Determining malignancy in CT guided fine needle aspirate biopsy of subsolid lung nodules: Is core biopsy necessary?

Lung Needle Biopsy and Lung Ablation: Indications, Patient Management, and Postprocedure Imaging Findings

The clinical role and use of percutaneous transthoracic needle biopsy (TTNB) and ablation of lung tumors are evolving. Here we discuss important considerations for referring providers, including current and emerging indications supported by guidelines, critical aspects of pre and postprocedure patient management, and expected postprocedure imaging findings.

Subsolid Nodules: Significance and Current Understanding

Subsolid nodules are heterogeneously appearing and behaving entities, commonly encountered incidentally and in high-risk populations. Accurate characterization of subsolid nodules, and application of evolving surveillance guidelines, facilitates evidence-based and multidisciplinary patient-centered management.

Accuracy of solid portion size measured on multiplanar volume rendering images for assessing invasiveness in lung adenocarcinoma manifesting as subsolid nodules

Background

The solid component of subsolid nodules (SSNs) is closely associated with the invasiveness of lung adenocarcinoma, and its accurate assessment is crucial for selecting treatment method. Therefore, this study aimed to evaluate the accuracy of solid component size within SSNs measured on multiplanar volume rendering (MPVR) and compare it with the dimensions of invasive components on pathology.

Methods

A pilot study was conducted using a chest phantom to determine the optimal MPVR threshold for the solid component within SSN, and then clinical validation was carried out by retrospective inclusion of patients with pathologically confirmed solitary SSN from October 2020 to October 2021. The radiological tumor size on MPVR and solid component size on MPVR (RSSm) and on lung window (RSSl) were measured. The size of the tumor and invasion were measured on the pathological section, and the invasion, fibrosis, and inflammation within SSNs were also recorded. The measurement difference between computed tomography (CT) and pathology, inter-observer and inter-measurement agreement were analyzed. Receiver operating characteristic (ROC) analysis and Bland-Altman plot were performed to evaluate the diagnostic efficiency of MPVR.

Results

A total of 142 patients (mean age, 54±11 years, 39 men) were retrospectively enrolled in the clinical study, with 26 adenocarcinomas in situ, 92 minimally invasive adenocarcinomas (MIAs), and 24 invasive adenocarcinomas (IAs). The RSSl was significantly smaller than pathological invasion size with fair inter-measurement agreement [intraclass correlation coefficient (ICC) =0.562, P<0.001] and moderate interobserver agreement (ICC =0.761, P<0.001). The RSSm was significantly larger than pathological invasion size with the excellent inter-measurement agreement (ICC =0.829, P<0.001) and excellent (ICC =0.952, P<0.001) interobserver agreement. ROC analysis showed that the cutoff value of RSSm for differentiating adenocarcinoma in situ from MIA and MIA from IA was 1.85 and 6.45 mm (sensitivity: 93.8% and 95.5%, specificity: 85.7% and 88.2%, 95% confidence internal: 0.914-0.993 and 0.900-0.983), respectively. The positive predictive value-and negative predictive value of MPVR in predicting invasiveness were 92.8% and 100%, respectively.

Conclusions

Using MPVR to predict the invasive degree of SSN had high accuracy and good inter-observer agreement, which is superior to lung window measurements and helpful for clinical decision-making.

An Effective Malignancy Prediction Model for Incidentally Detected Pulmonary Subsolid Nodules Based on Current and Prior CT Scans

INTRODUCTION

It is challenging to diagnose and manage incidentally detected pulmonary subsolid nodules due to their indolent nature and heterogeneity. The objective of this study is to construct a decision tree-based model to predict malignancy of a subsolid nodule based on radiomics features and evolution over time.

MATERIALS AND METHODS

We derived a training set (2947 subsolid nodules), a test set (280 subsolid nodules) from a cohort of outpatient CT scans, and a second test set (5171 subsolid nodules) from the National Lung Cancer Screening Trial (NLST). A Computer-Aided Diagnosis system (CADs) automatically extracted 28 preselected radiomics features, and we calculated the feature change rates as the change of the quantitative measure per time unit between the prior and current CT scans. We built classification models based on XGBoost and employed 5-fold cross validation to optimize the parameters.

RESULTS

The model that combined radiomics features with their change rates performed the best. The Areas Under Curve (AUCs) on the outpatient test set and on the NLST test set were 0.977 (95% CI, 0.958-0.996) and 0.955 (95% CI, 0.930-0.980), respectively. The model performed consistently well on subgroups stratified by nodule diameters, solid components, and CT scan intervals.

CONCLUSION

This decision tree-based model trained with the outpatient dataset gives promising predictive performance on the malignancy of pulmonary subsolid nodules. Additionally, it can assist clinicians to deliver more accurate diagnoses and formulate more in-depth follow-up strategies.

Surgical Resection of Benign Nodules in Lung Cancer Screening: Incidence and Features

Introduction

Interventions and surgical procedures are common for nonmalignant lung lesions detected on lung cancer screening (LCS). Inadvertent surgical resection of benign nodules with a clinical suspicion of lung cancer can occur, can be associated with complications, and adds to the cost of screening. The objective of this study is to assess the characteristics of surgically resected benign nodules detected on LCS computed tomography which were presumed to be lung cancers.

Methods

This retrospective study included 4798 patients who underwent LCS between June 2014 and January 2021. The benign lung nodules, surgically resected with a presumed cancer diagnosis, were identified from the LCS registry. Patient demographics, imaging characteristics, and pathologic diagnoses of benign nodules were analyzed.

Results

Of the 4798 patients who underwent LCS, 148 (3.1%) underwent surgical resection of a lung nodule, and of those who had a resection, 19 of 148 (12.8%) had a benign diagnosis (median age = 64 y, range: 56-77 y; F = 12 of 19, 63.2%; M = seven of 19, 36.8%). The median nodule size was 10 mm (range: 6-31 mm). Most nodules were solid (15 of 19, 78.9%), located in the upper lobes (11 of 19; 57.9%), and were peripheral (17 of 19, 89.5%). Most nodules (13 of 17; 76.5%) had interval growth, and four of 17 (23.5%) had increased fluorodeoxyglucose uptake. Of the 19 patients, 17 (89.5%) underwent sublobar resection (16 wedge resection and one segmentectomy), whereas two central nodules (10.5%) had lobectomies. Pathologies identified included focal areas of fibrosis or scarring (n = 8), necrotizing granulomatous inflammation (n = 3), other nonspecific inflammatory focus (n = 3), benign tumors (n = 3), reactive lymphoid hyperplasia (n = 1), and organizing pneumonia (n = 1).

Conclusions

Surgical resections of benign nodules that were presumed malignant are infrequent and may be unavoidable given overlapping imaging features of benign and malignant nodules. Knowledge of benign pathologies that can mimic malignancy may help reduce the incidence of unnecessary surgeries.

Managing Persistent Subsolid Nodules in Lung Cancer: Education, Decision Making, and Impact of Interval Growth Patterns

With the popularization of lung cancer screening, many persistent subsolid nodules (SSNs) have been identified clinically, especially in Asian non-smokers. However, many studies have found that SSNs exhibit heterogeneous growth trends during long-term follow ups. This article adopted a narrative approach to extensively review the available literature on the topic to explore the definitions, rationale, and clinical application of different interval growths of subsolid pulmonary nodule management and follow-up strategies. The development of SSN growth thresholds with different growth patterns could support clinical decision making with follow-up guidelines to reduce over- and delayed diagnoses. In conclusion, using different SSN growth thresholds could optimize the follow-up management and clinical decision making of SSNs in lung cancer screening programs. This could further reduce the lung cancer mortality rate and potential harm from overdiagnosis and over management.

Diagnostic performance and safety of percutaneous fine-needle aspiration immediately before microwave ablation for pulmonary ground-glass nodules

Background

This study sought to evaluate the safety and diagnostic performance of computed tomography (CT)-guided fine-needle aspiration (FNA) immediately before microwave ablation (MWA) for pulmonary ground-glass nodules (GGNs).

Methods

This retrospective study analyzed the synchronous CT-guided biopsy and MWA data of 92 GGNs (male to female ratio 37:55; age 60.4±12.5 years; size 1.4±0.6 cm). FNA was performed in all patients, and sequential core-needle biopsy (CNB) was performed in 62 patients. The positive diagnosis rate was determined. The diagnostic yield was compared on the basis of the biopsy methods (FNA, CNB, or both), the nodule diameter (<1.5 and ≥1.5 cm), and the lesion component (pure GGN or part-solid GGN). The procedure-related complications were recorded.

Results

The technical success rate was 100%. The positive rates of FNA and CNB were 70.7% and 72.6% respectively, but did not differ significantly (P=0.8). Sequential FNA and CNB showed better diagnostic performance (88.7%) than did either alone (P=0.008 and P=0.023, respectively). The diagnostic yield of CNB for pure GGNs was significantly lower than that for part-solid GGNs (P=0.016). The diagnostic yield was lower for smaller nodules (78.3% vs. 87.5%; P=0.28), but the differences were not significant. Grade 1 pulmonary hemorrhages were observed in 10 (10.9%) sessions after FNA, including 8 cases of hemorrhage along the needle track and 2 cases of perilesional hemorrhage, but these hemorrhages did not hamper the accuracy of the antenna placement.

Conclusions

FNA immediately before MWA is a reliable technique for the diagnosis of GGNs that does not alter the accuracy of the antenna placement. Sequential FNA and CNB improves the diagnostic ability of GGNs compared to either method used alone.

Diagnostic accuracy and adequacy of peripheral pulmonary nodules samples obtained by transthoracic needle aspiration

OBJECTIVE

To examine the adequacy of samples and accuracy of transthoracic needle aspiration (TTNA) in patients with peripheral pulmonary nodule (PPN) diagnosis.

METHODS

This retrospective study included 248 patients who underwent TTNA of PPN and subsequent diagnostic and therapeutic surgical procedures during a 5-year period at the Institute for Pulmonary Diseases of Vojvodina. The following were analysed: adequacy of cytological samples for diagnosis and molecular testing, tumour localisation and dimensions, and cytological and histopathological characteristics.

RESULTS

The adequacy of the cytological samples was 93.15%. The proportion of adequate-diagnostic samples was higher in patients in whom the largest diameter of the lesion was >4 cm, and this difference showed statistical significance. Tumour localisation was not statistically significant for the adequacy of samples for cytological analysis. Cytological samples of lung adenocarcinoma had high projected adequacy for EGFR analyses of 91.55%, not dependent on the size and location of the lesion. The most commonly diagnosed lung tumour was adenocarcinoma (45.51%). Patients with a cytological diagnosis of non-small cell carcinoma not otherwise specified, after histopathological analyses, had adenocarcinoma in most cases (53.85%). The overall accuracy of TTNA in the diagnosis of PPN was 71%. The method's accuracy was 75.24% for malignant tumours, while it was 28.57% for benign tumours. The accuracy of cytological analysis for the histological type of tumour was 84.18%.

CONCLUSION

Transthoracic needle aspiration with cytological analysis is an effective and highly sensitive method in determining the aetiology of PPN.

The diagnostic value of CT-guided percutaneous puncture biopsy of pulmonary ground-glass nodules: a meta-analysis

Background

More and more pulmonary ground-glass nodules (GGNs) are screened with the extensive usage of low-dose computed tomography (CT). The need of CT-guided percutaneous puncture biopsy of GGN remains controversial.

Purpose

To explore the diagnostic accuracy of CT-guided percutaneous puncture biopsy of GGNs.

Material and Methods

We searched PubMed, EMBASE, the Cochrane Library, and CNKI. Included studies reported the puncture biopsy results of pulmonary GGNs, including the number of true positive (TP), false positive (FP), true negative (TN), and false negative (FN) cases. After evaluating the studies, statistical analysis, and quality assessment, the pooled diagnostic sensitivity (SEN), specificity (SPE), and diagnostic odds ratio (DOR) were calculated. The summary receiver operating characteristic (SROC) curve was constructed and the area under the curve (AUC) was calculated. Subgroup analysis was performed according to whether spiral CT or fluoroscopy-guided CT was used in the study.

Results

This meta-analysis included 14 studies with a total of 759 patients (702 samples). The pooled SEN, SPE, and DOR of CT-guided puncture biopsy of pulmonary GGNs were 0.91 (95% confidence interval [CI] = 0.89–0.94), 0.99 (95% CI = 0.95–1.00), and 138.72 (95% CI = 57.98–331.89), respectively. The AUC was 0.97.

Conclusion

Our results indicated that CT-guided puncture biopsy of GGNs has high SEN, SPE, and DOR, which proved that CT-guided puncture biopsy was a good way to determine the pathological nature of GGN.

Comparison of CT-Guided Core Needle Biopsy in Pulmonary Ground-Glass and Solid Nodules Based on Propensity Score Matching Analysis

Purpose: To compare the diagnostic accuracy and safety of computed tomography (CT)-guided core needle biopsy (CNB) between pulmonary ground-glass and solid nodules using propensity score matching (PSM) method and determine the relevant risk factors. Methods: This was a single-center retrospective cohort study using data from 665 patients who underwent CT-guided CNB of pulmonary nodules in our hospital between May 2019 and May 2021, including 39 ground-glass nodules (GGNs) and 626 solid nodules. We used a 1:4 PSM analysis to compared the diagnostic yields and complications rates of CT-guided CNB between 2 groups. Results: After PSM, 170 cases involved in the comparison (34 GGNs vs 136 solid nodules) were randomly matched (1:4) by patient demographics, clinical history, lesion characteristics, and procedure-related factors. There was no statistically significant difference in the diagnostic yields and complications rates between 2 groups. Significant pneumothorax incidence increase was noted at small lesion size, deep lesion location, and traversing interlobar fissure (P < .05). Post-biopsy hemorrhage was a protective factor for pneumothorax (P < .05). The size/proportion of consolidation of GGN did not influence the diagnostic accuracy and complication incidence (P > .05). Conclusions: The accuracy and safety of CT-guided CNB were comparable for ground-glass and solid nodules and the size/proportion of consolidation of GGN may be not a relevant risk factor. The biopsy should avoid traversing interlobar fissure as far as possible. Smaller lesion size and deeper lesion location may lead to higher pneumothorax rate and post-biopsy hemorrhage may be a protective factor for pneumothorax.

Solitary multicystic lesion lung cancer: two case reports and review of the literature

Background

Lung cancer associated with cystic airspaces, especially solitary multicystic lesion lung cancer, is a rare disease (a rare imaging performance of non-small cell lung cancer). It is difficult to diagnose owing to the lack of a clear definition; therefore, diagnosis of these neoplastic lesions remains challenging.

Case presentation

We outlined two cases of elderly Chinese men who were admitted to the hospital with a solitary multicystic lesion of the lung and subsequent surgical resection, confirming a diagnosis of adenocarcinoma.

Conclusions

For solitary pulmonary cystic airspaces (especially solitary multicystic lung lesions), it is important to properly recognise their imaging features. Due to the possibility of malignancies, timely surgery is an effective treatment strategy for early diagnosis.

Diagnostic accuracy and complication rate of image-guided percutaneous transthoracic needle lung biopsy for subsolid pulmonary nodules: a systematic review and meta-analysis

OBJECTIVES

To determine the diagnostic accuracy and complication rate of percutaneous transthoracic needle biopsy (PTNB) for subsolid pulmonary nodules and sources of heterogeneity among reported results.

METHODS

We searched PubMed, EMBASE, and Cochrane libraries (until November 7, 2020) for studies measuring the diagnostic accuracy of PTNB for subsolid pulmonary nodules. Pooled sensitivity and specificity of PTNB were calculated using a bivariate random-effects model. Bivariate meta-regression analyses were performed to identify sources of heterogeneity. Pooled overall and major complication rates were calculated.

RESULTS

We included 744 biopsies from 685 patients (12 studies). The pooled sensitivity and specificity of PTNB for subsolid nodules were 90% (95% confidence interval [CI]: 85-94%) and 99% (95% CI: 92-100%), respectively. Mean age above 65 years was the only covariate significantly associated with higher sensitivity (93% vs  85%, p = 0.04). Core needle biopsy showed marginally higher sensitivity than fine-needle aspiration (93% vs  83%, p = 0.07). Pooled overall and major complication rate of PTNB were 43% (95% CI: 25-62%) and 0.1% (95% CI: 0-0.4%), respectively. Major complication rate was not different between fine-needle aspiration and core needle biopsy groups (p = 0.25).

CONCLUSION

PTNB had acceptable performance and a low major complication rate in diagnosing subsolid pulmonary nodules. The only significant source of heterogeneity in reported sensitivities was a mean age above 65 years.

ADVANCES IN KNOWLEDGE

This is the first meta-analysis attempting to systemically determine the cause of heterogeneity in the diagnostic accuracy and complication rate of PTNB for subsolid pulmonary nodules.

Percutaneous Transthoracic Lung Biopsy: Optimizing Yield and Mitigating Risk

ABSTRACT

Percutaneous computed tomography-guided transthoracic lung biopsy is an effective and minimally invasive procedure to achieve tissue diagnosis. Radiologists are key in appropriate referral for further workup, with percutaneous computed tomography-guided transthoracic lung biopsy performed by both thoracic and general interventionalists. Percutaneous computed tomography-guided transthoracic lung biopsy is increasingly performed for both diagnostic and research purposes, including molecular analysis. Multiple patient, lesion, and technique-related variables influence diagnostic accuracy and complication rates. A comprehensive understanding of these factors aids in procedure planning and may serve to maximize diagnostic yield while minimizing complications, even in the most challenging scenarios.

Clinicopathologic and Longitudinal Imaging Features of Lung Cancer Associated With Cystic Airspaces: A Systematic Review and Meta-Analysis

BACKGROUND. Lung cancer (LC) associated with cystic airspaces is an uncommon presentation that is underrecognized on imaging. Additionally, understanding of its underlying pathology and risk factors is limited, which can contribute to delays in diagnosis. OBJECTIVE. The purpose of this analysis was to systematically review, analyze, and synthesize the medical literature to determine the imaging features of LC associated with cystic airspaces. EVIDENCE ACQUISITION. In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included published research reporting the clinical, pathologic, and imaging features of LC associated with cystic airspaces. We then performed a pooled analysis of continuous and categoric data with respect to patient clinical characteristics, tumor pathologic features, underlying driver mutation, CT features, and evolution of these features over time. EVIDENCE SYNTHESIS. The analysis included eight original observational studies with a combined total of 341 patients with LC associated with cystic airspaces (weighted mean age, 61.8 years; range, 30-87 years; 135 women and 206 men). Most patients were current or previous smokers (127/192 [66.1%]). The most common histologic finding was adenocarcinoma (289/328 [88.1%]) followed by squamous cell carcinoma (30/328 [9.1%]). The most common driver mutations were EGFR (46/122 [37.7%]) and KRAS (21/122 [17.2%]). The cysts in LC associated with cystic airspaces commonly had nonuniform (104/114 [91.2%]) and thick (83/222 [37.4%]) walls, irregular margins (53/142 [37.3%]), and were unilocular (173/272 [63.6%]). Most cysts had a nodular component (210/328 [64.0%]). Over time, most cysts showed development or enlargement of the nodular component (61/89 [68.5%]), approximately half showed wall thickening (43/89 [48.3%]), and a minority evolved into completely solid lesions (11/89 [12.4%]). The size of the cystic component increased in 36 of 89 patients (40.4%), decreased in 28 (31.5%), and remained stable in 24 (27.0%). CONCLUSION. LC associated with cystic airspaces occurs most commonly as adeno-carcinoma and is seen in both smokers and nonsmokers. The cysts associated with LC show wall thickening and mural nodularity, which may evolve over time. LC associated with cystic airspaces can be indolent, and long-term surveillance with imaging should be considered if cysts are not resected. CLINICAL IMPACT. Familiarity with the imaging features and temporal evolution of LC associated with cystic airspaces can minimize delays in LC diagnosis. Future management guidelines should include protocols for follow-up and management of cystic lung lesions identified during diagnostic and LC screening CT.

Shades of Gray: Subsolid Nodule Considerations and Management

Subsolid nodules are common on chest CT imaging and may be either benign or malignant. Their varied features and broad differential diagnoses present management challenges. Although subsolid nodules often represent lung adenocarcinomas, other possibilities are common and influence management. Practice guidelines exist for subsolid nodule management for both incidentally and screening-detected nodules, incorporating patient and nodule characteristics. This review highlights the similarities and differences among these algorithms, with the intent of providing a resource for comparison and aid in choosing management options.