Managing the Small Pulmonary Nodule Discovered by CT

C-arm cone-beam CT-guided percutaneous transthoracic needle biopsy of small (≤ 20 mm) lung nodules: diagnostic accuracy and complications in 161 patients

OBJECTIVE

The purpose of this study is to retrospectively evaluate the diagnostic accuracy and complications of C-arm cone-beam CT (CBCT)-guided percutaneous transthoracic needle biopsy (PTNB) for small (≤ 20 mm) lung nodules and their possible influencing factors.

MATERIALS AND METHODS

From March 2009 to July 2010, 161 consecutive patients (77 men and 84 women; mean [± SD] age, 61 ± 11.8 years; range, 29-85 years) with 173 small (≤ 20 mm) lung nodules underwent CBCT-guided PTNB performed by an experienced chest radiologist in a tertiary referral hospital. The diagnostic accuracy, sensitivity, specificity, and complication rates were statistically evaluated, and influencing factors were assessed using univariate and subsequent multivariate analysis.

RESULTS

Of 173 nodules (mean size, 15 ± 3.7 mm), 94 (54.3%) were diagnosed as malignant, 69 (39.9%) as benign, and 10 (5.8%) as indeterminate. On PTNB, 160 nodules were correctly diagnosed and three were false-negatives. Diagnostic accuracy, sensitivity, and specificity were 98.2%, 96.8%, and 100%, respectively. No factors significantly decreased diagnostic accuracy. As for complications, pneumothorax, hemoptysis, and chest pain occurred in 55 (31.8%), 25 (14.5%), and two (1.2%) patients, respectively. Multivariate analysis revealed that the presence of emphysema along the needle pathway was a significant risk factor (odds ratio [OR], 10.11), and the occurrence of hemoptysis was a significant protective factor (OR, 0.28) against pneumothorax. Ground-glass nodules were found to be a significant independent risk factor for hemoptysis (OR, 5.10).

CONCLUSION

C-arm CBCT-guided PTNB is highly accurate for small lung nodules, and the diagnostic accuracy does not significantly decrease even in technically challenging conditions.

Radiographic and clinical characterization of false negative results from CT-guided needle biopsies of lung nodules

INTRODUCTION

Computed tomography-guided transthoracic fine-needle aspiration (FNA) is a highly sensitive technique for diagnosing malignancy in pulmonary nodules; however, there is great uncertainty regarding the reliability of a benign result. The goal of this study was to characterize the clinical, radiologic, and technical variables associated with a false negative result.

METHODS

We performed a consecutive series review of patients who had an initial benign result from an FNA between January 2002 and December 2004. Medical charts were reviewed to identify patients with false negative and true negative results and determine which variables were associated with a missed diagnosis.

RESULTS

One hundred and seventy patients underwent an FNA biopsy yielding an initial benign result and had adequate clinical follow-up. Eighteen of these proved to be false negatives and 152 were true negative. Compared with the patients with true negatives, those with false negative results had significantly larger nodules (mean, 27 mm versus 17 mm, p = 0.04), fewer imaging adjustments per needle pass (4.5 versus 6.4, p = 0.01), a higher proportion in whom the needle tip was not documented within the lesion (24% versus 5%, p =0.04), and a higher pneumothorax rate at any point during the procedure (50% versus 22%, p =0.04). When these variables were considered jointly, pneumothorax (p = 0.006), solitary nodule (p = 0.04), and the radiologist who performed the procedure (p = 0.04) were significant predictors of false negative results.

CONCLUSIONS

Factors that were associated with false negative results include increased size of lesion, fewer adjustments of the needle, lack of positive cultures, and the occurrence of a pneumothorax. A benign FNA biopsy result should have the procedure reviewed to ensure the results are reliable.

Proportion and characteristics of transient nodules in a retrospective analysis of pulmonary nodules

BACKGROUND

  Pulmonary nodules manifest as pure or mixed ground glass opacities (GGOs), or solid nodules.

METHODS

  We retrospectively surveyed 317 cases with pulmonary nodules to observe the proportion and predictive factors of transient lesions in patients with pulmonary nodules.

RESULTS

  At the initial computed tomography scan, 63.7% showed solid nodules, while 20.2% had mixed GGOs and 16.1% of cases manifested as pure GGOs. Nodules from 114 cases (36%) disappeared or decreased in size during follow up, while in 203 cases (64%), they did not change or became enlarged. During follow up, more than half of the GGOs resolved (66.7% in pure GGOs, 54.7% in mixed GGOs), while only 22.3% of solid nodules resolved. Between transient and persistent pulmonary nodules, significant differences were observed in age, gender, smoking history, presence of eosinophilia, size, and radiologic attenuation of nodules (solid or GGO). In multivariate analysis, age (≤55 years), size of nodules (>15 mm), eosinophilia, and GGO were significant independent predictors of transient nodules. The main causes of transient nodules were pneumonia or eosinophilic pulmonary infiltrates.

CONCLUSION

  Thirty-six percent of pulmonary nodules resolved spontaneously or with medical treatment. Transient nodules showed different clinical and radiological characteristics from persistent nodules.

Dose exposure in the ITALUNG trial of lung cancer screening with low-dose CT

Few data are available on the effective dose received by participants in lung cancer screening programmes with low-dose CT (LDCT). We report the collective effective dose delivered to 1406 current or former smokers enrolled in the ITALUNG trial who completed 4 annual LDCT examinations and related further investigations including follow-up LDCT, 2-[(18)F]flu-2-deoxy-d-glucose positron emission tomography (FDG-PET) or CT-guided fine needle aspiration biopsy (FNAB). Using the air CT dose index and Monte Carlo simulations on an anthropomorphic phantom, the whole-body effective dose associated with LDCT was determined for the eight CT scanners used in the trial. A value of 7 mSv was assigned to FDG-PET while the measured mean effective dose of CT-guided FNAB was 1.5 mSv. The mean collective effective dose in the 1406 subjects ranged between 8.75 and 9.36 Sv and the mean effective dose to the single subject over 4 years was between 6.2 and 6.8 mSv (range 1.7-21.5 mSv) according to the cranial-caudal length of the LDCT volume. 77.4% of the dose was owing to annual LDCT and 22.6% to further investigations. Considering the nominal risk coefficients for stochastic effects after exposure to low-dose radiation according to the National Radiological Protection Board, International Commission on Radiological Protection (ICRP) 60, ICRP103 and Biological Effects of Ionizing Radiation VII, the mean number of radiation-induced cancers ranged between 0.12 and 0.33 per 1000 subjects. The individual effective dose to participants in a 4-year lung cancer screening programme with annual LDCT is very low and about one-third of the effective dose that is associated with natural background radiation and diagnostic radiology in the same time period.

Advanced imaging: use and misuse

SUMMARY

The primary purpose of diagnostic imaging is to enable clinicians to make correct decisions about a patient's diagnosis and severity of its condition and, thereby, to contribute to effective and efficient treatment. Advanced imaging modalities are inherently better detectors of morphological lesions than radiography; hence, they offer the possibility of more accurate diagnosis and staging, with correspondingly better patient outcomes. However, there is a lack of evidence that better outcomes are being realised for veterinary patients. Furthermore, increased use of advanced imaging carries the possibility of increased misuse, primarily through unnecessary studies that contribute little to patient management other than increased costs.

SCOPE

This article is intended to be relevant to all veterinary species. Advanced imaging of cats is not sufficiently developed as a specific discipline that a balanced review could be based purely on feline examples or references.

¹⁸F-fluoro-deoxy-glucose focal uptake in very small pulmonary nodules: fact or artifact? Case reports

Background

¹⁸F-fluoro-deoxy-glucose (¹⁸ F-FDG) positron emission tomography integrated/combined with computed tomography (PET-CT) provides the best diagnostic results in the metabolic characterization of undetermined solid pulmonary nodules. The diagnostic performance of ¹⁸ F-FDG is similar for nodules measuring at least 1 cm and for larger masses, but few data exist for nodules smaller than 1 cm.

Case presentation

We report five cases of oncologic patients showing focal lung ¹⁸ F-FDG uptake on PET-CT in nodules smaller than 1 cm. We also discuss the most common causes of ¹⁸ F-FDG false-positive and false-negative results in the pulmonary parenchyma.

In patient 1, contrast-enhanced CT performed 10 days before PET-CT did not show any abnormality in the site of uptake; in patient 2, high-resolution CT performed 1 month after PET showed a bronchiole filled with dense material interpreted as a mucoid impaction; in patient 3, contrast-enhanced CT performed 15 days before PET-CT did not identify any nodules; in patients 4 and 5, contrast-enhanced CT revealed a nodule smaller than 1 cm which could not be characterized. The ¹⁸ F-FDG uptake at follow-up confirmed the malignant nature of pulmonary nodules smaller than 1 cm which were undetectable, misinterpreted, not recognized or undetermined at contrast-enhanced CT.

Conclusion

In all five oncologic patients, ¹⁸ F-FDG was able to metabolically characterize as malignant those nodules smaller than 1 cm, underlining that: ¹⁸ F-FDG uptake is not only a function of tumor size but it is strongly related to the tumor biology; functional alterations may precede morphologic abnormalities. In the oncologic population, especially in higher-risk patients, PET can be performed even when the nodules are smaller than 1 cm, because it might give an earlier characterization and, sometimes, could guide in the identification of alterations missed on CT.

Screening for lung cancer: challenges for the thoracic surgeon

Lung cancer is a global health burden and is among the most common and deadly of all malignancies worldwide. Early detection of resectable and potentially curable disease may reduce the overall death rate from lung cancer. However, at the present time, screening for lung cancer is not recommended by most clinical societies and health care agencies in the United States. This article discusses the history of, and rationale for, lung cancer screening, addresses optimization of screening protocols, and describes our current approach for the evaluation of small pulmonary nodules referred for surgical management.

Thoracic operations for pulmonary nodules are frequently not futile in patients with benign disease

INTRODUCTION

Pulmonary nodules often require operative resection to obtain a diagnosis. However, 10 to 30% of operations result in a benign diagnosis. Our purpose was to determine whether negative thoracic operations are futile by describing the pathological diagnoses; determining new diagnoses and treatment changes initiated based on operative findings; and assessing morbidity, mortality, and cost of the procedure.

METHODS

At our academic medical center, 278 thoracic operations were performed for known or suspected cancer between January 1, 2005, and April 1, 2009. We collected and summarized data pertaining to preoperative patient and nodule characteristics, pathologic diagnosis, postoperative treatment changes resulting from surgical resection, perioperative morbidity and mortality, and hospital charges for patients with benign pathology.

RESULTS

Twenty-three percent (65/278) of patients who underwent surgical resection for a suspicious nodule had benign pathology. We report granulomatous disease in 57%, benign tumors in 15%, fibrosis in 12%, and autoimmune and vascular diseases in 9%. Definitive diagnosis or treatment changes occurred in 85% of cases. Surgical intervention led to a new diagnosis in 69%, treatment course changes in 68% of benign cases, medication changes in 38%, new consultation in 31%, definitive treatment in 9%, and underlying disease management in 34%. There was no intraoperative, in-hospital, or 30-day mortality. Postoperative in-hospital events occurred in seven patients. The mean total cost was $25,515 with a mean cost per day of $7618.

CONCLUSIONS

Patients with a benign diagnosis after surgical resection for a pulmonary nodule received a new diagnosis or had a treatment course change in 85% of the cases.

The frequency and significance of radiologically detected indeterminate pulmonary nodules in patients with colorectal cancer

OBJECTIVE

To investigate the frequency and significance of pulmonary nodules in patients with colorectal cancer (CRC).

SUBJECTS AND METHODS

Medical records of 1,344 patients with CRC who underwent thoracic computerized tomography scans between January 2003 and December 2009 were reviewed. Those with any distant metastatic disease or who were already known to have pulmonary malignancies were excluded. Number, size, shape and location of the nodules were evaluated. A multivariate analysis was performed to determine the predictive factors for evidence of metastases.

RESULTS

Of the 1,344 patients, 55 (4.09%) had nodules that met the criteria of an indeterminate pulmonary nodule. The mean follow-up time was 25 ± 17.9 months and the mean time to develop pulmonary metastasis was 15.5 ± 6.4 months. The nodules of 17 (30.9%) patients showed progression at follow-up; 8 had metastasized. Multivariate analysis showed multiple indeterminate pulmonary nodules (p = 0.006) of parenchymal localization (p = 0.016) with an irregular border (p = 0.002), which is predictive of metastatic disease.

CONCLUSION

Our study has shown that multiple indeterminate pulmonary nodules with an irregular border in a parenchymal location were more likely to represent metastatic disease. However, the frequency of the occurrence of indeterminate pulmonary metastases of CRC was low.

Small peripheral lung adenocarcinoma: CT and histopathologic characteristics and prognostic implications

Since the introduction of computed tomography (CT), detection of small lung cancer, especially small peripheral adenocarcinoma, is common. Recently, the morphological characteristics, including thin-section CT and pathologic findings, and prognosis of small peripheral lung adenocarcinomas have been studied extensively. The radiologic and microscopic findings correlate well with each other and are closely associated with tumour prognosis. Most importantly, some subtypes of small lung adenocarcinomas with specific CT or pathologic features are curable. Therefore, all defining characteristics (CT, pathologic and prognostic) of this kind of tumour should be integrated to improve our understanding, provide guidelines for management and accurately assess its prognosis.

Evaluating the growth of pulmonary nodular ground-glass opacity on CT: comparison of volume rendering and thin slice images

This study examined the value of volume rendering (VR) interpretation in assessing the growth of pulmonary nodular ground-glass opacity (nGGO). A total of 47 nGGOs (average size, 9.5 mm; range, 5.7-20.6 mm) were observed by CT scanning at different time under identical parameter settings. The growth of nGGO was analyzed by three radiologists by comparing the thin slice (TS) CT images of initial and repeat scans with side-by-side cine mode. One week later synchronized VR images of the two scans were compared by side-by-side cine mode to evaluate the nGGO growth. The nodule growth was rated on a 5-degree scale: notable growth, slight growth, dubious growth, stagnant growth, shrinkage. Growth standard was defined as: Density increase ≥ 30 HU and (or) diameter increase (by 20% in nodules ≥ 10 mm, 30% in nodules of 5-9 mm). Receiver operating characteristic (ROC) was performed. The results showed that 32 nGGOs met the growth criteria (29 nGGOs showed an increase in density; 1 nGGO showed an increase in diameter; 2 nGGOs showed an increase in both diameter and density). Area under ROC curve revealed that the performance with VR interpretation was better than that with TS interpretation (P<0.01, P<0.05 and P<0.05 for observers A, B and C respectively). Consistency between different observers was excellent with both VR interpretation (κ=0.89 for observers A&C, A&B, B&C) and TS interpretation (κ=0.71 for A&B, κ=0.68 for A&C, κ= 0.74 for B&C), but time spending was less with VR interpretation than with TS interpretation (P<0.0001, P<0.0001 and P<0.05 for observers A, B and C, respectively). It was concluded that VR is a useful technique for evaluating the growth of nGGO.

Automated segmentation refinement of small lung nodules in CT scans by local shape analysis

One of the most important problems in the segmentation of lung nodules in CT imaging arises from possible attachments occurring between nodules and other lung structures, such as vessels or pleura. In this report, we address the problem of vessels attachments by proposing an automated correction method applied to an initial rough segmentation of the lung nodule. The method is based on a local shape analysis of the initial segmentation making use of 3-D geodesic distance map representations. The correction method has the advantage that it locally refines the nodule segmentation along recognized vessel attachments only, without modifying the nodule boundary elsewhere. The method was tested using a simple initial rough segmentation, obtained by a fixed image thresholding. The validation of the complete segmentation algorithm was carried out on small lung nodules, identified in the ITALUNG screening trial and on small nodules of the lung image database consortium (LIDC) dataset. In fully automated mode, 217/256 (84.8%) lung nodules of ITALUNG and 139/157 (88.5%) individual marks of lung nodules of LIDC were correctly outlined and an excellent reproducibility was also observed. By using an additional interactive mode, based on a controlled manual interaction, 233/256 (91.0%) lung nodules of ITALUNG and 144/157 (91.7%) individual marks of lung nodules of LIDC were overall correctly segmented. The proposed correction method could also be usefully applied to any existent nodule segmentation algorithm for improving the segmentation quality of juxta-vascular nodules.

Elastic phantoms generated by microfluidics technology: validation of an imaged-based approach for accurate measurement of the growth rate of lung nodules

This paper focuses on validating our approach for monitoring the development of lung nodules detected in successive chest low-dose computed tomography (LDCT) scans of a patient. Our methodology for monitoring detected lung nodules includes 3D LDCT data registration, which is a non-rigid technique and involves two steps: (i) global target-to-prototype alignment of one scan to another using the experience gained from a prior appearance model, followed by (ii) local alignment to correct for intricate relative deformations. We propose a new approach for validating the accuracy of our algorithm for elastic lung phantoms constructed with state-of-the-art microfluidics technology and in vivo data. Fabricated from a flexible transparent polymer, i.e. polydimethylsiloxane (PDMS), the phantoms mimic the contractions and expansions of the lung and nodules as seen during normal breathing. The in vivo data in our study had been collected from a small control group of four subjects and a larger test group of 27 subjects with known ground truth (biopsy diagnosis. The growth rate and diagnostic results for both phantoms and in vivo data confirm the high accuracy of our algorithm.

Recent technological and application developments in computed tomography and magnetic resonance imaging for improved pulmonary nodule detection and lung cancer staging

This review compares the emerging technologies and approaches in the application of magnetic resonance (MR) and computed tomography (CT) imaging for the assessment of pulmonary nodules and staging of malignant findings. Included in this review is a brief definition of pulmonary nodules and an introduction to the challenges faced. We have highlighted the current status of both MR and CT for the early detection of lung nodules. Developments are detailed in this review for the management of pulmonary nodules using advanced imaging, including: dynamic imaging studies, dual energy CT, computer aided detection and diagnosis, and imaging assisted nodule biopsy approaches which have improved lung nodule detection and diagnosis rates. Recent advancements linking in vivo imaging to corresponding histological pathology are also highlighted. In vivo imaging plays a pivotal role in the clinical staging of pulmonary nodules through TNM assessment. While CT and positron emission tomography (PET)/CT are currently the most commonly clinically employed modalities for pulmonary nodule staging, studies are presented that highlight the augmentative potential of MR.

Dose reduction strategies for thoracic multidetector computed tomography: background, current issues, and recommendations

This review will summarize the current background knowledge about radiation exposure related to thoracic computed tomography (CT). It will also review the historical development in this area. This will be followed by a summary of current efforts to reduce dose with respect to predefined clinical indications. Finally, the review will indicate future strategies for further dose reduction in thoracic CT imaging and give practical recommendations for everyday use.

Metastasis of gastric carcinoma to the thyroid and lung: a case report and review of literature

Cancer metastasis to the thyroid is extremely rare. The more commonly reported primary sites for metastasis to the thyroid are the kidney, breast, lung, colon, esophagus, and uterus. Thyroid metastasis from the stomach has only been reported in three cases. Herein, we report a 71-year-old man presenting with bilateral thyroid multinodular lesions. Bilateral near-total thyroidectomy was performed due to airway compression with related symptoms. Wedge resection of a suspicious pulmonary nodule, detected on CT, was performed for diagnosis. Polypoid lesions in the stomach were examined by trans-scopic biopsy. Poorly differentiated adenocarcinomas with the same histological profiles were noted at these three sites. The immunohistochemical staining for thyroglobulin of these specimens was negative. We conclude that a new thyroid mass appearing in a patient with present or prior malignancies should raise the concern of metastatic disease.

Pulmonary nodules in workers exposed to urban stressor

By multilayer spiral low-dose computed tomography (LD-CT) of the chest this study assesses the early detection of lung lesions on a sample of 100 traffic policemen of a big Italian city professionally exposed to urban pollutants and 100 controls non-occupationally exposed to urban pollutants matched by sex, age, length of service and cigarette smoking habit. Exposure to urban pollutants in traffic policemen was characterized using the annual average concentrations of PM(10), NO2 and benzene in the period 1998-2008 measured by fixed monitoring stations located in different areas of the city. A significant and increasing number of suspicious lung nodules with diameters between 5 and 10 mm was observed: in traffic policemen (including smokers and non-smokers) vs. controls (including smokers and non-smokers); in total smokers (including traffic policemen and controls) vs. total non-smokers (traffic policemen and controls); in smoker traffic policemen vs. smoker controls and vs. non-smoker traffic policemen; in non-smoker traffic policemen vs. non-smoker controls. The RR of finding cases with at least one lung nodule with diameters between 5 and 10mm in traffic policemen (including smokers and non-smokers) compared to controls (including smokers and non-smokers) is 1.94 (CI 1.13-3.31); in total smokers vs. non-smokers the RR is 1.96 (CI 1.20-3.19). The comparison between the interaction exposure and smoking shows an increase in smoker traffic policemen than in smoker controls (RR=2.14; CI 1.02-4.52). The RR for smoker traffic policemen was higher than in non-smoker traffic policemen (RR=2.09; CI 1.19-3.66). The results of our study show that: (1) while smoker workers have a higher risk for developing solid suspicious lung nodules, the simple routinely exposure to urban pollutants is unable to produce the same kind of increased risk; (2) the interaction of smoking and exposure to urban pollutants greatly increases the risk for the development of solid suspicious lung nodules. In conclusion, the use of chest LD-CT in workers at risk helps identify suspicious solid lung nodules at early stage.

Lung cancer screening

Lung cancer is the primary cause of cancer mortality in developed countries. First diagnosis only when disease has already reached the metastatic phase is the main reason for failure in treatment. To this regard, although low-dose spiral computed tomography (CT) has proven to be effective in the early detection of lung cancer (providing both higher resectability and higher long-term survival rates), the capacity of annual CT screening to reduce lung cancer mortality in heavy smokers has yet to be demonstrated. Numerous ongoing large-scale randomised trials are under way in high-risk individuals with different study designs. The initial results should be available within the next 2 years.

[Characterization and management of incidentally detected solitary pulmonary nodules]

How to deal with solitary pulmonary nodules (SPN) which are incidentally detected by computed tomography (CT) is an increasingly important task in the era of modern multislice CT. This paper reviews the morphological and functional characteristics and their value for discrimination between benign and malignant SPNs. In particular, the importance of nodule size, growth rate, margin morphology, density, calcifications or fatty components within the nodules, the significance of cavitations or aerobronchograms, enhancement patterns at dynamic contrast-enhanced CT and findings on positron emission tomography (PET) are discussed. The Bayesian analysis to calculate the probability of malignancy is presented. Finally, flow charts demonstrate the national and international recommendations for nodule management.

Improved detection of pulmonary nodules on energy-subtracted chest radiographs with a commercial computer-aided diagnosis software: comparison with human observers

OBJECTIVE

To retrospectively analyze the performance of a commercial computer-aided diagnosis (CAD) software in the detection of pulmonary nodules in original and energy-subtracted (ES) chest radiographs.

METHODS

Original and ES chest radiographs of 58 patients with 105 pulmonary nodules measuring 5-30 mm and images of 25 control subjects with no nodules were randomized. Five blinded readers evaluated firstly the original postero-anterior images alone and then together with the subtracted radiographs. In a second phase, original and ES images were analyzed by a commercial CAD program. CT was used as reference standard. CAD results were compared to the readers' findings. True-positive (TP) and false-positive (FP) findings with CAD on subtracted and non-subtracted images were compared.

RESULTS

Depending on the reader's experience, CAD detected between 11 and 21 nodules missed by readers. Human observers found three to 16 lesions missed by the CAD software. CAD used with ES images produced significantly fewer FPs than with non-subtracted images: 1.75 and 2.14 FPs per image, respectively (p = 0.029). The difference for the TP nodules was not significant (40 nodules on ES images and 34 lesions in non-subtracted radiographs, p = 0.142).

CONCLUSION

CAD can improve lesion detection both on energy subtracted and non-subtracted chest images, especially for less experienced readers. The CAD program marked less FPs on energy-subtracted images than on original chest radiographs.

Natural history of patients with subcentimeter pulmonary nodules undergoing hepatic resection for metastatic colorectal cancer

BACKGROUND

CT imaging frequently detects subcentimeter pulmonary nodules (SPN) in patients undergoing resection of colorectal cancer liver metastases. Their clinical significance is unknown.

STUDY DESIGN

Patients were identified who underwent hepatic resection for colorectal cancer liver metastases between October 2004 and March 2006. The presence and imaging features of preoperative SPN were analyzed for their association with progression-free survival (PFS), disease-specific survival (DSS), and SPN progression.

RESULTS

One hundred sixty patients underwent liver resection and 68 (43%) had SPN identified preoperatively. Median number of nodules was 1 (75(th) percentile: </=2 nodules) and median size of the largest was 3 mm (25(th) to 75(th) percentile: 2 to 5 mm). SPN were unilateral in 77%, calcified in 19%, solid in 92%, and smooth in contour in 95% of patients. At median follow-up of 31 months for survivors, SPN were proven to be metastatic disease in 35% of patients (24 of 68), either by radiographic increase in size or number (n = 12) or histologic confirmation after resection (n = 12). Median PFS for the 160 patients was 16 months and 3-year DSS was 78%. There was a trend toward shorter median PFS in patients with preoperative SPN compared with patients with no SPN (12 versus 20 months; p = 0.242). There was no difference in 3-year DSS (70% versus 83%; p = 0.46). SPN progression after hepatic resection did not substantially affect 3-year DSS. Calcified nodules were less likely to progress compared with noncalcified nodules (8% versus 42%; p = 0.03).

CONCLUSION

SPN are common among patients undergoing resection of colorectal cancer liver metastases and approximately one-third of these will prove to be metastatic disease. Presence of limited preoperative SPN might be associated with shorter PFS after hepatectomy, but does not substantially impact 3-year DSS, and should not necessarily preclude resection of hepatic metastases.

CT-Directed Microcoil Localization of Small Peripheral Lung Nodules: A Feasibility Study in Pigs

Platinum microcoils were placed in porcine lungs to determine the feasibility for use as a lung nodule marker. Using computed tomography (CT) guidance, the microcoils were successfully deployed in 17 out of 19 attempts. Coil deployment depth ranged from 7 mm to 34 mm below the pleural surface. Moderate pneumothorax was detected after 3 of 19 microcoil insertions. No hemothorax or significant pulmonary hemorrhage was noted. Fluoroscopic guided thoracoscopic resection was successful in 10 of 12 attempts. Platinum microcoils can be safely and easily deployed into the lung parenchyma with minimal complication risk, and can be used to guide subsequent thoracoscopic wedge resection.

Lung nodules: CT-guided placement of microcoils to direct video-assisted thoracoscopic surgical resection

PURPOSE

To prospectively assess the safety and effectiveness of computed tomography (CT)-guided placement of fiber-coated microcoils used to guide video-assisted thoracoscopic surgical (VATS) excision of small peripheral lung nodules, with successful excision as the primary outcome and successful CT-guided microcoil placement and procedural complications as secondary outcomes.

MATERIALS AND METHODS

The institutional review board approved the study protocol. Informed consent was obtained from all 69 enrolled patients (30 men, 39 women; mean age, 60.7 years +/- 10.1 [standard deviation]) with 75 nodules. At CT, one end of an 80-mm long, 0.018-inch-diameter fiber-coated microcoil was placed deep to the small peripheral lung nodule, and the other end was coiled in the pleural space. VATS excision of lung tissue, nodules, and the microcoil was performed with fluoroscopic guidance.

RESULTS

Seventy-three (97%) 4-24-mm nodules were successfully removed at fluoroscopically guided VATS excision; two nodules could not be removed. CT-guided microcoil placement was successful in all cases; however, two (3%) of 75 coils were displaced at VATS excision. Pneumothorax requiring chest tube placement occurred in two (3%) patients, and asymptomatic hemothorax occurred in one (1%) patient. The microcoil did not impede intraoperative frozen-section histopathologic analysis, which facilitated accurate clinical management in all patients. For 19 (28%) patients, the preoperative treatment plan based on bronchoscopy, needle biopsy, and positron emission tomography findings changed after VATS excision.

CONCLUSION

Microcoil localization of small peripheral lung nodules enabled fluoroscopically guided VATS resection of 97% of the nodules, with a low rate of intervention (3%) for procedural complications.

Clinical usefulness of the fluorodeoxyglucose (FDG)-PET maximal standardized uptake value (SUV) in combination with CT features for the differentiation of adenocarcinoma with a bronchioloalveolar carcinoma from other subtypes of non-small cell lung cancers

PURPOSE

To evaluate the clinical usefulness of fluorodeoxyglucose (FDG)-PET maximal SUV in combination with CT features for differentiation of adenocarcinoma with bronchioloalveolar carcinoma (BAC) from other subtypes of non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

This retrospective study included 125 patients (104 men and 21 women; mean age, 64 years) who underwent CT and subsequent FDG-PET examinations for preoperative evaluation and underwent curative intent operation with the final diagnoses of NSCLC made by surgical histopathology. We categorized NSCLC into adenocarcinoma with BAC feature and other subtypes. Finally, there were 16 cases of adenocarcinoma with BAC and 109 cases of other NSCLC subtypes included in the study. Several CT features of lung cancer were analyzed, including tumor size, presence of spiculation, margin (irregular or smooth), pattern of the mass (pure solid, pure ground glass opacity and mixed), associated pleural effusion and location (center, mid and periphery). Maximal SUV and visual scores of FDG uptakes of primary NSCLC were evaluated. The diagnostic performances of CT alone, PET alone, and combination of two modalities to predict adenocarcinoma with BAC from other subtypes of NSCLC were calculated.

RESULTS

A nodule with a mixed pattern with partly solid and ground glass opacity was significantly more frequent CT feature of an adenocarcinoma with BAC (8/16, 50%) as compared with the other subtypes (2/109, 1.8%) (p<0.0001). Maximal SUV of adenocarcinoma with BAC (mean=7.2) was significantly lower than that of other subtypes of NSCLC (mean=13.33) (p<0.0001). Sensitivity, specificity, PPV, and NPV of CT for differentiating adenocarcinoma with BAC from other subtypes was 50% (8/16), 98.2% (107/109), 80% (8/10), and 93% (107/115), respectively. Sensitivity, specificity, PPV, and NPV of FDG-PET was 68.8% (11/16), 86.2% (94/109), 42.3% (11/26), and 94.9% (94/99), respectively. Sensitivity, specificity, PPV, and NPV of combination of two modalities was 81.3% (13/16), 85.3% (93/109), 44.8% (13/29), 96.9% (93/96), respectively.

CONCLUSION

Careful combined assessment of the FDG-PET maximal SUV and CT findings have the potential to differentiate an adenocarcinoma with BAC from other NSCLC subtypes, such as a pure BAC. These findings might be useful for imaging interpretations and will help initial planning of NSCLC management.

Pulmonary ground-glass opacity (GGO) lesions-large size and a history of lung cancer are risk factors for growth

OBJECTIVE

Ground-glass opacity (GGO) of the lung is being frequently detected by thin section computed tomography scan. However, the long term management of detected GGO is still unclear. To establish follow-up plans, we performed the clinical and radiological review to identify the factors that are closely associated with GGO growth.

METHODS

We retrospectively analyzed computed tomography images of 125 GGOs that were stable for 3 months between 1999 and 2006 at the Cancer Institute Hospital, Tokyo. To identify factors that affect the roentgenological growth, the time to GGO growth curve by Kaplan-Meyer method was evaluated in terms of gender, age, smoking, initial size, existence of a solid part, GGO density, location, multiplicity, and lung cancer history by univariate and multivariate analyses.

RESULTS

The median observation period was 1048 days (177-3269) and 26 of 125 GGOs (21%) grew. The estimated growth population for 5 years was 30%. The growth was more frequently seen in the elderly (p = 0.017), in part-solid GGO (p < 0.01) and in GGO of larger than 10 mm (p < 0.01, logrank test). By multivariate analysis, initial size (p < 0.01, Cox's model) and history of lung cancer (p = 0.017, logistic model) were independent factors that were significantly associated with GGO growth. Fifty GGOs that were 10 mm or smaller and without a lung cancer history did not grow within 3.5 years.

CONCLUSIONS

After initial management and 3 month follow-up, larger size (more than 10 mm) and a history of lung cancer are risk factors for GGO growth, and therefore should be considered when making a follow-up plan.

[Low dose CT protocol--capability for early detection of lung carcinoma]

Lung carcinoma is the most common cause of death among men who died from cancer; also, among women, the incidence of this disease is on the increase. Use of multislice computed tomography (MSCT) has enhanced detection capability for pulmonary nodules. Nowadays, low radiation dose CT technique (LDCT) increases interest in lung cancer screening. This study is a part of the project whose aim is early diagnosis and well-timed treatment of lung carcinoma. Participants in this screening were above the age of 40, both smokers and non-smokers, who have undergone MSCT examination of lungs following low-dose protocol (LDCT). In the first ten months of the study, 375 volunteers have been examined. Overall number of detected nodules was 361; and 303 of these nodules have been characterized as non-calcificated. 95 participants (24.27%) had at least one non-calcificated nodule. 17 patients were referred to pulmologist and for further clinical evaluation. LDCT significantly increases detection of small, non-calcificated pulmonary nodules, and, therefore, gives higher opportunity to detect early lung carcinoma.

A novel needle-type sampling device for flexible ultrathin bronchoscopy

Diagnosis of suspected cancer in the periphery of the lung is difficult. A flexible ultrathin bronchoscope has been developed for the diagnosis of peripherally located pulmonary lesions that cannot be reached with the sampling devices for standard flexible bronchoscopes. The diagnostic yield with forceps and a brush for ultrathin bronchoscopes, however, is not adequate, especially when a lesion is not exposed to the bronchial lumen. We have thus developed a novel needle-type sampling device and tested its yield in transbronchial cytology. The device consists of an elongated dental H-file (0.4 mm in diameter and 110 cm in length), a housing sheath (1.0 mm in outer diameter), and a novel handle, which enables rapid out-and-in motion of the needle. Ten consecutive patients with a peripheral pulmonary lesion who had an indication for diagnostic procedure with a flexible ultrathin bronchoscope were enrolled. The optimal bronchial route to the lesion was analyzed with virtual bronchoscopy in a data set obtained with high-resolution computed tomography, and a novel bronchial route labeling system (prior-ridge-based relative orientation nomenclature) was employed to guide insertion of the bronchoscope. Sampling with the novel needle was performed prior to use of the forceps and brush under conventional fluoroscopy. In all the cases, sampling with the needle was successful and the amount of the specimen was sufficient for cytology. Our novel sampling system with flexible ultrathin bronchoscopes may contribute to accurate and minimally invasive diagnosis of peripheral pulmonary lesions.

The clinical significance of radiologically detected silent pulmonary nodules in early breast cancer

BACKGROUND

Increasing numbers of patients with early cancer undergo routine staging using computerized tomography (CT). Those in whom indeterminate pulmonary nodules are visualized without the presence of other metastatic lesions represent a clinical dilemma regarding their management as early breast cancer or metastatic disease.

PATIENTS AND METHODS

Medical records of breast cancer patients who underwent thoracic CT scans between the years 2002 and 2008 were analyzed. Those with obvious metastatic disease were excluded. Patients were identified via the radiology database by searching for the terms: 'suspicious lung metastases' and 'indeterminate nodules'.

RESULTS

Out of 1578 new patients assessed from 2002 to 2008, we carried out 802 staging CT scans. Thirty-four cases (4.2%) with indeterminate pulmonary nodules were identified. We categorized cases by size and number of nodules. At a median follow-up of 18 months, there were no changes in lesion size in 86% of patients with a solitary nodule <1 cm and 89% with multiple subcentimeter nodules. In contrast, in 100% of cases with pulmonary nodules >1 cm, the nodules had progressed at follow-up (chi(2), P = 0.004).

CONCLUSIONS

Breast cancer cases with subcentimeter indeterminate pulmonary lesions and no evidence of metastases elsewhere are unlikely to represent metastatic disease. Treatment with curative intent or entry into clinical trials should not be excluded.

Solitary pulmonary nodules and masses: a meta-analysis of the diagnostic utility of alternative imaging tests

The purpose was to assess the clinical utility of diagnostic tests for identifying malignancy within a solitary pulmonary nodule (SPN), and to create a nomogram or "look-up" table using clinical data and non-invasive radiology (positive) test results to estimate post-test probability of malignancy. Studies that examined computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET) and single photon emission computed tomography (SPECT) for the evaluation of SPN. Two reviewers independently abstracted data and assessed study quality. Study-specific and overall positive likelihood ratios (LRs) for each diagnostic test confirming a diagnosis of malignancy and negative LR for each diagnostic test excluding a diagnosis of malignancy within an SPN were calculated. Forty-four of 242 articles were included. Positive LRs for diagnostic tests were: CT 3.91 (95% confidence interval 2.42, 5.40), MRI 4.57 (3.03, 6.1), PET 5.44 (3.56, 7.32) and SPECT 5.16 (4.03, 6.30). Negative LRs were: CT 0.10 (0.03, 0.16), MRI 0.08 (0.03, 0.12), PET 0.06 (0.02, 0.09) and SPECT 0.06 (0.04, 0.08). Differences in performance for all tests were negligible; therefore, the clinician may confidently use any of the four tests presented in further evaluating an SPN. Given the low cost and prevalence of the technology, SPECT appears to be the leading choice for additional testing in SPN evaluation.

Diagnosis of solitary lung nodules using the local form of Ripley's K function applied to three-dimensional CT data

This paper analyzes the application of Ripley's K function to characterize lung nodules as malignant or benign in computerized tomography images. The proposed characterization method is based on a selection of measures from Ripley's K function to discriminate between benign and malignant nodules, using stepwise discriminant analysis. Based on the selected measures, a linear discriminant analysis procedure is performed once again in order to predict the classification of each nodule. To evaluate the ability of these features to discriminate the nodules, a set of tests was carried out using a sample of 39 pulmonary nodules, 29 benign and 10 malignant. A leave-one-out procedure was used to provide a less biased estimate of the linear discriminator's performance. The best setting of the analyzed function in the tested sample presented 70.0% of sensitivity but with 100.0% of specificity and 92.3% of accuracy. Thus, preliminary results of this approach are very promising regarding its contribution to the diagnosis of pulmonary nodules, but it still needs to be tested with larger series and associated to other quantitative imaging methods in order to improve global performance.

Pulmonary nodules discovered during the initial evaluation of pediatric patients with bone and soft-tissue sarcoma

BACKGROUND

Recent technical advances in CT imaging and data processing have improved the ability to detect small pulmonary nodules in children with bone and soft-tissue sarcoma undergoing radiologic imaging of the chest.

PROCEDURE

We retrospectively studied medical records and CT chest scans at initial diagnosis of 210 children and young adults presenting to a single pediatric tertiary care hospital specialized in oncology for evaluation of bone or soft-tissue sarcoma. We correlated clinical features and CT scan findings with patient outcome and histologic results, when available.

RESULTS

Pulmonary nodules (diameter </=3 cm) were identified in 66 patients (31.4%). The median size of the largest nodule in each patient was 5 mm (range, 1-20 mm). Of patients who underwent biopsy or resection of a nodule, 41.7% had metastatic pulmonary disease. Having more than three nodules and a bilateral distribution were associated with histology-proven metastasis (P = 0.002 and P = 0.011, respectively) and an increased frequency of recurrent or progressive metastatic disease in the lung (P < 0.001 and P = 0.023, respectively). Greater size of the largest nodule present showed a trend towards biopsy-proven lung metastasis, but did not reach statistical significance (P = 0.06). When biopsy or resection was not performed, increased size was significantly associated with nodules being presumed as malignant (median, 16.8 mm compared to 4.0 mm for biopsied nodules, P < 0.001).

CONCLUSIONS

Pulmonary nodules were commonly detected during the initial evaluation of pediatric cases of sarcoma. Number and distribution of nodules were significantly associated with metastatic disease and outcome.

How to deal with incidentally detected pulmonary nodules less than 10mm in size on CT in a healthy person

The high frequency of non-calcified pulmonary nodules (NCN) <10mm incidentally detected on a multi-detector CT (MDCT) of the chest raises the question of how clinicians and radiologists should deal with these nodules. Management algorithms for solitary pulmonary nodules >10mm do not carry across to sub-centimeter lesions. Purpose of this review is to provide a 10-step approach for routinely detected sub-centimeter NCN on a MDCT in healthy persons in order to be able to make an optimal discrimination between benign and malignant NCNs. Recommendations are primarily based on individual cancer risk, the presence or absence of calcifications and nodule size. In nodules >4-5mm nodule consistency, margin and shape should be taken into account. Next steps in the nodule evaluation are the assessment of localization, nodule number, presence or absence of growth and volume doubling time. Growth is defined as a volume doubling time of 400 days or less, based on volumetry. For nodules <4mm, a follow-up CT at 12 months is recommended in high risk persons, whilst for low-risk persons no follow-up is needed. If no growth is observed at 12 months, no further follow-up is required. For solid, smooth or attached indeterminate NCN between 5 and 10mm we recommend an annual repeat scan, whilst for purely intra-parenchymal nodules a 3-month repeat scan should be made to assess growth. Growing lesions with a volume doubling time <400 days require further work-up and diagnosis, otherwise an annual repeat scan to assess growth is recommended.

Neodymium:yttrium-aluminium-garnet laser for excision of pulmonary nodules: an institutional review

Eighty patients amongst 850 undergoing pulmonary surgery with the use of neodymium:yttrium-aluminium-garnet (Nd:YAG) laser had a solitary pulmonary nodule (< or = 50 mm) on chest radiography, which was confirmed or suspected pre-operatively to be primary lung cancer. All patients had a mini-thoracotomy to expose the lesion. They then had Nd:YAG laser to excise the nodule locally. There was no hospital mortality. Six patients had non-fatal post-operative complications. Pathologically, 46 patients had primary lung cancer and ten had secondary lung cancer. Twenty-four others had benign lesions. Mean hospital stay was 5.5 days. Post-operative reduction of forced vital capacity (FVC) and forced expiratory volume in one second (FEV(1)) was 14% and 13% (mean), respectively. Thirty-seven patients with primary lung cancer were followed up for between 12 months and 60 months. Mean survival time of these patients was 39 months (s.d. 13 months). It was concluded that Nd:YAG laser for pulmonary nodular lesions should be considered for a selected group of patients unsuitable for standard resection.

Necrotizing granuloma of the lung: imaging characteristics and imaging-guided diagnosis

OBJECTIVE

The purpose of this study was to assess CT findings and the sensitivities of imaging-guided fine-needle aspiration (FNA) biopsy and core needle biopsy in the diagnosis of necrotizing granuloma of the lung.

CONCLUSIONS

The CT characteristics of necrotizing granuloma are indistinguishable from those of malignant tumors; tissue diagnosis therefore is necessary. Core needle biopsy is a sensitive method for diagnosing necrotizing granuloma of the lung, but FNA biopsy is insufficient for diagnosis.

The role of VATS for staging and diagnosis in patients with non-small cell lung cancer

Video-assisted thoracoscopic surgery is an effective and versatile tool for the diagnosis and staging of patients with lung cancer. Despite advances in imaging technology, including integrated positron emission tomography/computed tomography scans, the clinical staging of patients with lung cancer remains inaccurate. Tissue confirmation is critical for accurate staging and treatment of patients with lung cancer. Thoracoscopy is an excellent and often preferred approach to the biopsy of inferior mediastinal, anteroposterior window, and para-aortic lymph nodes, and has the added advantage of allowing simultaneous assessment of the pleural space, satellite lung nodules, and T status of the tumor. Thoracoscopic wedge resection is the preferred technique for diagnosing indeterminate solitary pulmonary nodules. In the era of computed tomography screening, most indeterminate lung nodules are less than 1 cm in size and pose unique challenges in determining malignant potential and obtaining a tissue diagnosis. Several techniques have been adopted to allow successful thoracoscopic biopsy of these subcentimeter lung nodules.

Interobserver-variability of lung nodule volumetry considering different segmentation algorithms and observer training levels

OBJECTIVE

The aim of this study was to investigate the interobserver variability of CT based diameter and volumetric measurements of artificial pulmonary nodules. A special interest was the consideration of different measurement methods, observer experience and training levels.

MATERIALS AND METHODS

For this purpose 46 artificial small solid nodules were examined in a dedicated ex-vivo chest phantom with multislice-spiral CT (20 mAs, 120 kV, collimation 16 mm x 0.75 mm, table feed 15 mm, reconstructed slice thickness 1mm, reconstruction increment 0.7 mm, intermediate reconstruction kernel). Two observer groups of different radiologic experience (0 and more than 5 years of training, 3 observers each) analysed all lesions with digital callipers and 2 volumetry software packages (click-point depending and robust volumetry) in a semi-automatic and manually corrected mode. For data analysis the variation coefficient (VC) was calculated in per cent for each group and a Wilcoxon test was used for analytic statistics.

RESULTS

Click-point robust volumetry showed with a VC of <0.01% in both groups the smallest interobserver variability. Between experienced and un-experienced observers interobserver variability was significantly different for diameter measurements (p=0.023) but not for semi-automatic and manual corrected volumetry. A significant training effect was revealed for diameter measurements (p=0.003) and semi-automatic measurements of click-point depending volumetry (p=0.007) in the un-experienced observer group.

CONCLUSIONS

Compared to diameter measurements volumetry achieves a significantly smaller interobserver variance and advanced volumetry algorithms are independent of observer experience.

Incidentally discovered tumors of the endocrine glands

Clinically inapparent masses, or ‘incidentalomas’ of the endocrine glands are increasingly common owing to continued advancements in medical imaging. Incidentalomas of the adrenal glandS have received substantial attention in the literature, whereas lesions of the thyroid and endocrine pancreas, though frequently encountered in the clinic, have received relatively little attention. We review the detection and subsequent management of incidentalomas of the thyroid, adrenal and pancreas, with specific attention paid to the mode of detection and risk stratification of lesions.

Detección y caracterización del nódulo pulmonar por tomografía computarizada multicorte

Pulmonary nodules are a common finding in routine chest studies. Although there are no pathognomic clinical or radiological signs that enable the exact nature of a pulmonary nodule to be determined, the clinical context and the appropriate characterization of the pulmonary nodule make it possible to reach the correct diagnosis in most cases. This article discusses the most important aspects involved in the use of multislice computed tomography in the noninvasive detection and characterization of pulmonary nodules.