Management strategies for the solitary pulmonary nodule

Lung microwave ablation: Post-procedure imaging features and evolution of pulmonary ground-glass nodule-like lung cancer

PURPOSE

To retrospectively examine the imaging characteristics of chest-computed tomography (CT) following percutaneous microwave ablation (MWA) of the ground-glass nodule (GGN)-like lung cancer and its dynamic evolution over time.

MATERIALS AND METHODS

From June 2020 to May 2021, 147 patients with 152 GGNs (51 pure GGNs and 101 mixed GGNs, mean size 15.0 ± 6.3 mm) were enrolled in this study. One hundred and forty-seven patients underwent MWA procedures. The imaging characteristics were evaluated at predetermined time intervals: immediately after the procedure, 24-48 h, 1, 3, 6, 12, and ≥18 months (47 GGNs).

RESULTS

This study population included 147 patients with 152 GGNs, as indicated by the results: 43.5% (66/152) adenocarcinoma in situ, 41.4% (63/152) minimally invasive adenocarcinoma, and 15.1% (23/152) invasive adenocarcinoma. Immediate post-procedure tumor-level analysis revealed that the most common CT features were ground-glass opacities (93.4%, 142/152), hyperdensity within the nodule (90.7%, 138/152), and fried egg sign or reversed halo sign (46.7%, 71/152). Subsequently, 24-48 h post-procedure, ground-glass attenuations, hyperdensity, and the fried egg sign remained the most frequent CT findings, with incidence rates of 75.0% (114/152), 71.0% (108/152), and 54.0% (82/152), respectively. Cavitation, pleural thickening, and consolidation were less frequent findings. At 1 month after the procedure, consolidation of the ablation region was the most common imaging feature. From 3 to 12 months after the procedure, the most common imaging characteristics were consolidation, involutional parenchymal bands and pleural thickening. At ≥18 months after the procedure, imaging features of the ablation zone revealed three changes: involuting fibrosis (80.8%, 38/47), consolidation nodules (12.8%, 6/47), and disappearance (6.4%, 3/47).

CONCLUSIONS

This study outlined the anticipated CT imaging characteristics of GGN-like lung cancer following MWA. Diagnostic and interventional radiologists should be familiar with the expected imaging characteristics and dynamic evolution post-MWA in order to interpret imaging changes with a reference image.

Comprehensive plasma metabolomics and lipidomics of benign and malignant solitary pulmonary nodules

INTRODUCTION

Solitary pulmonary nodules (SPNs) are commonly found in imaging technologies, but are plagued by high false-positive rates.

OBJECTIVE

We aimed to identify metabolic alterations in SPN etiology and diagnosis using less invasive plasma metabolomics and lipidomics.

METHODS

In total, 1160 plasma samples were obtained from healthy volunteers (n = 280), benign SPNs (n = 157) and malignant SPNs (stage I, n = 723) patients enrolled from 5 independent centers. Gas chromatography-triple quadrupole mass spectrometry (GC‒MS) and liquid chromatography-Q Exactive Hybrid Quadrupole-Orbitrap mass spectrometry (LC‒MS) were used to analyze the samples for untargeted metabolomics and lipidomics.

RESULTS AND CONCLUSION

GC‒MS-based metabolomics revealed 1336 metabolic features, while LC‒MS-based lipidomics revealed 6088 and 2542 lipid features in the positive and negative ion modes, respectively. The metabolic and lipidic characteristics of healthy vs. benign or malignant SPNs exhibited substantial pattern differences. Of note, benign and malignant SPNs had no significant variations in circulating metabolic and lipidic markers and were validated in four other centers. This study demonstrates evidence of early metabolic alterations that can possibly distinguish SPNs from healthy controls, but not between benign and malignant SPNs.

Management of Incidentalomas

Incidental findings are common in the evaluation of surgical patients. Understanding the appropriate assessment and management of these frequent occurrences is important for the provision of comprehensive quality care. This review details the epidemiology, considerations, and recommendations for management of common incidental manifestations in surgical patients, including Meckel diverticulum, adrenal incidentaloma, thyroid nodule, solitary pulmonary nodule, small bowel intussusception, gallstones, and incidental appendectomy.

Características clinicopatológicas de nódulos pulmonares: Experiencia en Clínica Reina Sofía, Bogotá, Colombia

Introducción. El cáncer de pulmón es la primera causa de mortalidad por cáncer a nivel mundial, lo que hace que sea considerado un problema de salud pública. Existen diferentes hallazgos imagenológicos que hacen sospechar la presencia de cáncer de pulmón, uno de los cuales son los nódulos pulmonares; sin embargo, estos también pueden verse en entidades benignas. Métodos. Se incluyeron 66 pacientes con biopsia de nódulo pulmonar en la Clínica Reina Sofía, en la ciudad de Bogotá, D.C., Colombia, entre el 1° de marzo del 2017 y el 28 de febrero del 2020. Se analizaron las características demográficas de los pacientes, las características morfológicas e histopatológicas de los nódulos pulmonares y la correlación entre sus características imagenológicas e histopatológicas. Resultados. El 69,2 % de los nódulos estudiados tenían etiología maligna, de estos el 55,5 % era de origen metástasico y el 44,5 % eran neoplasias primarias de pulmón, con patrón sólido en el 70,6 % de los casos. El patrón histológico más frecuente fue adenocarcinoma. Respecto a las características radiológicas, en su mayoría los nódulos malignos medían de 1 a 2 cm, de morfología lisa y distribución múltiple, localizados en lóbulos superiores. Conclusiones. La caracterización de los nódulos pulmonares brinda información relevante que orienta sobre los diagnósticos más frecuentes en nuestro medio, cuando se estudian nódulos sospechosos encontrados incidentalmente o en el seguimiento de otro tumor. Como el nódulo es la manifestación del cáncer temprano del pulmón, establecer programas de tamización que permitan el diagnóstico oportuno, es hoy día una imperiosa necesidad, para reducir la mortalidad.

Factors associated with subcentimeter pulmonary nodule outcomes followed with computed tomography imaging in oncology patients

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PNs with irregular, lobuled or spiculated margins exhibited faster growth than PNs with regular, smooth margins.

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Malignancy was significantly associated with male gender, a colorectal cancer diagnosis and advanced stage disease.

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Oncologic patients should have an individualized CT follow-up strategy, as the rate of malignant pulmonary nodules is higher than in the general population.

Introduction

Technological advancements in computed tomography (CT) have enabled the frequent detection of small pulmonary nodules (PNs), especially in patients with an oncologic history. It is important the malignant versus benign etiology of PNs be determined. The aim of the present study was to evaluate the behavior and clinical/radiological characteristics of subcentimeter PNs detected by CT in oncologic patients.

Methods

An observational, longitudinal, retrospective and single-center study was conducted with a sample of 100 patients with a diagnosis of a primary malignant solid tumor outside of the lungs who developed indeterminate subcentimeter PNs (n = 251) detected on consecutive thoracic CT scans from 2015 to 2017. Follow-up CTs for each patients were examined in each of three periods (0–3 months, 3–6 months, and 6 months to 1 year).

Results

In our study sample, 28 patients (28 %) showed one or more signs suspicious of pulmonary metastasis, including ≥50 % PN growth, nodule growth followed by size reduction in patients undergoing chemotherapy, and the appearance of multiple nodules. The majority (56 %) of the PNs were detected during the 3–6-month follow-up CT scan. PNs with irregular, lobuled, or spiculated margins exhibited faster growth than PNs with regular, smooth margins. Malignancy of PNs was found to be significantly associated with being male, a primary colorectal cancer diagnosis, and advanced stage disease.

Conclusion

Our findings reinforce the necessity of an individualized CT follow-up strategy for patients with an oncologic history, as well as the importance of early nodule screening, with the inter-scan interval being dependent on the primary neoplasm.

Ectopic intrapulmonary follicular adenoma diagnosed by surgical resection

Ectopic intrapulmonary thyroid tissue is extremely rare and considerably difficult to diagnose without surgery. Ectopic thyroid tissue, described as a mediastinal tumor, and intrapulmonary lesions are infrequent. An abnormal shadow was detected upon chest X-ray in a 60-year old woman with a history of benign thyroid goiter. A computed tomography scan revealed a solitary nodule measuring 27 mm in diameter in the left lower lobe, the diameter of which had increased by 5 mm since initial observation eight years ago. A thoracoscopic wedge resection was performed and the lesion was determined to be a non-invasive, soft-tissue tumor. It was pathologically diagnosed as an ectopic thyroid follicular adenoma. The course of the tumor was uneventful. A diagnosis of ectopic intrapulmonary thyroid should be made cautiously and only after ruling out metastasis of a follicular adenoma or thyroid carcinoma. This diagnosis of ectopic thyroid tissue was made possible by the surgical approach.

SPNsim: A database of simulated solitary pulmonary nodule PET/CT images facilitating computer aided diagnosis

The aim of the present work was to design and develop a database of simulated solitary pulmonary nodules (SPN) in pairs of computed tomography (CT) and positron emission tomography (PET) images, using Monte Carlo (MC) simulation methods. We have developed an SPN image modeling pipeline to feed the database entitled SPNsim. The database is web-accessible and it is contains two subsets of simulated PET/CT SPN images. The first subset is currently composed of 1000 cases containing pairs of the transaxial CT and the corresponding PET slice with various types of simulated SPNs, presented as individual records. The second subset contains pairs of the transaxial CT and the corresponding PET slice of simulated SPNs, presenting cases of graded difficulty in diagnosis. The users of the database will have the ability to set queries in order to retrieve cases with certain characteristics, as well as characterized image sets. All images are freely available and may be downloaded from the website. SPNsim provides a useful reference data set for training and evaluation of computer aided detection (CAD) and diagnosis (CADx) systems focusing on SPN.

Comparison of Renal Cell Carcinoma Surveillance Guidelines: Competing Trade-Offs

PURPOSE

We estimated the differences in intensity, cost, radiation exposure and cancer control of published surveillance guidelines screening for secondary renal cell carcinoma in patients treated with partial nephrectomy.

MATERIALS AND METHODS

We developed a Monte Carlo simulation model to contrast the existing guidelines in terms of cost, radiation exposure and cancer control. Model inputs were extrapolated from the existing literature. Surveillance guidelines were analyzed from the AUA, CUA, EAU and NCCN®. Risk stratification among patients treated with partial nephrectomy was based on tumor characteristics.

RESULTS

Expected costs during the 5 years after partial nephrectomy were $587 (CUA), $1,076 (AUA), $1,705 (EAU) and $1,768 (NCCN) for low risk patients, and $903 (CUA), $2,525 (EAU) and $3,904 (AUA and NCCN) for high risk patients. Radiation exposure ranged from 31.41 mSv (CUA) to 104.34 mSv (NCCN) for low risk patients and 46.88 mSv (CUA) to 231.61 mSv (AUA and NCCN) for high risk patients. The EAU and CUA guidelines led to the diagnosis of the highest percentage of low risk patients (more than 95%) while all guidelines diagnosed more than 92% of high risk patients with recurrence.

CONCLUSIONS

Renal cell carcinoma surveillance guidelines differ greatly in terms of intensity, cost and radiation exposure. It is important for clinicians to adopt standardized surveillance strategies that limit unnecessary cost and radiation exposure without compromising cancer control.

The usefulness of combined diagnostic CT and (99m)Tc-octreotide somatostatin receptor SPECT/CT imaging on pulmonary nodule characterization in patients

The objective of this study was to evaluate the clinical value of combination of diagnostic computed tomography (CT) and somatostatin receptor imaging with (99m)Tc-octreotide acetate SPECT/CT in differentiation of benign pulmonary nodules from cancers.

METHODS

This was a retrospective study, 29 patients with suspected pulmonary neoplasm underwent diagnostic CT and (99m)Tc-octreotide SPECT/CT scans, and the tumor-to-normal tissue tracer value (T/N) for (99m)Tc-octreotide was measured. Diagnosis was confirmed by histological analysis.

RESULTS

Eighteen of the 29 patients included in this study had lung cancer: 2 with small cell lung cancer and 16 with nonsmall cell lung cancer. The other 11 patients had benign lung lesions: 5 with tuberculosis, 4 with nontuberculosis infection, 1 with hematoma, and 1 with fibroma. (99m)Tc-octreotide uptake (expressed as mean T/N±SD) was significantly higher in lung cancers (2.58±0.91) than benign lesions (1.38±0.79) (p=0.002). Specificity for pulmonary malignant nodule diagnosis was 63.6% for diagnostic CT, 72.7% for somatostatin receptor SPECT/CT imaging, and 81.8% for the combined use of diagnostic CT and somatostatin receptor SPECT/CT imaging.

CONCLUSION

Somatostatin receptor imaging with (99m)Tc-octreotide SPECT/CT is useful for the differentiation of benign pulmonary nodules from lung cancers, the combination of diagnostic CT and (99m)Tc-octreotide SPECT/CT further increases the specificity of malignant pulmonary nodule detection.

Mini-invasive diagnosis and synchronous treatment of solitary pulmonary nodule

Aim:

to develop a simplified method to make a rapid, cost-effective, and precise diagnosis of solitary pulmonary nodules, and to perform synchronous treatment of solitary pulmonary nodules.

Methods:

the solitary pulmonary nodule was located by digital palpation, and tissue was acquired with a core biopsy gun. In the presence of primary lung cancer, the intervention proceeded to lobectomy. In the case of a benign assessment, the whole nodule was wedged out and sent for a frozen-section double check: if the benign assessment was confirmed, the patient was excluded from further surgery; if the assessment was revised to malignant, the intervention proceeded to lobectomy as well as lymphadenectomy.

Results:

76 patients were enrolled. The mean nodule diameter was 1.8 ± 0.6 cm, the mean distance between the visceral pleural and the nodule was 2.4 ± 1.4 cm, and the mean number of punctures was 2.5. The mean time for the phase of intraoperative core biopsy was 10 ± 2 min, and the related blood loss was approximately 5 mL. Fifty-six malignant nodules and 20 benign nodules were confirmed. Both the sensitivity and accuracy were 100%.

Conclusion:

our results indicate that the simplified mini-invasive diagnosis and treatment is an accurate, safe, rapid, and cost-saving method, which may translate into fundamentally reducing the medical cost and time for lung cancer patients.

Navigational bronchoscopy with biopsy versus computed tomography-guided biopsy for the diagnosis of a solitary pulmonary nodule: a cost-consequences analysis

BACKGROUND

Solitary pulmonary nodules (SPNs) are frequent and can be malignant. Both computed tomography-guided biopsy and electromagnetic navigational bronchoscopy (ENB) with biopsy can be used to diagnose a SPN. A nondiagnostic computed tomography (CT)-guided or ENB biopsy is often followed by video-assisted thoracoscopic surgery (VATS) biopsy. The relative costs and consequences of these strategies are not known.

METHODS

A decision tree was created with values from the literature to evaluate the clinical consequences and societal costs of a CT-guided biopsy strategy versus an ENB biopsy strategy for the diagnosis of a SPN. The serial use of ENB after nondiagnostic CT-guided biopsy and CT-guided biopsy after nondiagnostic ENB biopsy were tested as alternate strategies.

RESULTS

In a hypothetical cohort of 100 patients, use of the ENB biopsy strategy on average results in 13.4 fewer pneumothoraces, 5.9 fewer chest tubes, 0.9 fewer significant hemorrhage episodes, and 0.6 fewer respiratory failure episodes compared with a CT-guided biopsy strategy. ENB biopsy increases average costs by $3719 per case and increases VATS rates by an absolute 20%. The sequential diagnostic strategy that combines CT-guided biopsy after nondiagnostic ENB biopsy and vice versa decreases the rate of VATS procedures to 3%. A sequential approach starting with ENB decreases average per case cost relative to CT-guided biopsy followed by VATS, if needed, by $507; and a sequential approach starting with CT-guided biopsy decreases the cost relative to CT-guided biopsy followed by VATS, if needed, by $979.

CONCLUSIONS

An ENB with biopsy strategy is associated with decreased pneumothorax rate but increased costs and increased use of VATS. Combining CT-guided biopsy and ENB with biopsy serially can decrease costs and complications.

Lung cancer screening: making the transition from research to clinical practice

PURPOSE OF REVIEW

The purpose of this review is to examine the literature on lung cancer screening with an emphasis on the prevalence of cancer in screen-detected nodules. On the basis of the evidence, we will then develop a practical approach to screen-detected lung nodules.

RECENT FINDINGS

The first large randomized controlled trial using low-dose computed tomography (LDCT) found that persons undergoing three annual screening examinations with LDCT had a 20% relative reduction in lung cancer mortality as compared with those screened with annual chest X-rays. The probability of cancer in screen-detected nodules depends on their size and whether the nodules are detected on prevalence or incidence screens. The probability of cancer in screen-detected nodules ranges from 2.4 to 5.2%. Management strategies for screen-detected nodules that have been used successfully include careful observation using serial CT imaging, CT-guided fine needle biopsy, and surgery in carefully selected cases. The most frequently used strategies involve serial CT imaging and CT-guided biopsy for larger nodules and those that demonstrate growth on follow-up.

SUMMARY

There is now evidence that LDCT in carefully selected high-risk populations can lead to better outcomes but the cost effectiveness of mass screening with LDCT is still unknown. Only patients at high risk for cancer should be screened.

Decision making in patients with pulmonary nodules

Integrating current evidence with fundamental concepts from decision analysis suggests that management of patients with pulmonary nodules should begin with estimating the pretest probability of cancer from the patient's clinical risk factors and computed tomography characteristics. Then, the consequences of treatment should be considered, by comparing the benefits of surgery if the patient has lung cancer with the potential harm if the patient does not have cancer. This analysis determines the "treatment threshold," which is the point around which the decision centers. This varies widely among patients depending on their cardiopulmonary reserve, comorbidities, and individual preferences. For patients with a very low probability of cancer, careful observation with serial computed tomography is warranted. For those with a high probability of cancer, surgical diagnosis is warranted. For patients in the intermediate range of probabilities, either computed tomography-guided fine-needle aspiration biopsy or positron emission tomography, possibly followed by computed tomography-guided fine-needle aspiration biopsy, is best. Patient preferences should be considered because the absolute difference in outcome between strategies may be small. The optimal approach to the management of patients with pulmonary nodules is evolving as technologies develop. Areas of uncertainty include quantifying the hazard of delayed diagnosis; determining the optimal duration of follow-up for ground-glass and semisolid opacities; establishing the roles of volumetric imaging, advanced bronchoscopic technologies, and limited surgical resections; and calculating the cost-effectiveness of different strategies.

[Clinical application of CT-guided preoperative pulmonary nodule localization technique]

背景与目的

胸腔镜术中对于直径 < 1 cm的肺小结节较难准确定位。数年前即有学者开始尝试使用各种方法进行术前的肺小结节定位。本文从适应症、结果、并发症三个方面回顾性分析了胸腔镜术前CT引导下Hook-wire定位的临床应用价值。

方法

2010年1月-2010年4月，20例患者于胸腔镜术前接受了CT引导下肺小结节Hook-wire定位。小结节直径从0.5 cm-2 cm（平均9.8 cm±5.3 cm）。评价指标包括定位成功率，定位相关并发症，中转开胸比率等。

结果

20例患者中18例定位成功，CT定位花费时间平均为14.5 min，全组无严重并发症发生。

结论

胸腔镜术前CT引导下肺小结节Hook-wire定位有一定的临床应用价值，可帮助术中精确定位肺小结节位置，并且并发症发生率较低。

Surgical resection of highly suspicious pulmonary nodules without a tissue diagnosis

OBJECTIVE

The safety and efficacy of surgical resection of lung nodule without tissue diagnosis is controversial. We evaluated direct surgical resection of highly suspicious pulmonary nodules and the clinical and radiological predictors of malignancy.

METHODS

Retrospective analyses were performed on 113 patients who underwent surgical resection without prior tissue diagnosis for highly suspicious pulmonary nodules. Clinical and radiological characteristics were compared between histologically proven benign and malignant nodules after resection. Total costs, length of hospitalization and waiting time to surgery were compared with those of patients who had tissue diagnosis prior to surgery.

RESULTS

Among 280 patients with pulmonary nodules suspicious for lung cancer, 113 (40.4%) underwent operation without prior tissue diagnosis. Lung nodules were diagnosed as malignant in 96 (85%) of the 113 patients. Except for forced expiratory volume in 1 s, clinical characteristics were not significantly different according to the pathologic results. Forty-five (90%) of 50 patients with ground-glass opacity nodules had a malignancy. Mixed ground-glass opacity, bubble lucency, irregular margin and larger size correlated with malignancy in ground-glass opacity nodules (P<0.05). Fifty-one (81%) of 67 patients with solid nodules had a malignancy. Spiculation, pre-contrast attenuation and contrast enhancement significantly correlated with malignancy in solid nodules (P<0.05). Surgical resection without tissue diagnosis significantly decreased total costs, hospital stay and waiting time (P<0.05).

CONCLUSIONS

Direct surgical resection of highly suspicious pulmonary nodules can be a valid procedure. However, careful patient selection and further investigations are required to justify direct surgical resection.

Second primary lung carcinoma in patients with first primary breast carcinoma: two case reports and review of the literature

Introduction

Patients undergoing complete treatments of breast carcinoma can be found with pulmonary nodules during the follow up period. Either metastasis from breast carcinoma or second primary bronchogenic carcinoma should be considered as a possible diagnosis.

Case presentations

Two female patients with ages of 66 and 64, underwent modified radical mastectomy for breast carcinoma 5 and 2 years ago, were found with single pulmonary nodule, 1.0 cm and 0.8 cm from the left lower and right upper lobe. There was no other site of metastasis being noted after systemic survey.

Wedge resections through video assisted thoracic surgery were performed and one of them underwent lobectomy and mediastinal lymph node dissection after the primary lung carcinoma being proved pathologically (thyroid transcription factor 1 and cytokeratin 7 positive). The dissected lymph node in this patient is negative for malignancy. They underwent low dose chemotherapy postoperatively because of increased risk of tumor occurrence for these patients. Patients with smoking or irradiation history usually favor the diagnosis of second primary lung carcinoma. However, these two treated breast carcinoma cases, which didn’t have smoking or irradiation history, developed second primary lung carcinomas. It is relatively rare reported before.

Conclusions

Pulmonary nodules in patients with prior breast carcinomas were usually regarded as metastatic lesions. However, the possibility of second primary still cannot be excluded, especially to the solitary type. Video assisted thoracic surgery can provide early and accurate diagnosis as well as effective treatment.

Does the availability of positron emission tomography modify diagnostic strategies for solitary pulmonary nodules? An observational study in France

Background

Previous studies showed that at the individual level, positron emission tomography (PET) has some benefits for patients and physicians in terms of cancer management and staging. We aimed to describe the benefits of (PET) in the management of solitary pulmonary nodules (SPNs) in a population level, in terms of the number of diagnostic and invasive tests performed, time to diagnosis and factors determining PET utilization.

Methods

In an observational study, we examined reports of computed tomography (CT) performed and mentioning "spherical lesion", "nodule" or synonymous terms. We found 11,515 reports in a before-PET period, 2002–2003, and 20,075 in an after-PET period, 2004–2005. Patients were followed through their physician, who was responsible for diagnostic management.

Results

We had complete data for 112 patients (73.7%) with new cases of SPN in the before-PET period and 250 (81.4%) in the after-PET period. Patients did not differ in mean age (64.9 vs. 64.8 years). The before-PET patients underwent a mean of 4 tests as compared with 3 tests for the after-PET patients (p = 0.08). Patients in the before-PET period had to wait 41.4 days, on average, before receiving a diagnosis as compared with 24.0 days, on average, for patients in the after-PET period who did not undergo PET (p < 0.001). In the after-PET period, 11% of patients underwent PET during the diagnostic process. A spiculated nodule was more likely to determine prescription for PET (p < 0.001). Multivariate analysis revealed that patients in both periods underwent fewer tests when PET was prescribed by general practitioners (p < 0.001) and if the nodule was not spiculated (p < 0.001). The proportion of unnecessary invasive approaches prescribed (47% vs. 49%) did not differ between the groups.

Conclusion

In our study, 1 year after the availability of PET, the technology was not the first choice for diagnostic management of SPN. Even though we observed a tendency for reduced number of tests and mean time to diagnosis with PET, these phenomena did not fully relate to PET availability in health communities. In addition, the availability of PET in the management of SPN diagnosis did not reduce the overall rate of unnecessary invasive approaches.

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.

Lung cancer

Lung cancer is the most frequently occurring cancer in the world, and in the United States it is the second most common cancer diagnosed. Accurate staging by imaging can have a significant impact on appropriate treatment and surgical options. Familiarity with the different histologic subtypes of lung cancer and the typical and atypical appearances of lung cancer is vital. Radiologists serve a critical role in the diagnosis, staging, and follow-up of patients with lung cancer.

Distinguishing benign from malignant pulmonary nodules with helical chest CT in children with malignant solid tumors

PURPOSE

To retrospectively assess whether computed tomographic (CT) findings can indicate the benign or malignant nature of pulmonary nodules in pediatric patients with malignant solid primary tumors.

MATERIALS AND METHODS

With institutional review board approval, waived parental and patient consent, and HIPAA compliance, the authors determined the incidence of malignancy among 81 pulmonary nodules that were sampled at biopsy within 3 weeks after chest CT (January 1999 to September 2003) in 41 young patients with malignant solid tumors. Three radiologists independently and retrospectively reviewed these scans and the available previously obtained scans, classifying nodules as benign, malignant, or indeterminate on the basis of their number, unilateral versus bilateral distribution, size, margins (indistinct vs distinct), calcification, growth, and associated adenopathy. These classifications were compared with nodule histologic type, and interreviewer agreement was assessed.

RESULTS

The median patient age was 14.8 years (mean, 13.7 years; range, 5-21 years). Twenty-four of the 41 patients (58%) had at least one biopsy-proved malignant nodule. Four (10%) patients had both benign and malignant nodules; 17 (42%) had only benign nodules. Reviewer 1 classified 65% (39 of 60) of nodules correctly; reviewer 2, 57% (37 of 65); and reviewer 3, 67% (43 of 64). Interreviewer agreement was slight to moderate (kappa </= 0.43, P </= .03). In contrast to findings in adults, sharply defined nodules in younger individuals were more likely to be malignant (P = .03) and nodule size was not associated with malignancy (P >/= .32).

CONCLUSION

The frequency of benign nodules and the inconsistency of predictions based on CT features suggest the need for better predictors of pulmonary nodules being malignant or benign, so as to reduce unnecessary thoracotomy in pediatric patients with solid malignancy. .

Intrathoracoscopic localization techniques

BACKGROUND

Several techniques for localizing pulmonary nodules have been described, but the advantages and disadvantages of each method remain unclear. We reviewed ultrasound, endofinger, finger palpation and wait and watch, radioguided, vital dye, fluoroscopic, agar marking, and needle wire methods for localizing pulmonary nodules.

METHODS

Original, peer-reviewed, and full-length articles in English were searched with PubMed and ISI Web of Sciences. Case reports and case series with less than 10 patients were excluded.

RESULTS

All localization techniques showed good reliability, but some carry a high rate of major or minor complications and drawbacks.

CONCLUSION

No ideal localization technique is available; thus, the choice still depends on surgeon's preference and local availability of both specialists and instruments.

Combining Bronchoscopy and Positron Emission Tomography for the Diagnosis of the Small Pulmonary Nodule ≤ 3 cm

AIM

To assess the role of bronchoscopy and positron emission tomography (PET) scanning in an integrated approach for the diagnosis of noncalcified, small, chest radiologic lesions (< or = 3 cm).

METHODS

Seventy-four consecutive patients (29 men; mean age, 64 years) with a pulmonary nodule < or = 3 cm undergoing both combined PET and bronchoscopy were included. When bronchoscopy and PET findings were negative, a multidisciplinary decision was taken to perform further invasive diagnostics or follow-up.

RESULTS

Malignancy was diagnosed in 51 patients (69%), and a positive benign diagnosis was made in 9 patients (12%). Six patients (8%) had endobronchial lesions. Bronchoscopy was diagnostic in 53% patients (cancer, n = 35; benign, n = 4). PET findings were positive in 19 of 35 patients with a nondiagnostic bronchoscopy. In these 19 patients, malignant diagnosis was made in 14 patients (CT-fine needle aspiration [FNA], n = 3; thoracoscopic biopsy, n = 3; resection, n = 7; FNA of PET-positive supraclaviclar lymph node, n = 1), and a benign diagnosis was made in 5 patients (CT-FNA, n = 1; thoracoscopic biopsy, n = 1; resection, n = 1; follow-up, n = 2). In 16 patients with nondiagnostic bronchoscopy and negative PET findings, 5 patients had a tissue diagnosis (cancer, n = 2 [< 1 cm]; benign, n = 3) and 11 patients were followed up. Sixty-seven patients had a lesion 11 mm to 3 cm; among these, all 12 patients who were bronchoscopy negative and PET negative had benign lesions. In 24 patients without mediastinal adenopathy (solitary pulmonary nodule), bronchoscopy was diagnostic in 12 patients (cancer, n = 11; bronchiolitis obliterans organizing pneumonia, n = 1). In the remaining 12 patients, PET findings were positive in 6 patients (cancer, n = 3; resection, n = 2; CT-FNA, n = 1) and negative in 6 patients (benign, n = 2, both on resection; follow-up, n = 4).

CONCLUSION

Combining bronchoscopy and PET scanning has an useful role in the diagnosis of noncalcified chest radiologic lesions < or = 3 cm in size. Bronchoscopy has a diagnostic yield of > 50% and also allows the diagnosis of endobronchial lesions. If bronchoscopy is nondiagnostic, a PET scan should be performed.

Fluorodeoxyglucose-PET in characterizing solitary pulmonary nodules, assessing pleural diseases, and the initial staging, restaging, therapy planning, and monitoring response of lung cancer

Fluorodeoxyglucose-PET imaging has secured an important role in the assessment and management of a multitude of pulmonary disorders, including solitary pulmonary nodules, lung cancer, and pleural diseases. While conventional imaging modalities such as chest radiography and CT are considered essential in these settings, FDG-PET can provide new information and complement structural imaging techniques in the evaluation of such disorders. In this review, the authors present a growing body of evidence that demonstrates and supports the utility of FDG-PET in the differentiation of benign and malignant pulmonary nodules, the assessment of lung cancer in various stages of disease, and the characterization of pleural diseases. In addition, new developments--such as prospects for potential utility of novel radiotracers and delayed imaging--that can further refine the role of FDG scans in the work-up of lung nodules and cancer and forecast the future place of PET in these common modalities are discussed.