consistent recommendations based on existing evidence.

Pulmonary nodules: Effect of adaptive statistical iterative reconstruction (ASIR) technique on performance of a computer-aided detection (CAD) system—Comparison of performance between different-dose CT scans

PurposeTo evaluate the effects of ASIR on CAD system of pulmonary nodules using clinical routine-dose CT and lower-dose CT. Materials and methodsThirty-five patients (body mass index, 22.17±4.37kg/m2) were scanned by multidetector-row CT with tube currents (clinical routine-dose CT, automatically adjusted mA; lower-dose CT, 10mA) and X-ray voltage (120kVp). Each 0.625-mm-thick image was reconstructed at 0%-, 50%-, and 100%-ASIR: 0%-ASIR is reconstructed using only the filtered back-projection algorithm (FBP), while 100%-ASIR is reconstructed using the maximum ASIR and 50%-ASIR implies a blending of 50% FBP and ASIR. CAD output was compared retrospectively with the results of the reference standard which was established using a consensus panel of three radiologists. Data were analyzed using Bonferroni/Dunn's method. Radiation dose was calculated by multiplying dose-length product by conversion coefficient of 0.021. ResultsThe consensus panel found 265 non-calcified nodules ≤30mm (ground-glass opacity [GGO], 103; part-solid, 34; and solid, 128). CAD sensitivity was significantly higher at 100%-ASIR [clinical routine-dose CT, 71% (overall), 49% (GGO); lower-dose CT, 52% (overall), 67% (solid)] than at 0%-ASIR [clinical routine-dose CT, 54% (overall), 25% (GGO); lower-dose CT, 36% (overall), 50% (solid)] (p<0.001). Mean number of false-positive findings per examination was significantly higher at 100%-ASIR (clinical routine-dose CT, 8.5; lower-dose CT, 6.2) than at 0%-ASIR (clinical routine-dose CT, 4.6; lower-dose CT, 3.5; p<0.001). Effective doses were 10.77±3.41mSv in clinical routine-dose CT and 2.67±0.17mSv in lower-dose CT. ConclusionCAD sensitivity at 100%-ASIR on lower-dose CT is almost equal to that at 0%-ASIR on clinical routine-dose CT. ASIR can increase CAD sensitivity despite increased false-positive findings.

Solitary pulmonary nodule: A diagnostic algorithm in the light of current imaging technique

The solitary pulmonary nodule (SPN) is frequently seen on chest radiographs and computed tomography (CT). The finding of a SPN usually provokes a flurry of clinical and imaging activity as an SPN in at-risk population is an alert signal of possible lung cancer. The frequency of malignant nodules in a given population is variable and depends on the endemicity of granulomatous disease. The percentage of malignant nodules also rises when dealing with at-risk population. The problem is compounded by the fact that with the present generation of CT scanners, 1–2 mm nodules are discovered in approximately half of the smokers aged 50 years or older scanned. A variety of management approaches are applied in the work-up of SPN often requiring evaluation over a long period of time to establish a benign or malignant diagnosis. Comparison with previous imaging studies and morphologic evaluation of the size, margins, and internal characteristics are usually the first step in the evaluation of these nodules. It is often necessary to use additional imaging techniques and occasionally invasive procedures such a percutaneous needle lung or a surgical biopsy. Until recently, the guidelines for follow-up of indeterminate noncalcified nodules detected on nonscreening CT was a minimum of 2 years. However, during the past few years due to further refinements in CT technology and better understanding of tumor behavior, it has prompted a revision of the guidelines of the follow-up of small indeterminate nodules. These guidelines have been endorsed by the Fleischner Society.

Calcifications in thyroid nodules identified on preoperative computed tomography: Patterns and clinical significance

The purpose of this study was to evaluate the patterns and clinical importance of calcifications in thyroid nodules identified on preoperative computed tomography (CT). CT of 383 patients undergoing thyroid operations were reevaluated to identify thyroid calcification. A novel classification for thyroid calcifications on CT images was applied. The prevalence and patterns of calcification were classified, analyzed, and correlated with clinical and histopathologic findings. Of the 383 patients, 135 (35.2%) had intrathyroidal calcifications identified on CT. Among these 135 patients, 65 (48%) were found to have thyroid cancer on definitive histopathology. Theincidence of cancer was greater in calcified nodules (48%) than in noncalcified nodules (20%; P< .001). According to the calcification patterns, 2 of 9 (22%) nodules with peripheral calcification, 11 of 52 (21%) nodules with coarse calcification, 18 of 31 (58%) nodules with a single punctate calcification, and 34 of 43 (79%) nodules with multiple punctate calcifications were malignant. In the subset of 42 patients who presented with a solitary calcified nodule, 35 (83%) were found to have cancer. In addition, the incidence of lymph node metastases is greater in malignant nodules with calcification than in those without (48% vs 25%; P = .01). Thyroid calcification found on preoperative CT may represent an increased risk for thyroid malignancy. When the pattern shows multiple punctate calcification or the calcification is noted within a solitary nodule, the risk of malignancy is high in this study.

Longitudinal predictors of adherence to annual follow-up in a lung cancer screening programme

To examine rates and factors associated with adherence to annual repeat lung cancer screening in two cohorts. Participants and methods The self-pay cohort (n = 2083) was individuals aged 40 years and older with no prior cancer and a smoking history. Participants had to obtain a prescription from their doctor for the low dose, computerized tomography scan (CT), and were responsible for payment of $300 as these CT scans are not typically covered by insurance. The no-pay cohort (n = 1304) was individuals aged 60 and older with a smoking history, and no prior cancer. The initial and one year repeat CT were provided free of charge. Rates of adherence for each cohort were analyzed by demographic variables, smoking history, family history of lung cancer, smoking status (former/current), perceived risk and worry of getting lung cancer and baseline screening CT. Adherence to annual follow-up was lower for the self-pay than for the no-pay cohort (62% vs. 88%). Both the self-pay and no-pay cohorts had higher adherence rates among Caucasians and those who had a college degree. A greater perceived risk of getting lung cancer increased adherence among the self-pay cohort. Non-calcified nodules found on baseline CT increased the adherence for the self-pay cohort, but decreased the adherence for the no-pay cohort. These findings should be used in developing educational materials and targeted retention strategies to increase adherence with repeat lung cancer screening.

Abstract 3679: Preliminary results from a patient group, excluded from the National Lung Cancer Screening Trial, who are at high risk for lung cancer- heavy smokers with HIV

Abstract Purpose: Within the HIV population, the incidence of lung cancer is estimated to be 2-4 times that of the general population. Of the non AIDS associated malignancies, lung cancer is the leading cause of death among HIV patients who develop malignancy because of its advanced stage of presentation. The National Lung Cancer Screening Trial recently reported a 20% reduction in mortality for patients undergoing low dose computed tomography (CT) screening, but individuals with HIV diagnosis were excluded. To report the results of an observational pilot study of lung cancer CT screening in a cohort of HIV heavy smokers. Materials and Methods: A prospective cohort study was performed with 185 asymptomatic individuals with confirmed HIV diagnosis who had smoked 20 pack-years or more. All participants had baseline (prevalence) chest CT scanning and 107 patients (58.2%) also received at least one subsequent annual (incidence) examination of the chest and upper abdomen. All patients underwent hand held spirometry testing, cytologic analysis of sputa, and detailed health status questioning. Results: Of the 185 individuals, there were 31.4% females, 68.6% males, 90.3% African-Americans, 8.7% Caucasian, and 1.1% Hispanic. The median age at enrolment was 48 years, and the median number of smoking pack-years was 34. Non-calcified nodules were detected in 4 participants (2.1%) by low-dose prevalent CT compared to no nodules on incident CT scans. Only one patient with malignancy was detected (0.54%) on prevalent scanning and none on incident scanning. Stage of malignancy was advanced. No biopsies were undertaken for benign disease. CT evidence of COPD and coronary artery disease were present in 24% and 27% of patients, respectively. Additional CT findings of clinical importance were noted in the chest in 132 (71.7%) patients and extrathoracically in 30 (16.3%) of patients, respectively. Conclusion: The prevalence results of this pilot study are in line with other observational studies of greater sample size for HIV indeterminate patients. Although the sample size is small, it suggests no elevated incidence of lung cancer in HIV heavy smokers. Although the rate of incident scanning is low, CT screening of HIV patients is feasible. This justifies accruing a larger sample of HIV patients perhaps from an already well defined, large, prospective cohort of HIV heavy smokers. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3679. doi:10.1158/1538-7445.AM2011-3679

Potential contribution of multiplanar reconstruction (MPR) to computer-aided detection of lung nodules on MDCT

To evaluate potential benefits of using multiplanar reconstruction (MPR) in computer-aided detection (CAD) of lung nodules on multidetector computed tomography (MDCT). MDCT datasets of 60 patients with suspected lung nodules were retrospectively collected. Using "second-read" CAD, two radiologists (Readers 1 and 2) independently interpreted these datasets for the detection of non-calcified nodules (≥ 4 mm) with concomitant confidence rating. They did this task twice, first without MPR (using only axial images), and then 4 weeks later with MPR (using also coronal and sagittal MPR images), where the total reading time per dataset, including the time taken to assess the detection results of CAD software (CAD assessment time), was recorded. The total reading time and CAD assessment time without MPR and those with MPR were statistically compared for each reader. The radiologists' performance for detecting nodules without MPR and the performance with MPR were compared using jackknife free-response receiver operating characteristic (JAFROC) analysis. Compared to the CAD assessment time without MPR (mean, 69s and 57s for Readers 1 and 2), the CAD assessment time with MPR (mean, 46s and 45s for Readers 1 and 2) was significantly reduced (P<0.001). For Reader 1, the total reading time was also significantly shorter in the case with MPR. There was no significant difference between the detection performances without MPR and with MPR. The use of MPR has the potential to improve the workflow in CAD of lung nodules on MDCT.

18-Fluorine Fluorodeoxyglucose Positron Emission Tomography with Computerized Tomography Versus Computerized Tomography Alone for the Management of Solitary Lung Nodules with Diameters Inferior to 1.5 cm

Aim of the study was to establish a noninvasive method for the preoperative characterisation of a pulmonary nodule when biopsy of the small mass is impossible. From 1 January 2006 to 31 December 2008, we observed 124 asymptomatic patients with a noncalcified single lung nodule highlighted by computerised tomography (CT) of the thorax. Patients were divided into 2 groups: Group A consisted of 57 patients with lesion diameters between 0.5 cm and 0.99 cm; Group B consisted of 67 patients with lesion diameters between 1.0 cm and 1.5 cm. Fibreoptic bronchoscopy was negative for endobronchial neoformation in all patients. The topographic distribution of the lesions advised against CT-guided transthoracic needle biopsy or video-assisted thoracoscopy. All patients had preoperative 18-fluorine fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) associated with CT of the thorax, which was compared with CT for evaluation of the mass. Postoperative histological diagnosis revealed 54 primary lung cancers, 47 lung metastases and 23 benign lesions. In Group A the sensitivity of 18F-FDG PET/CT and CT was 95 % and 73 % and the specificity was 72 % and 64 %, respectively ( P = 0.000001 for 18F-FDG PET/CT; P = 0.000177 for CT). In Group B the sensitivity of 18F-FDG PET/CT and CT was 95 % and 97 %, and the specificity was 80 % and 87 %, respectively ( P = 0.000001). Our study shows that 18F-FDG PET/CT improves the identification and characterisation of potentially malignant pulmonary nodules with a diameter < 1 cm. This technique could be a valid alternative to a surgical approach, currently the main method to investigate indeterminate lung nodules.

Frequency and significance of pulmonary nodules on thin-section CT in patients with extrapulmonary malignant neoplasms

To determine the frequency and significance of pulmonary nodules detected on thin-section CT in patients with extrapulmonary malignant neoplasms. The institutional review board approved this study. This study retrospectively evaluated 308 patients with extrapulmonary carcinomas or sarcomas and had undergone thin-section chest CT (2mm slice thickness) for staging. Three radiologists identified non-calcified nodules and evaluated the size, the growth and the distance from the nearest pleural surface. The characteristics of the nodules were defined based on the results of either a diagnostic biopsy or nodule growth. One or more non-calcified pulmonary nodules were detected in 75% of the patients (233/308). One hundred and thirty-seven of these patients had nodules that met the criteria of either benign or malignant nodules. Nodules smaller than 10mm were more likely to be benign, whereas those 10mm or greater were more likely to be malignant (22/26, 85%; P<.0001). Most nodules less than 10mm from the pleura were benign (91%), whereas approximately half of the nodules 10mm or more away from the pleura were malignant (20/43, 47%; P<.0001). Patients with melanoma, sarcoma, or testicular carcinoma were more likely to have malignant nodules. A multivariable analysis demonstrated the nodule size (P<.0001) and distance from the pleura were predictive of malignancy. The nodule detection rate on thin-section CT in patients with extrapulmonary malignancy is high. Most of the nodules smaller than 10mm or less than 10mm from the pleura are benign.