Endobronchial ultrasound for peripheral lesions: a review

Predictive value of the resistance of the probe to pass through the lesion in the diagnosis of peripheral pulmonary lesions using radial probe endobronchial ultrasound with a guide sheath

Background

Transbronchial lung biopsy guided by radial probe endobronchial ultrasonography with a guide sheath (EBUS-GS-TBLB) is becoming a significant approach for diagnosing peripheral pulmonary lesions (PPLs). We aimed to explore the clinical value of the resistance of the probe to pass through the lesion in the diagnosis of PPLs when performing EBUS-GS-TBLB, and to determine the optimum number of EBUS-GS-TBLB.

Methods

We performed a prospective, single-center study of 126 consecutive patients who underwent EBUS-GS-TBLB for solid and positive-bronchus-sign PPLs where the probe was located within the lesion from September 2019 to May 2022. The classification of probe resistance for each lesion was carried out by two bronchoscopists independently, and the final result depended on the bronchoscopist responsible for the procedures. The primary endpoint was the diagnostic yield according with the resistance pattern. The secondary endpoints were the optimum number of EBUS-GS-TBLB and factors affecting diagnostic yield. Procedural complications were also recorded.

Results

The total diagnostic yield of EBUS-GS-TBLB was 77.8%, including 83.8% malignant and 67.4% benign diseases (P=0.033). Probe resistance type II displayed the highest diagnostic yield (87.5%), followed by type III (81.0%) and type I (61.1%). A significant difference between the diagnostic yield of malignant and benign diseases was detected in type II (P = 0.008), whereas others did not. Although most of the malignant PPLs with a definitive diagnosis using EBUS-GS-TBLB in type II or type III could be diagnosed in the first biopsy, the fourth biopsy contributed the most sufficient biopsy samples. In contrast, considerably limited tissue specimens could be obtained for each biopsy in type I. The inter-observer agreement of the two blinded bronchoscopists for the classification of probe resistance was excellent (κ = 0.84).

Conclusion

The probe resistance is a useful predictive factor for successful EBUS-GS-TBLB diagnosis of solid and positive-bronchus-sign PPLs where the probe was located within the lesion. Four serial biopsies are appropriate for both probe resistance type II and type III, and additional diagnostic procedures are needed for type I.

[Chinese Experts Consensus on Artificial Intelligence Assisted Management for Pulmonary Nodule (2022 Version)]

Low-dose computed tomography (CT) for lung cancer screening has been proven to reduce lung cancer deaths in the screening group compared with the control group. The increasing number of pulmonary nodules being detected by CT scans significantly increase the workload of the radiologists for scan interpretation. Artificial intelligence (AI) has the potential to increase the efficiency of pulmonary nodule discrimination and has been tested in preliminary studies for nodule management. As more and more artificial AI products are commercialized, the consensus statement has been organized in a collaborative effort by Thoracic Surgery Committee, Department of Simulated Medicine, Wu Jieping Medical Foundation to aid clinicians in the application of AI-assisted management for pulmonary nodules.
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Accurate diagnosis of pulmonary nodules using a noninvasive DNA methylation test

BACKGROUNDCurrent clinical management of patients with pulmonary nodules involves either repeated low-dose CT (LDCT)/CT scans or invasive procedures, yet causes significant patient misclassification. An accurate noninvasive test is needed to identify malignant nodules and reduce unnecessary invasive tests.METHODWe developed a diagnostic model based on targeted DNA methylation sequencing of 389 pulmonary nodule patients' plasma samples and then validation in 140 plasma samples independently. We tested the model in different stages and subtypes of pulmonary nodules.RESULTSA 100-feature model was developed and validated for pulmonary nodule diagnosis; the model achieved a receiver operating characteristic curve-AUC (ROC-AUC) of 0.843 on 140 independent validation samples, with an accuracy of 0.800. The performance was well maintained in (a) a 6 to 20 mm size subgroup (n = 100), with a sensitivity of 1.000 and adjusted negative predictive value (NPV) of 1.000 at 10% prevalence; (b) stage I malignancy (n = 90), with a sensitivity of 0.971; (c) different nodule types: solid nodules (n = 78) with a sensitivity of 1.000 and adjusted NPV of 1.000, part-solid nodules (n = 75) with a sensitivity of 0.947 and adjusted NPV of 0.983, and ground-glass nodules (n = 67) with a sensitivity of 0.964 and adjusted NPV of 0.989 at 10% prevalence. This methylation test, called PulmoSeek, outperformed PET-CT and 2 clinical prediction models (Mayo Clinic and Veterans Affairs) in discriminating malignant pulmonary nodules from benign ones.CONCLUSIONThis study suggests that the blood-based DNA methylation model may provide a better test for classifying pulmonary nodules, which could help facilitate the accurate diagnosis of early stage lung cancer from pulmonary nodule patients and guide clinical decisions.FUNDINGThe National Key Research and Development Program of China; Science and Technology Planning Project of Guangdong Province; The National Natural Science Foundation of China National.

Diagnostic value of radial endobronchial ultrasonographic features in predominant solid peripheral pulmonary lesions

Background

Transbronchial lung biopsy (TBLB) of peripheral pulmonary lesions (PPLs) is usually performed for a definite diagnosis. Radial probe endobronchial ultrasonography is often acknowledged as a good guidance method for TBLB as it can help physicians confirm the lesions’ position. It is also a non-invasive imaging diagnostic method. This clinical study was designed to evaluate the ability of radial endobronchial ultrasonography (R-EBUS) to differentiate benign from malignant predominant solid PPLs based on imaging features.

Methods

Patients with predominant solid PPLs were enrolled in this study retrospectively. TBLB was performed using R-EBUS with or without other guidance techniques. One typical sonographic image and one video of each lesion were recorded for analysis. Six radial probe endobronchial ultrasonographic image features (size, shape, echogenicity, margin, blood vessel, and linear-discrete air bronchogram) were studied by ultrasonography specialists and physicians who were blinded to the final diagnosis. The sum score model of the combined predictive factors indicated the best diagnostic accuracies for predicting malignant PPLs. The model group results were used to establish the diagnostic standard for a verification group.

Results

A total of 303 patients were enrolled in the model group from July 2018 to July 2019 at the Shanghai Chest Hospital (214 with malignant and 89 with benign lesions). The mean lesion long axis on computed tomographic images was 34.39±13.79 mm. There were significant statistical differences between benign and malignant lesions in the long axis, short axis, shape, margin, blood vessel, and linear-discrete air bronchogram assessed by radial endobronchial ultrasound. Long axis, lobulation, distinct but not sharp margin, absence of blood vessel, and absence of linear-discrete air bronchogram were good predictive factors of malignant lesions. A sum score model value of 79.54% of these combined factors indicated the best diagnostic accuracy for predicting malignant lesions. Eighty-seven patients were enrolled in the verification group from August to October 2019. The sum score model showed a diagnostic accuracy of 82.76%.

Conclusions

Radial endobronchial ultrasonographic features can differentiate malignant from benign lesions and thus have potential diagnosis value in predominant solid PPLs.

Convex probe endobronchial ultrasound: historical, contemporary, and cutting-edge applications

The use of convex-probe endobronchial ultrasound (CP-EBUS) has revolutionized bronchoscopy. It has provided the option of a relatively safe, minimally invasive approach for the assessment of various intrathoracic diseases. In current practice, its most dramatic impact has been on the diagnosing and staging of lung cancer. It has served as an invaluable tool that has replaced mediastinoscopy in a variety of clinical scenarios. Many pulmonologists and thoracic surgeons consider CP-EBUS the most significant milestone in bronchoscopy after the development of the flexible bronchoscope itself. In this review, we summarize the historical aspects, current indications, technical approach, and future direction of CP-EBUS.

Radial endobronchial ultrasound-guided transbronchial biopsy for peripheral pulmonary malignancy: biopsy- or brushing-first?

Background

Radial endobronchial ultrasound (R-EBUS)-guided transbronchial biopsy (TBB) is a common diagnostic modality for peripheral pulmonary lesions; however, there is uncertainty about the optimal sequence of TBB and bronchial brushing during the procedure. Thus, we aimed to investigate whether a biopsy-first or brushing-first strategy confers a better diagnostic yield and safety signal for R-EBUS-guided procedures for peripheral pulmonary malignancy.

Methods

From January 2017 to June 2018, consecutive patients referred for R-EBUS-guided TBB and bronchial brushing of peripheral pulmonary lesions and with a final malignant diagnosis were included. Patients were placed in a biopsy-first (biopsy followed by brushing) or a brushing-first (brushing followed by biopsy) group. The outcomes of interest were the diagnostic yield and complication profile of the procedures. Multivariate logistic regression and subgroup analysis were used to assess the impact of the procedure strategy.

Results

A total of 438 patients were included and the diagnostic yield of R-EBUS-guided TBB plus brushing for peripheral pulmonary malignancy was 73%. The diagnostic yield was associated with the solid lesion appearance (odds ratio [OR] 2.01; 95% confidence interval [CI] 1.08–3.75) and R-EBUS probe position within the lesion (OR 1.92; 95% CI 1.08–3.42), and the yield rates were comparable between the biopsy-first and brushing-first strategies. Moreover, the safety signal did not differ between the two groups.

Conclusions

The two procedure strategies were indistinguishable in terms of diagnostic efficacy and adverse events for patients with peripheral pulmonary malignancy. Current evidence indicates that in patients with peripheral pulmonary lesions suspected of being malignant, either biopsy-first or brushing-first is a viable and acceptable diagnostic strategy during R-EBUS-guided procedures.

The value of repeat radial-probe endobronchial ultrasound-guided transbronchial biopsy after initial non-diagnostic results in patients with peripheral pulmonary lesions

Background

Radial-probe endobronchial ultrasound (rEBUS)-guided transbronchial biopsy (TBB) is invaluable in the diagnosis of peripheral pulmonary lesions (PPLs); however, in certain instances, the procedure has to be repeated because of initial non-diagnostic procedure(s). Little if any literature has been published on this issue. Therefore, the aim of this study was to investigate the utility of repeat rEBUS-guided TBB in achieving a definitive diagnosis of PPLs.

Methods

All patients who underwent rEBUS-guided TBB of PPLs at National Taiwan University Hospital between 2011 and 2015 and had a repeat procedure after non-diagnostic initial procedures were identified as the study subjects. The primary outcome of interest was the diagnostic yield of repeat rEBUS-guided TBB for PPLs. Also, we sought to discover features associated with the yield of repeat procedures.

Results

Forty-three (11%) out of 384 patients with initial non-diagnostic TBB were included for analysis. A diagnosis of PPLs was able to be confirmed with repeat TBB in 23(53%) patients. The pathology of the first TBB was significantly associated with the yield of repeat procedures (P = 0.011). Further, patients with normal lung tissue in initial pathology rarely (2/12, 17%) had a definite diagnosis on repeat TBB. Yet, patients with pathology showing atypical cells and other non-specific findings were more likely (21/31, 68%) to obtain a confirmed diagnosis. The diagnostic yield of repeat procedures was not affected by the size, location or CT appearance of the lesions, or position of the rEBUS probe. No death or other serious adverse events occurred with the repeat rEBUS-guided procedures.

Conclusions

If clinically indicated, it is reasonable to repeat rEBUS-guided TBB after an initial non-diagnostic procedure as the diagnostic yield will be at least 50% and the side effect profile is favorable.

Nodular pulmonary amyloidosis: a complex disease with malignancy association

Pulmonary amyloidosis is a rare disease that incorporates deposition of amyloid microfibril material in the lung parenchyma. The condition generally presents as an indolent subacute-to-chronic pulmonary disease and requires tissue biopsy to establish the diagnosis. Nodular pulmonary amyloidosis, a subtype of pulmonary amyloidosis, is characterised by special radiographic and pathological features. While the disease can be associated with inflammatory conditions; its association with mucosal-associated lymphoid tissue (MALT lymphoma) is unusual and carries management challenges. Herein, we illustrate a case study of nodular pulmonary amyloidosis associated with underlying MALT lymphoma in a patient with known systemic lupus erythematosus. The aim of this article is to share the management experience of this complex condition with the medical community and to conduct an up-to-date literature review on nodular pulmonary amyloidosis.

Endobronchial ultrasonography using a guide sheath technique for diagnosis of peripheral pulmonary lesions

Endobronchial ultrasonography using a guide sheath (EBUS-GS) is a novel method used for collecting peripheral pulmonary lesion (PPL) samples. EBUS-GS is performed by introducing a guide sheath-covered miniprobe into the target bronchus and then withdrawing the miniprobe after lesion detection, leaving the guide sheath in situ as a working channel for obtaining lesion samples. EBUS-GS can improve PPL diagnosis rates and be used for obtaining specimens for molecular analysis. In this review, we discuss the clinical applications of EBUS-GS, the factors that affect its diagnostic sensitivity, and potential complications. We also compare EBUS-GS with other available diagnostic techniques and discuss the strengths and limitations of this method.

Endoscopic ultrasound in the diagnosis of mediastinal diseases

EUS is a useful tool for diagnosis of mediastinal diseases. EUS-FNA plays an important role in staging of lung cancer and in tissue acquisition in patients with mediastinal masses. In this review, the following issues will be addressed: EUS-FNA and EBUS-TBNA, metastatic mediastinal lymph nodes diagnosed by EUS, EUS in assessment of mediastinal lymph node status for staging of lung cancer, mediastinal lymphoma diagnosed by EUS, sarcoidosis and tuberculosis diagnosed by EUS.

The Role of Airway and Endobronchial Ultrasound in Perioperative Medicine

Recent years have witnessed an increased use of ultrasound in evaluation of the airway and the lower parts of the respiratory system. Ultrasound examination is fast and reliable and can be performed at the bedside and does not carry the risk of exposure to ionizing radiation. Apart from use in diagnostics it may also provide safe guidance for invasive and semi-invasive procedures. Ultrasound examination of the oral cavity structures, epiglottis, vocal cords, and subglottic space may help in the prediction of difficult intubation. Preoperative ultrasound may diagnose vocal cord palsy or deviation or stenosis of the trachea. Ultrasonography can also be used for confirmation of endotracheal tube, double-lumen tube, or laryngeal mask placement. This can be achieved by direct examination of the tube inside the trachea or by indirect methods evaluating lung movements. Postoperative airway ultrasound may reveal laryngeal pathology or subglottic oedema. Conventional ultrasound is a reliable real-time navigational tool for emergency cricothyrotomy or percutaneous dilational tracheostomy. Endobronchial ultrasound is a combination of bronchoscopy and ultrasonography and is used for preoperative examination of lung cancer and solitary pulmonary nodules. The method is also useful for real-time navigated biopsies of such pathological structures.

A rare case of mediastinal metastasis of ovarian carcinoma diagnosed by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA)

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has become a minimally invasive tool with excellent diagnostic accuracy and low risk of complications in the diagnosis of thoracic diseases, including lung cancers and primary mediastinal lesions. Occasionally, EBUS-TBNA may be useful in identifying thoracic metastasis from distant tumors. Here we report an interesting and rare case of mediastinal metastasis of ovarian carcinoma diagnosed by EBUS-TBNA.

Convex probe endobronchial ultrasound: applications beyond conventional indications

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is maturing and gaining acceptance by more and more clinicians for lymph node staging of lung cancer and diagnosis of mediastinal and hilar masses or lymph node enlargement by convex probe endobronchial ultrasound (CP-EBUS). The application of CP-EBUS, however, is not limited to conventional indications. Diagnostically, elastography is a new technology for the differentiation of benign and malignant lymph nodes before aspiration. CP-EBUS can also be used for pulmonary vascular diseases, such as pulmonary embolism (PE) and non-thrombotic endovascular lesions (NELs). Therapeutically, CP-EBUS can be used for cyst drainage and drug injections. CP-EBUS is not limited to observation and aspiration of mediastinal masses and lymph nodes, but is also suitable for exploration of other tissues external to the central airway, which necessitates unprecedented skills for the bronchoscopist.

Preliminary study of CT in combination with MRI perfusion imaging to assess hemodynamic changes during angiogenesis in a rabbit model of lung cancer

Background

This study used CT (computed tomography) and magnetic resonance imaging (MRI) to identify correlations between perfusion parameters for squamous cell lung carcinoma and tumor angiogenesis in a rabbit model of VX2 lung cancer.

Methods

VX2 tumors were implanted in the lungs of 35 New Zealand White rabbits. CT and MRI perfusion scanning were performed on days 14, 17, 21, 25, and 28 after tumor implantation. CT perfusion parameters were perfusion, peak enhanced increment, transit time peak, and blood volume, and MRI perfusion parameters were wash in rate, wash out rate, maximum enhancement rate, and transit time peak. CT and MRI perfusion parameters were obtained at the tumor rim, in the tumor tissue, and in the muscle tissue surrounding the tumor.

Results

On CT perfusion imaging, t values for perfusion, peak enhanced increment, and blood volume (tumor rim versus muscle) were 16.31, 11.79, and 5.21, respectively (P < 0.01); t values for perfusion, peak enhanced increment, and blood volume (tumor versus muscle) were 9.87, 4.09, and 5.35, respectively (P < 0.01); and t values for transit time peak were 1.52 (tumor rim versus muscle) and 1.29 (tumor versus muscle), respectively (P > 0.05). On MRI perfusion imaging, t values for wash in rate, wash out rate, and maximum enhancement rate (tumor rim versus muscle) were 18.14, 8.79, and 6.02, respectively (P < 0.01); t values for muscle wash in rate, wash out rate, and maximum enhancement rate (tumor versus muscle) were 9.45, 8.23, and 4.21, respectively (P < 0.01); and t values for transit time peak were 1.21 (tumor rim versus muscle) and 1.05 (tumor versus muscle), respectively (P > 0.05).

Conclusion

A combination of CT and MRI perfusion imaging demonstrated hemodynamic changes in a rabbit model of VX2 lung cancer, and provides a theoretical foundation for treatment of human squamous cell lung carcinoma.