Imaging of Pleural Disease

Comparison of the diagnostic value of [68Ga]Ga-FAP-2286 PET/CT and [18F]-FDG PET/CT imaging in different types of pleural and peritoneal metastatic tumors

OBJECTIVE

To compare the diagnostic value of [68Ga]Ga-FAP-2286 PET/CT and [18F]-FDG PET/CT imaging in different types of pleural/peritoneal metastatic tumors.

METHODS

A retrospective analysis was conducted on patients who underwent both [18F]-FDG and [68Ga]Ga-FAP-2286 PET/CT in our department between January 2022 and November 2024. The maximum standardized uptake value (SUVmax), peak SUV (SUVpeak), and tumor-to-background ratio (TBR) of pleural/peritoneal metastatic lesions were measured, and the results obtained from the two imaging modalities were compared.

RESULTS

A total of 92 patients suspected of having pleural/peritoneal metastases were included in the study. The [68Ga]Ga-FAP-2286 PET/CT showed higher SUVmax, SUVpeak, TBR, and sensitivity compared to [18F]-FDG PET/CT (7.87 vs. 6.28; P = 0.002; 5.88 vs. 4.65; P < 0.001; 6.27 vs. 3.85; P < 0.001; 95.3% vs. 84.7%; P = 0.035), especially for peritoneal metastases (8.25 vs. 5.75; P < 0.001; 6.18 vs. 4.29; P < 0.001; 6.54 vs. 3.50; P < 0.001). Among various tumors, [68Ga]Ga-FAP-2286 PET/CT showed better detection results for hepatobiliary and pancreatic tumors (7.88 vs. 6.02, 5.88 vs. 4.33, 6.15 vs. 3.67), gastrointestinal tumors (8.27 vs. 5.69, 6.28 vs. 4.30, 7.03 vs. 3.50), and adenocarcinomas (8.30 vs. 5.80, 6.17 vs. 4.30, 6.60 vs. 3.55).

CONCLUSION

For pleural/peritoneal metastases, [68Ga]Ga-FAP-2286 PET/CT has a higher detection rate compared to [18F]-FDG PET/CT, providing better diagnostic efficacy, particularly for peritoneal metastases. Among various tumors, [68Ga]Ga-FAP-2286 PET/CT has higher diagnostic value in hepatobiliary and pancreatic tumors, gastrointestinal tumors, and adenocarcinomas.

Diagnosis of Pleural Mesothelioma: Is Everything Solved at the Present Time?

Ranked high in worldwide growing health issues, pleural diseases affect approximately one million people globally per year and are often correlated with a poor prognosis. Among these pleural diseases, malignant pleural mesothelioma (PM), a neoplastic disease mainly due to asbestos exposure, still remains a diagnostic challenge. Timely diagnosis is imperative to define the most suitable therapeutic approach for the patient, but the choice of diagnostic modalities depends on operator experience and local facilities while bearing in mind the yield of each diagnostic procedure. Since the analysis of pleural fluid cytology is not sufficient in differentiating historical features in PM, histopathological and morphological features obtained via tissue biopsies are fundamental. The quality of biopsy samples is crucial and often requires highly qualified expertise. Since adequate tissue biopsy is essential, medical or video-assisted thoracoscopy (MT or VATS) is proposed as the most suitable approach, with the former being a physician-led procedure. Indeed, MT is the diagnostic gold standard for malignant pleural pathologies. Moreover, this medical or surgical approach can allow diagnostic and therapeutic procedures: it provides the possibility of video-assisted biopsies, the drainage of high volumes of pleural fluid and the administration of sterile calibrated talcum powder under visual control in order to achieve pleurodesis, placement of indwelling pleural catheters if required and in a near future potential intrapleural therapy. In this context, dedicated diagnostic pathways remain a crucial need, especially to quickly and properly diagnose PM. Lastly, the interdisciplinary approach and multidisciplinary collaboration should always be implemented in order to direct the patient to the best customised diagnostic and therapeutic pathway. At the present time, the diagnosis of PM remains an unsolved problem despite MDT (multidisciplinary team) meetings, mainly because of the lack of standardised diagnostic work-up. This review aims to provide an overview of diagnostic procedures in order to propose a clear strategy.

Image-Assısted Pleural Needle Biopsy or Medical Thoracoscopy: Which Method for Which Patient? A Randomızed Controlled Trial

BACKGROUND

Image-guided or assisted needle biopsies and the increasing use of medical thoracoscopy (MT) have increased the diagnostic accuracy of pleural diseases significantly. However, no consensus exists regarding which patients with pleural effusion should undergo MT and which patients should undergo image-guided or assisted needle biopsy as the first procedure to ensure greater diagnostic accuracy.

RESEARCH QUESTION

Which biopsy method is more appropriate for which patient to provide the highest diagnostic accuracy in the diagnosis of pleural effusion?

STUDY DESIGN AND METHODS

This prospective, randomized, parallel study included 228 patients with undiagnosed exudative pleural effusion. Patients were divided into two groups based on CT scan findings. Group 1 included patients with pleural effusion only. Group 2 included patients with pleural thickening or lesion in addition to pleural effusion. Patients in each group were assigned randomly to an image-assisted Abrams needle pleural biopsy (IA-ANPB) or MT arm. The diagnostic sensitivity, reliability, and safety were determined for both groups.

RESULTS

The false-negative rate was 30.3% for the IA-ANPB arm and 3.1% for the MT arm in group 1. The same rates were 11.9% for IA-ANPB and 4.7% for MT in group 2. In group 1, the sensitivity for the IA-ANPB arm was 69.7%, and the negative likelihood ratio was 0.30. The same rates for the MT arm were 96.9% and 0.03 (P = .009). In group 2, these values were 88.1% and 0.12 for the IA-ANPB arm and 95.4% and 0.05 for the MT arm (P = .207). The rate of complications between the two biopsy methods was not different (8.5% and 15.8%, respectively; P = .107).

INTERPRETATION

MT showed a high diagnostic success in all patients with pleural fluid. However, IA-ANPB showed similar diagnostic success as MT in patients with pleural effusion and associated pleural thickening or lesions. Therefore, in the latter case, IA-ANPB could be preferable to MT.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT05428891; URL: www.

CLINICALTRIALS

gov.

Comparative Evaluation of Chest Ultrasonography and Computed Tomography as Predictors of Malignant Pleural Effusion: A Prospective Study

Malignant pleural effusion (MPE) is a manifestation of advanced cancer that requires a prompt and accurate diagnosis. Ultrasonography (US) and computed tomography (CT) are valuable imaging techniques for evaluating pleural effusions; however, their relative predictive ability for a malignant origin remains debatable. This prospective study aimed to compare chest US with CT findings as predictors of malignancy in patients with undiagnosed exudative pleural effusion. Fifty-four adults with undiagnosed exudative pleural effusions underwent comprehensive clinical evaluation including chest US, CT, and histopathologic biopsy. Blinded radiologists evaluated the US and CT images for features suggestive of malignancy, based on predefined criteria. Diagnostic performance measures were calculated using histopathology as a reference standard. Of the 54 patients, 33 (61.1%) had MPEs confirmed on biopsy. No significant differences between US and CT were found in detecting parietal pleural abnormalities, lung lesions, chest wall invasion, or liver metastasis. US outperformed CT in identifying diaphragmatic pleural thickening ≥10 mm (33.3% vs. 6.1%, p < 0.001) and nodularity (45.5% vs. 3%, p < 0.001), whereas CT was superior for mediastinal thickening (48.5% vs. 15.2%, p = 0.002). For diagnosing MPE, diaphragmatic nodularity detected by US had 45.5% sensitivity and 100% specificity, whereas CT mediastinal thickening had 48.5% sensitivity and 90.5% specificity. Both US and CT demonstrate reasonable diagnostic performance for detecting MPE, with particular imaging findings favoring a malignant origin. US may be advantageous for evaluating diaphragmatic pleural involvement, whereas CT is more sensitive to mediastinal abnormalities.

Exploratory pilot study to characterize the immune landscapes of malignant pleural effusions and their corresponding primary tumors from patients with breast carcinoma and lung adenocarcinoma

INTRODUCTION

Malignant pleural effusion (MPE) is a frequent complication of advanced malignancies. In this pilot study, we characterized the immune landscapes of MPEs, compared them to their primary tumor (PT) samples from breast carcinoma (BC) and lung adenocarcinoma (LADC), and tested the utility of multiplexed image technology in cytological samples.

MATERIALS AND METHODS

We evaluated the immune contexture of 6 BC and 5 LADC MPEs and their PTs using 3 multiplex immunofluorescence panels. We explored the associations between sample characteristics and pleural effusion-free survival.

RESULTS

No MPE samples had positive programmed death-ligand 1 expression in malignant cells, although 3 of 11 PTs has positive programmed death-ligand 1 expression (more than 1% expression in malignant cells). Overall, in LADC samples, cluster of differentiation 3 (CD3)+ T cells and CD3+CD8+ cytotoxic T cells predominated (median percentages for MPEs versus PTs: 45.6% versus 40.7% and 4.7% versus 6.6%, respectively) compared with BC. CD68+ macrophages predominated in the BC samples (medians for MPEs 61.2% versus PTs for 57.1%) but not in the LADC samples. Generally in PTs, CD3+CD8+ forkhead box P3+ T cells and the median distances from the malignant cells to CD3+CD8+Ki67+ and CD3+ programmed cell death protein 1 + T cells correlated to earlier MPE after PT diagnosis.

CONCLUSIONS

The immune cell phenotypes in the MPEs and PTs were similar within each cancer type but different between BC versus LADC. An MPE analysis can potentially be used as a substitute for a PT analysis, but an expanded study of this topic is essential.

"Diffuse Hot Pleura" in a Case of Recurrent Squamous Cell Carcinoma of the Foot: 18 F-FDG PET/CT Findings

ABSTRACT

Cutaneous squamous cell carcinoma (cSCC) is the second most common nonmelanoma skin cancer. Unlike basal cell carcinoma, regional lymph nodal metastases and subsequent distant site metastases are more common. Up to approximately 2% to 5% of cSCCs can result in distant metastases. Prognosis is dismal, and median survival is distinctly shortened in case of distant metastatic disease. Diffuse pleural metastases with distinctive overarching unilateral involvement are uncommon. Cutaneous SCC commonly metastasizes to lymph nodes, lungs, liver, bones, and skin. Diffuse unilateral pleural metastasis of cSCC of the foot is extremely rare. We report the case of a 54-year-old man with recurrent cSCC. On follow up restaging, 18 F-FDG PET/CT revealed diffuse nodular bipleural (visceral and parietal) hypermetabolic right pleural thickening, which was later biopsied and turned out to be diffuse pleural metastases from cSCC giving appearance of "hot pleura."

Pictorial Review of Pleural Disease: Multimodality Imaging and Differential Diagnosis

The pleura is a thin, smooth, soft-tissue structure that lines the pleural cavity and separates the lungs from the chest wall, consisting of the visceral and parietal pleurae and physiologic pleural fluid. There is a broad spectrum of normal variations and abnormalities in the pleura, including pneumothorax, pleural effusion, and pleural thickening. Pneumothorax is associated with pulmonary diseases and is caused by iatrogenic or traumatic factors. Chest radiography and US help detect pneumothorax with various signs, and CT can also help assess the causes. Pleural effusion occurs in a wide spectrum of diseases, such as heart failure, cirrhosis, asbestos-related diseases, infections, chylothorax, and malignancies. Chest US allows detection of a small pleural effusion and evaluation of echogenicity or septa in pleural effusion. Pleural thickening may manifest as unilateral or bilateral and as focal, multifocal, or diffuse. Various diseases can demonstrate pleural thickening, such as asbestos-related diseases, neoplasms, and systemic diseases. CT, MRI, and fluorodeoxyglucose (FDG) PET/CT can help differentiate between benign and malignant lesions. Knowledge of these features can aid radiologists in suggesting diagnoses and recommending further examinations with other imaging modalities. The authors provide a comprehensive review of the clinical and multimodality imaging findings of pleural diseases and their differential diagnoses. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Pleural Neoplasms-What Could MRI Change?

The primary pleural neoplasms constitute around 10% of the pleural tumors. The currently recommended method for their imaging is CT which has been shown to have certain limitations. Strong development of the MRI within the last two decades has provided us with a number of sequences that could potentially be superior to CT when it comes to the pleural malignancies' detection and characterization. This literature review discusses the possible applications of the MRI as a diagnostic tool in patients with pleural neoplasms. Although selected MRI techniques have been shown to have a number of advantages over CT, further research is required in order to confirm the obtained results, broaden our knowledge on the topic, and pinpoint the sequences most optimal for pleural imaging, as well as the best methods for reading and analysis of the obtained data.

Tips and Tricks in Thoracic Radiology for Beginners: A Findings-Based Approach

This review has the purpose of illustrating schematically and comprehensively the key concepts for the beginner who approaches chest radiology for the first time. The approach to thoracic imaging may be challenging for the beginner due to the wide spectrum of diseases, their overlap, and the complexity of radiological findings. The first step consists of the proper assessment of the basic imaging findings. This review is divided into three main districts (mediastinum, pleura, focal and diffuse diseases of the lung parenchyma): the main findings will be discussed in a clinical scenario. Radiological tips and tricks, and relative clinical background, will be provided to orient the beginner toward the differential diagnoses of the main thoracic diseases.

Impact of photon counting detector CT derived virtual monoenergetic images and iodine maps on the diagnosis of pleural empyema

PURPOSE

The purpose of this study was to evaluate the impact of virtual monoenergetic image (VMI) energies and iodine maps on the diagnosis of pleural empyema with photon counting detector computed tomography (PCD-CT).

MATERIALS AND METHODS

In this IRB-approved retrospective study, consecutive patients with non-infectious pleural effusion or histopathology-proven empyema were included. PCD-CT examinations were performed on a dual-source PCD-CT in the multi-energy (QuantumPlus) mode at 120 kV with weight-adjusted intravenous contrast-agent. VMIs from 40-70 keV obtained in 10 keV intervals and an iodine map was reconstructed for each scan. CT attenuation was measured in the aorta, the pleura and the peripleural fat (between autochthonous dorsal muscles and dorsal ribs). Contrast-to-noise (CNR) and signal-to-noise (SNR) ratios were calculated. Two blinded radiologists evaluated if empyema was present (yes/no), and rated diagnostic confidence (1 to 4; not confident to fully confident, respectively) with and without using the iodine map. Sensitivity, specificity and diagnostic confidence were estimated. Interobserver agreement was estimated using an unweighted Cohen kappa test. A one-way ANOVA was used to compare variables. Differences in sensitivity and specificity between the different levels of energy were searched using McNemar test.

RESULTS

Sixty patients (median age, 60 years; 26 women) were included. A strong negative correlation was found between image noise and VMI energies (r = -0.98; P = 0.001) and CNR increased with lower VMI energies (r = -0.98; P = 0.002). Diagnostic accuracy (96%; 95% CI: 82-100) as well as diagnostic confidence (3.4 ± 0.75 [SD]) were highest at 40 keV. Diagnostic accuracy and confidence at higher VMI energies improved with the addition of iodine maps (P ≤0.001). Overall, no difference in CT attenuation of peripleural fat between patients with empyema and those with pleural effusion was found (P = 0.07).

CONCLUSION

Low VMI energies lead to a higher diagnostic accuracy and diagnostic confidence in the diagnosis of pleural empyema. Iodine maps help in diagnosing empyema only at high VMI energies.

Transthoracic sonographic scores in evaluating the success of different scelerosing modalities in patients with malignant pleural effusion

Background

Malignant pleural effusions (MPE) mostly arises from metastases to the pleura from other sites. Management of malignant effusions aims to palliate dyspnea and prevent the reaccumulation of pleural fluid to improve patients’ quality of life. Pleurodesis is the most common palliative treatment for patients with refractory MPE. This study was carried out to evaluate the performance of transthoracic sonographic (TUS) scores (pleural sliding and pleural adherence score) in predicting the success of pleurodesis by different modalities in patients with malignant pleural effusion. One hundred malignant pleural effusion patients were enrolled to an interventional clinical trial from September 2019 to April 2021 for palliative management of dyspnea. Pleurodesis for palliative treatment of dyspnea was done either spontaneously by the intercostal chest tube or by a sclerosing agent such as tetracycline solution or tetracycline poudrage or iodopovidine. Patients were randomly allocated to one of these four groups where each group included 25 patients. Transthoracic ultrasound was performed at baseline, and 1 month after pleurodesis and the lung sliding score and pleural adherence score were evaluated.

Results

Majority of patients (78%) had high baseline lung sliding score (7-8). Post pleurodesis only 11.4% had high scores (p<0.001), also the mean lung sliding score decreased significantly in comparison to the baseline values (p˂ 0.001) in the spontaneous, tetracycline solution, tetracycline poudrage, and iodopovidine groups (7.04 ± 1.02 vs. 4.85 ± 1.60, 7.28± 0.98 vs. 4.48± 1.75, 7.20±0.96 vs. 4.44 ± 1.45, 7.04±0.93 vs. 3.35±1.81, respectively). Iodopovidine pleurodesis group in comparison to the other modalities showed the highest pleural adherence score (12.64 ± 2.98) and absent lung sliding in 72.7% of cases and 70 % success rate. Pleural adherence score at cut off ≥ 12 showed 92.75% sensitivity, 89.47% specificity, 92.1 accuracy, and 0.911 area under the curve (AUC) for predicting successful pleurodesis.

Conclusion

TUS scores is a feasible, bedside, and accurate method to detect the outcome of pleurodesis. Iodopovidone was more effective than tetracycline solution, tetracycline poudrage, and spontaneous pleurodesis.

Trial registration

ClinicalTrials.gov. NCT04074902. Registered on 29 August 2019

Contrast-enhanced ultrasound is helpful for differentiating benign from malignant parietal pleural lesions

INTRODUCTION

To describe the value of contrast-enhanced ultrasound (CEUS) for the differentiation of malignant from benign parietal pleural lesions (PPLs).

MATERIALS AND METHODS

From November 2005 to June 2019, 63 patients with histologically/cytologically confirmed PPLs were investigated by CEUS. On CEUS, the extent of enhancement (EE; marked or reduced/absent) and the homogeneity of enhancement (HE; homogeneous or inhomogeneous) were analyzed retrospectively.

RESULTS

In total, 24/63 lesions were benign, and 39/63 lesions were malignant. On CEUS, 11/24 benign and 36/39 malignant lesions showed a marked enhancement. A marked enhancement was significantly more frequently associated with malignancy compared with benign lesions (p < 0.001). In five cases, due to the absence of enhancement, it was not possible to determine the HE. In the remaining cases, 9/20 benign and 19/38 malignant lesions showed an inhomogeneous enhancement (p = 0.79).

CONCLUSION

On CEUS, marked enhancement was significantly more frequently associated with malignant compared with benign lesions. However, some benign lesions, such as chronic inflammatory processes, may also show a marked enhancement. Therefore, the interpretation of perfusion patterns in these lesions must always take into account the clinical background of the patient.

Value of spectral detector computed tomography to differentiate infected from noninfected thoracoabominal fluid collections

PURPOSE

To investigate the diagnostic value of spectral detector CT (SDCT)-derived virtual non-contrast (VNC), virtual monoenergetic images (VMI) and iodine overlays (IO) for distinguishing infected from noninfected fluid collections (FC) in the chest or abdomen.

METHOD

This retrospective study included 58 patients with venous phase SDCT with 77 FC. For all included FC, microbiological analysis of aspirated fluid served as reference. For quantitative analysis, wall thickness was measured, and (ROI)-based analysis performed within the fluid, the FC's wall (if any) and the aorta. Two radiologists qualitatively evaluated visibility of wall enhancement, diagnostic confidence regarding infection of fluid collection, confidence of CT-guided drainage catheter placement and visibility of anatomical landmarks in conventional images (CI) and VNC, VMI_40keV, IO.

RESULTS

Wall thickness significantly differed between infected (n = 46) and noninfected (n = 31) FC (3.5 ± 1.8 mm vs. 1.4 ± 1.8 mm, AUC = 0.81; p < 0.05). Fluid attenuation and wall enhancement was significantly higher in infected as compared to noninfected FC in all reconstructions (p < 0.05, respectively). Highest AUC regarding A) attenuation in fluid was yielded in CI and VMI_70,80keV (0.75); B) wall enhancement in CI (0.88) followed by iodine concentration (0.86). Contrast-to-noise ratio of wall vs. fluid was highest in VMI_40keV (p < 0.05). All assessed qualitative parameters received significantly higher ratings when using spectral reconstructions vs. CI (p for all <0.05), except for visibility of wall enhancement.

CONCLUSION

Spectral reconstructions improve the assessment of infected from noninfected thoracoabdominal fluid collections and depiction of wall enhancement. Diagnostic performance of the quantitative measurements in spectral reconstructions were comparable with measurements in conventional images.

Setting up a Pleural Disease Service

Pleural disease incidence is continuing to rise internationally and management is becoming increasingly complex. There are now many more options for patients, with access to thoracic ultrasound, image-guided biopsies, indwelling pleural catheters, and local-anesthetic pleuroscopy (thoracoscopy). Safety reports have also highlighted the need for specialist operator knowledge and skill. Consequently, the development of a specialized pleural service can manage patients entirely as an outpatient, limit the number of procedures, and improve patient safety, it also fosters opportunities to enhance specialist procedural skills, engage in clinical research, and reduce the costs of care.

Pleural empyema secondary to nephropleural fistula in complicated pyonephrosis

Pleural empyema of extra pulmonary origin is uncommon and empyema secondary to a fistula between the urinary tract and thorax is extremely rare. We report a case of nephropleural fistula causing massive pleural empyema in a 64-year-old woman with a long history of urological problems, including nephrolitiasis and urinary tract infection. She was admitted with sepsis, fever, chills, tachypnea, productive cough and pyuria. At clinical examination, breath sounds were reduced over the left hemithorax. CT revealed a fistulous connection from the upper left calyceal group and the pleural space. Drainage of thoracic and perinephric collection was carried out, but nephrectomy and pleural decortication were required due to haemopurulent urine and decreased hemoglobin levels during the hospitalization. This case demonstrates the unusual and prolonged evolution of an obstructive hydroureteronephrosis complicated by pyonephrosis, culminating in retroperitoneal abscess that fistulized into the pleural space, leading to empyema.

The role of ultrasound in determining the amount of pleural effusion

Background

There is no standardized system to evaluate pleural effusion size on ultrasound (US). We aimed to explore the role of US in determining the amount of pleural effusion, with an attempt to provide evidence for clinical efficacy evaluation and treatment program selection.

Methods

A total of 98 patients undergoing thoracoscopy at our center were enrolled in this study. The patients take a sitting position, then the maximum depths of the pleural effusion by US at the subscapular line, posterior axillary line, midaxillary line, anterior axillary line, and midclavicular line, as well as the maximum thickness of the pleural effusion at the subscapular line, were measured before pleural effusion drainage. Then, the corresponding values in the lateral position were also measured. The relationships between the actual pleural effusion amounts and the measurements at these lines were analyzed using the multivariate linear regression model (MLRM).

Results

The regression equation of the group with a pleural effusion amount of 500–1,000 mL in the sitting position showed statistical significance (P=0.001). The P values of the maximum depths at the subscapular line (X₁) and midclavicular line (X₅) and the maximum thickness at the subscapular line (X₆) were below 0.05. Thus, a final model was established using X₁, X₅, and X₆ as the independent variables.

Conclusions

The combination of US examination and MLRM enables the quantitative determination of pleural effusion.

Emerging applications of clinical ultrasonography

In this work, we introduce the numerous emerging areas and frontiers in the use of point-of-care ultrasonography. Of these, we review the following three: 1) the use of clinical ultrasonography in infectious and tropical diseases (we address its usefulness in the diagnosis and follow-up of the main syndromes, in tropical diseases, and in areas with scarce resources); 2) the usefulness of clinical ultrasonography in the assessment of response to volume infusion in severely ill patients (we review basic concepts and the main static and dynamic variables used for this evaluation); and 3) the use of clinical ultrasonography in the assessment of muscle mass in elderly patients with primary sarcopenia (we review the main muscles and measurements used for it).

Emerging applications of clinical ultrasonography

In this work, we introduce the numerous emerging areas and frontiers in the use of point-of-care ultrasonography. Of these, we review the following three: 1) the use of clinical ultrasonography in infectious and tropical diseases (we address its usefulness in the diagnosis and follow-up of the main syndromes, in tropical diseases, and in areas with scarce resources); 2) the usefulness of clinical ultrasonography in the assessment of response to volume infusion in severely ill patients (we review basic concepts and the main static and dynamic variables used for this evaluation); and 3) the use of clinical ultrasonography in the assessment of muscle mass in elderly patients with primary sarcopenia (we review the main muscles and measurements used for it).

Liquid biopsy approaches for pleural effusion in lung cancer patients

Genomic profiling of tumors has become the mainstay for diagnosis, treatment monitoring and a guide to precision medicine. However, in clinical practice, the detection of driver mutations in tumors has several procedural limitations owing to progressive disease and tumor heterogeneity. The current era of liquid biopsy promises a better solution. This diagnostic utility of liquid biopsy has been demonstrated by numerous studies for the detection of cell-free DNA (cfDNA) in plasma for disease diagnosis, prognosis, and prediction. However, cfDNAs are limited in blood circulation and still hurdles to achieve promising precision medicine. Malignant pleural effusion (MPE) is usually detected in advanced lung malignancy, which is rich in tumor cells. Extracellular vesicles and cfDNAs are the two major targets currently explored using MPE. Therefore, MPE can be used as a source of biomarkers in liquid biopsy for investigating tumor mutations. This review focuses on the liquid biopsy approaches for pleural effusion which may be explored as an alternative source for liquid biopsy in lung cancer patients to diagnose early disease progression.

Diagnostic value of ultrasound-guided needle biopsy in undiagnosed pleural effusions: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Undiagnosed pleural effusions (UPEs) are a common problem of respiratory medicine, leading to an increased diagnostic burden globally. However, the most efficient and cost-effective approaches to UPEs remain controversial. This study aimed to assess the diagnostic value of ultrasound-guided needle biopsy (UGNB) in UPEs.

METHODS

We conducted a search of PubMed, Embase, the Cochrane Library and reference lists of retrieved studies with no publication data limitation. Articles that investigated the diagnostic accuracy of UGNB in UPEs were included. The quality of eligible studies was assessed using Quality Assessment of Diagnostic Accuracy Studies-2. The diagnostic value of UGNB was evaluated by calculating the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds rate, and the area under the curve for the summary receiver operating characteristic curve using a random effects model.

RESULTS

Seven studies comprising 165 patients with UPEs met the inclusion criteria. UGNB had a pooled sensitivity of 83% (95% confidence intervals [CI], 75% - 89%), a specificity of 100% (95% CI, 90% - 100%), a positive likelihood ratio of 8.89 (95% CI, 3.29 - 24.02), a negative likelihood ratio of 0.23 (95% CI, 0.16 - 0.33), a diagnostic odds rate of 51.47 (95% CI, 14.70 - 180.16), and an area under the curve of 0.94. Six pneumothorax cases (3.6%), 5 local wound infections (3.0%), and 1 empyema case (less than 1%) were observed. There was no significant heterogeneity or publication bias in this study.

CONCLUSIONS

Based on current evidence, UGNB is a safe and convenient procedure with a high accuracy for diagnosing UPEs. However, physicians should still be cautious in interpreting negative UGNB results.

The role of imaging in malignant pleural mesothelioma: an update after the 2018 BTS guidelines

Malignant pleural mesothelioma (MPM) is a primary malignancy of the pleura and is associated with a poor outcome. The symptoms and signs of malignant mesothelioma present late in the natural history of the disease and are non-specific, making the diagnosis challenging and imaging key. In 2018, the British Thoracic Society (BTS) updated the guideline on diagnosis, staging, and follow-up of patients with MPM. These recommendations are discussed in this review of the current literature on imaging of MPM. It is estimated MPM will continue to cause serious morbidity and mortality in the UK late into the 21st century, and internationally, people continue to be exposed to asbestos. We aim to update the reader on current and future imaging strategies, which could aid early diagnosis of pleural malignancy and provide an update on staging and assessment of tumour response.

Diffusion-Weighted Imaging Can Differentiate between Malignant and Benign Pleural Diseases

It is not clear whether magnetic resonance imaging (MRI) is useful for the assessment of pleural diseases. The aim of this study is to determine whether diffusion-weighted magnetic resonance imaging (DWI) can differentiate malignant pleural mesothelioma (MPM) from pleural dissemination of lung cancer, empyema or pleural effusion. The DWI was calibrated with the b value of 0 and 800 s/mm². There were 11 MPMs (8 epithelioid and 3 biphasic), 10 pleural disseminations of lung cancer, 10 empyemas, and 12 pleural effusions. The apparent diffusion coefficient (ADC) of the pleural diseases was 1.22 ± 0.25 × 10⁻³ mm²/s in the MPMs, 1.31 ± 0.49 × 10⁻³ mm²/s in the pleural disseminations, 2.01 ± 0.45 × 10⁻³ mm²/s in the empyemas and 3.76 ± 0.62 × 10⁻³ mm²/s in the pleural effusions. The ADC of the MPMs and the pleural disseminations were significantly lower than the ADC of the empyemas and the pleural effusions. Concerning the diffusion pattern of DWI, all 11 MPMs showed strong continuous diffusion, 9 of 10 pleural disseminations showed strong scattered diffusion and 1 pleural dissemination showed strong continuous diffusion, all 10 empyemas showed weak continuous diffusion, and all 12 pleural effusions showed no decreased diffusion. DWI can evaluate pleural diseases morphologically and qualitatively, and thus differentiate between malignant and benign pleural diseases.

Ultrasound-guided pleural cutting needle biopsy: accuracy and factors influencing diagnostic yield

Background

The aim of this study was to retrospectively investigate the diagnostic accuracy of ultrasound-guided pleural cutting needle biopsy (US-guided PCNB) and the potential factors influencing diagnostic yield.

Methods

From July 2014 to June 2016, a total of 147 percutaneous US-guided PCNBs in 144 patients were retrospectively reviewed. The final diagnosis was confirmed by histopathological analysis and follow-up. We calculated diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) and divided all cases into group of correct diagnoses (true-positive and true-negative cases) and group of incorrect diagnoses (false-positive, false-negative, and inconclusive cases). Univariate and multivariate logistic regression analyses were performed to analyze the differences of influencing factors (patient, pleura, and biopsy-associated factors) in the between the two groups.

Results

Seven patients were excluded because of loss to follow-up. A total of 140 cases were ultimately included (105 males and 35 females). There were 105 cases in the correct diagnosis group, and 35 cases in the incorrect diagnosis group. The overall accuracy of US-PCNB was 75.0% and the sensitivity, specificity, PPV, NPV in malignant diagnosis were 58.1%, 99.0%, 96.2%, and 84.2%, respectively. On univariate analysis, variables affecting diagnostic accuracy of US-PCNB were the pleural thickness (<3 mm in thickness 61.0%, ≥3 mm in thickness 85.2%; P=0.001), morphology (non-nodular pleura 71.4%, nodular pleura 95.2%; P=0.026), and needle size (18 G 69.1%, 16 G 87.0%; P=0.022). Finally multivariate logistic regression demonstrated that pleural thickness [odds ratio (OR): 0.278, P=0.003] and needle size (OR: 0.291, P=0.018) independently predicted diagnostic accuracy.

Conclusions

Pleural thickness and the size of the biopsy needle were significantly correlated with the diagnostic yield.

MR Imaging of Pleural Neoplasms

The pleura may be affected by primary tumors or metastatic spread of intrathoracic or extrathoracic neoplasms. Primary pleural neoplasms represent ∼10% of all pleural tumors, and malignant lesions are more common than benign lesions. The most common primary tumors include malignant pleural mesothelioma and solitary fibrous tumor. Although pleural neoplasms may initially be evaluated with computed tomography (CT) and/or fluorodeoxyglucose positron emission tomography (PET)/CT, magnetic resonance (MR) imaging is complementary to these other imaging modalities for disease staging and evaluation of patients. In this article, we discuss the etiology, clinical presentation, and imaging of pleural neoplasms, with specific attention given to the role of MR imaging.

Ultrasonographic quantification of pleural effusion: comparison of four formulae

PURPOSE

The purpose of this study was to evaluate the correlations of ultrasonographically estimated volumes of pleural fluid with the actual effusion volume in order to determine the most reliable formula.

METHODS

In 32 consecutive patients with clinically diagnosed pleural effusion, an ultrasound estimation was made of the volume of effusion using four different formulae, including two in the erect position and two in the supine position. Closed-tube thoracostomy drainage using a 28-Fr chest tube was performed. The total drainage was calculated after confirmation of full lung re-expansion and complete drainage by plain chest radiographs and ultrasound. The ultrasonographically estimated volume was compared to the actual total volume drained as the gold standard.

RESULTS

There were 14 female and 18 male subjects. The mean age of all subjects was 41.56±18.34 years. Fifty percent of the effusions were in the left hemithorax. Metastatic disease accounted for the plurality of effusions (31.2%). The mean total volume drained for all the subjects was 2,770±1,841 mL. The ultrasonographically estimated volumes for the erect 1, erect 2, supine 1, and supine 2 formulae were 1,816±753 mL, 1,520±690 mL, 2,491±1,855 mL, and 1,393±787 mL, respectively. The Pearson correlation coefficients (r) for the estimate of each formula were 0.75, 0.81, 0.62, and 0.63, respectively.

CONCLUSION

Although both erect formulae showed similar correlations, the erect 2 formula (Goecke 2) was most closely correlated with the actual volume drained.

Video assisted thoracoscopic and open chest surgery in diagnosis and treatment of malignant pleural diseases

Parenchymal cancers of lung, breast, gastrointestinal tract and ovaries as well as lymphomas and mesotheliomas are among the most common cancer types causing malignant effusions, though almost all tumour types have been reported to cause a malignant effusion. The prognosis heavily depends on patients' response to systemic therapy however, regardless of the causing pathology and histopathologic form, malignant pleural disease is normally associated with a poor prognosis. To date, there are not sufficient data to allow accurate predictions of survival that would facilitate decision making for managing patients with malignant pleural diseases. Interventions are directed towards drainage of the effusion and, when appropriate, concurrent or subsequent pleurodesis or establishing long-term drainage to prevent re-accumulation. The rate of re-accumulation of the pleural effusion, the patient's prognosis, and the severity of the patient's symptoms should guide the subsequent choice of therapy. In contemporary medicine, not many cancers have managed to generate as intense debates concerning treatment, as malignant pleural mesothelioma. The relative advantages of surgery, radiation, chemotherapy and any combination of the three are continuously reassessed and reconsidered, even though not always based on scientific evidence. The aim of surgery in mesothelioma may be prolongation of life, in addition to palliation of symptoms. Longer recovery periods from more extensive surgical procedures could be justified, in carefully selected patients. Surgical options include: Video assisted thoracoscopic (VATS) pleurodesis, VATS partial pleurectomy (VATS PP)-both parietal and visceral; open pleurectomy decortication (PD)-with an extended option (EPD) and extrapleural pneumonectomy (EPP). Current evidence implies that EPD can be performed reliably in specialised centres with good results, both in terms of mortality and survival; however, no operation has yet been shown to be beneficial in a prospective randomized controlled clinical trial.

Diagnosis and management options in malignant pleural effusions

Malignant pleural effusion (MPE) denotes an advanced malignant disease process. Most of the MPE are metastatic involvement of the pleura from primary malignancy at lung, breast, and other body sites apart from lymphomas. The diagnosis of MPE has been traditionally made on cytological examination of pleural fluid and/or histological examination of pleural biopsy tissue that still remains the initial approach in these cases. There has been tremendous advancement in the diagnosis of MPE now a day with techniques i.e. characteristic Ultrasound and computed tomography features, image guided biopsies, fluorodeoxyglucose-positron emission tomography imaging, thoracoscopy with direct biopsy under vision, tumor marker studies and immunocytochemical analysis etc., that have made possible an early diagnosis of MPE. The management of MPE still remains a challenge to pulmonologist and oncologist. Despite having various modalities with better tolerance such as pleurodesis and indwelling pleural catheters etc., for long-term control, all the management approaches remain palliative to improve the quality of life and reduce symptoms. While choosing an appropriate management intervention, one should consider the clinical status of the patient, life expectancy, overall cost, availability and comparative institutional outcomes, etc.

Current best practice in the evaluation and management of malignant pleural effusions

Malignant pleural effusions (MPEs) are an important cause of cancer-related mortality and morbidity. It is a heterogeneous group of conditions, which leads to debilitating symptoms and confers a poor prognosis. Recent well-designed randomized trials have provided a broader evidence base for an expanding range of treatment options. Together, with new prognostic scoring systems and a greater understanding of how different patient phenotypes respond to treatment, this allows greater personalization of management. This article will discuss the current evidence on evaluation and management of MPEs.

Multidetector CT Findings and Differential Diagnoses of Malignant Pleural Mesothelioma and Metastatic Pleural Diseases in Korea

Objective

To compare the multidetector CT (MDCT) features of malignant pleural mesothelioma (MPM) and metastatic pleural disease (MPD).

Materials and Methods

The authors reviewed the MDCT images of 167 patients, 103 patients with MPM and 64 patients with MPD. All 167 cases were pathologically confirmed by sonography-guided needle biopsy of pleura, thoracoscopic pleural biopsy, or open thoracotomy. CT features were evaluated with respect to pleural effusion, pleural thickening, invasion of other organs, lung abnormality, lymphadenopathy, mediastinal shifting, thoracic volume decrease, asbestosis, and the presence of pleural plaque.

Results

Pleural thickening was the most common CT finding in MPM (96.1%) and MPD (93.8%). Circumferential pleural thickening (31.1% vs. 10.9%, odds ratio [OR] 3.670), thickening of fissural pleura (83.5% vs. 67.2%, OR 2.471), thickening of diaphragmatic pleura (90.3% vs. 73.4%, OR 3.364), pleural mass (38.8% vs. 23.4%, OR 2.074), pericardial involvement (56.3% vs. 20.3%, OR 5.056), and pleural plaque (66.0% vs. 21.9%, OR 6.939) were more frequently seen in MPM than in MPD. On the other hand, nodular pleural thickening (59.2% vs. 76.6%, OR 0.445), hilar lymph node metastasis (5.8% vs. 20.3%, OR 0.243), mediastinal lymph node metastasis (10.7% vs. 37.5%, OR 0.199), and hematogenous lung metastasis (9.7% vs. 29.2%, OR 0.261) were less frequent in MPM than in MPD. When we analyzed MPD from extrathoracic malignancy (EMPD) separately and compared them to MPM, circumferential pleural thickening, thickening of interlobar fissure, pericardial involvement and presence of pleural plaque were significant findings indicating MPM than EMPD. MPM had significantly lower occurrence of hematogenous lung metastasis, as compared with EMPD.

Conclusion

Awareness of frequent and infrequent CT findings could aid in distinguishing MPM from MPD.

The Third Italian Consensus Conference for Malignant Pleural Mesothelioma: State of the art and recommendations

Malignant Pleural Mesothelioma (MPM) remains a relevant public health issue, and asbestos exposure is the most relevant risk factor. The incidence has considerably and constantly increased over the past two decades in the industrialized countries and is expected to peak in 2020-2025. In Italy, a standardized-rate incidence in 2011 among men was 3.5 and 1.25 per 100,000 in men and women, respectively, and wide differences are noted among different geographic areas. The disease remains challenging in terms of diagnosis, staging and treatment and an optimal strategy has not yet been clearly defined. The Third Italian Multidisciplinary Consensus Conference on Malignant Pleural Mesothelioma was held in Bari (Italy) in January 30-31, 2015. This Consensus has provided updated recommendations on the MPM management for health institutions, clinicians and patients.

Pleural controversies: image guided biopsy vs. thoracoscopy for undiagnosed pleural effusions?

Undiagnosed pleural effusions present an increasing diagnostic burden upon healthcare providers internationally. The investigation of pleural effusions often requires the acquisition of tissue for histological analysis and diagnosis. Historically there were two options for tissue biopsy: a 'gold standard' surgical biopsy or a "blind" closed pleural biopsy. Over the last decade however, image-guided Tru-cut biopsies and local anaesthetic thoracoscopic (local anaesthetic thoracoscopy) biopsies have become more widespread. Image-guided techniques acquire samples under ultrasound (US) or computed tomography (CT) guidance whereas LAT involves the direct visualisation and biopsy of the pleura with pleuroscopy. Both techniques have been shown to be superior to 'blind' closed pleural biopsy for the diagnosis of pleural or metastatic malignancy. However, closed biopsy remains a viable method of investigation in areas of high incidence of tuberculosis (TB). Beyond this, each investigative technique has its own advantages and disadvantages. Image-guided biopsy is less invasive, usually carried out as an outpatient procedure, and enables tissue biopsy in frail patients and those with pleural thickening but no pleural fluid. Local anaesthetic thoracoscopy (LAT) provides diagnostic and therapeutic capabilities in one procedure. Large volume thoracentesis, multiple pleural biopsies and talc poudrage can be carried out in a single procedure. The overall diagnostic yield is similar for both techniques, although there are no large-scale direct comparisons. Both techniques share low complication rates.

Ultrasound for the diagnosis of infectious diseases: Approach to the patient at point of care and at secondary level

Bedside ultrasound evaluation for infection can be performed promptly at the bedside, using simple equipment and without irradiation. Visualization of the foci often enables prompt antimicrobial therapy and even early ultrasound-guided procedure, facilitating earlier confirmation. These procedures are made safer using the real-time visual control that ultrasound provides. Future challenges for an infectious diseases specialist include gaining experience about the appropriate use of point-of-care ultrasound (POCUS). Ultrasonography training is required to ensure competent use of this technology.

Diagnostic tools of pleural effusion

Pleural effusion is not a rare disease in Korea. The diagnosis of pleural effusion is very difficult, even though the patients often complain of typical symptoms indicating of pleural diseases. Pleural effusion is characterized by the pleural cavity filled with transudative or exudative pleural fluids, and it is developed by various etiologies. The presence of pleural effusion can be confirmed by radiological studies including simple chest radiography, ultrasonography, or computed tomography. Identifying the causes of pleural effusions by pleural fluid analysis is essential for proper treatments. This review article provides information on the diagnostic approaches of pleural effusions and further suggested ways to confirm their various etiologies, by using the most recent journals for references.

Diagnostic accuracy of 18F-FDG-PET and PET/CT in the differential diagnosis between malignant and benign pleural lesions: a systematic review and meta-analysis

RATIONALE AND OBJECTIVES

To systematically review and meta-analyze published data about the diagnostic accuracy of fluorine-18-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) and PET/computed tomography (CT) in the differential diagnosis between malignant and benign pleural lesions.

METHODS AND MATERIALS

A comprehensive literature search of studies published through June 2013 regarding the diagnostic performance of (18)F-FDG-PET and PET/CT in the differential diagnosis of pleural lesions was carried out. All retrieved studies were reviewed and qualitatively analyzed. Pooled sensitivity, specificity, positive and negative likelihood ratio (LR+ and LR-) and diagnostic odds ratio (DOR) of (18)F-FDG-PET or PET/CT in the differential diagnosis of pleural lesions on a per-patient-based analysis were calculated. The area under the summary receiver operating characteristic curve (AUC) was calculated to measure the accuracy of these methods. Subanalyses considering device used (PET or PET/CT) were performed.

RESULTS

Sixteen studies including 745 patients were included in the systematic review. The meta-analysis of 11 selected studies provided the following results: sensitivity 95% (95% confidence interval [95%CI]: 92-97%), specificity 82% (95%CI: 76-88%), LR+ 5.3 (95%CI: 2.4-11.8), LR- 0.09 (95%CI: 0.05-0.14), DOR 74 (95%CI: 34-161). The AUC was 0.95. No significant improvement of the diagnostic accuracy considering PET/CT studies only was found.

CONCLUSIONS

(18)F-FDG-PET and PET/CT demonstrated to be accurate diagnostic imaging methods in the differential diagnosis between malignant and benign pleural lesions; nevertheless, possible sources of false-negative and false-positive results should be kept in mind.

Imaging the pleura

Pleural disease is now recognized as an important subspecialty of pulmonary medicine, with increasing provision being made for specialist services and procedures. In response, the field of pleural imaging has advanced in recent years, especially with regard to ultrasound. Salient multimodality imaging techniques are discussed.

The diagnosis and management of pleural effusions in the ICU

Pleural effusions are common in critically ill patients. Most effusions in intensive care unit (ICU) patients are of limited clinical significance; however, some are important and require aggressive management. Transudative effusions in the ICU are commonly caused by volume overload, decreased plasma oncotic pressure, and regions of altered pleural pressure attributable to atelectasis and mechanical ventilation. Exudates are sequelae of pulmonary or pleural infection, pulmonary embolism, postsurgical complications, and malignancy. Increases in pleural fluid volume are accommodated principally by chest wall expansion and, to a lesser degree, by lung collapse. Studies in mechanically ventilated patients suggest that pleural fluid drainage can result in improved oxygenation for up to 48 hours, but data on clinical outcomes are limited. Mechanically ventilated patients with pleural effusions should be semirecumbant and treated with higher levels of positive-end expiratory pressure. Rarely, large effusions can cause cardiac tamponade or tension physiology, requiring urgent drainage. Bedside ultrasound is both sensitive and specific for diagnosing pleural effusions in mechanically ventilated patients. Sonographic findings of septation and homogenous echogenicity may suggest an exudative effusion, but definitive diagnosis requires pleural fluid sampling. Thoracentesis should be carried out under ultrasound guidance. Antibiotic regimens for parapneumonic effusions should be based on current pneumonia guidelines, and anaerobic coverage should be included in the case of empyema. Decompression of the pleural space may be necessary to improve respiratory mechanics, as well as to treat complicated effusions. While small-bore catheters inserted under ultrasound guidance may be used for nonseptated effusions, surgical consultation should be sought in cases where this approach fails, or where the effusion appears complex and septated at the outset. Further research is needed to determine the effects of pleural fluid drainage on clinical outcomes in mechanically ventilated patients, to evaluate weaning strategies that include pleural fluid drainage, and to better identify patients in whom pleural effusions are more likely to be infected.

Incidental pleural effusions detected on screening breast MRI

OBJECTIVE

Pleural effusions are a common complication of malignancy that must be differentiated from physiologic effusions identified on breast MRI. This study aimed to determine the incidence and reference range of physiologic pleural effusions observed in healthy women undergoing screening breast MRI.

MATERIALS AND METHODS

A retrospective analysis of 200 consecutive women who underwent screening breast MRI between December 2007 and December 2008 was performed. Medical records were reviewed; patients with abnormal MRI findings resulting in a diagnosis of breast cancer, a prior malignancy, or cardiac or pulmonary disease were excluded. Patient age, the presence of pleural effusions, and, if present, the laterality were recorded. The largest size of effusions was measured at the anterior chest wall. A nonparametric Wilcoxon test was used to compare the sizes of right- and left-sided pleural effusions.

RESULTS

Of the 200 patients, 174 (87%) had a pleural effusion; 124 (62%) were bilateral and 50 (25%) were unilateral. Compared with the left side, right-sided pleural effusions were more frequent (81.5% vs 67.5%, respectively; p < 0.001) and were slightly larger (mean, 3.3 vs 2.8 mm; p = 0.019). Effusions ranged from 1 to 12 mm on the right and from 1 to 8 mm on the left. The reference range for pleural effusions on breast MRI based on this healthy population is up to 7 mm on the right side and 5 mm on the left side.

CONCLUSION

Small pleural effusions are a common physiologic finding in women undergoing screening breast MRI and should not prompt further testing.

Pleural effusion: diagnosis, treatment, and management

A pleural effusion is an excessive accumulation of fluid in the pleural space. It can pose a diagnostic dilemma to the treating physician because it may be related to disorders of the lung or pleura, or to a systemic disorder. Patients most commonly present with dyspnea, initially on exertion, predominantly dry cough, and pleuritic chest pain. To treat pleural effusion appropriately, it is important to determine its etiology. However, the etiology of pleural effusion remains unclear in nearly 20% of cases. Thoracocentesis should be performed for new and unexplained pleural effusions. Laboratory testing helps to distinguish pleural fluid transudate from an exudate. The diagnostic evaluation of pleural effusion includes chemical and microbiological studies, as well as cytological analysis, which can provide further information about the etiology of the disease process. Immunohistochemistry provides increased diagnostic accuracy. Transudative effusions are usually managed by treating the underlying medical disorder. However, a large, refractory pleural effusion, whether a transudate or exudate, must be drained to provide symptomatic relief. Management of exudative effusion depends on the underlying etiology of the effusion. Malignant effusions are usually drained to palliate symptoms and may require pleurodesis to prevent recurrence. Pleural biopsy is recommended for evaluation and exclusion of various etiologies, such as tuberculosis or malignant disease. Percutaneous closed pleural biopsy is easiest to perform, the least expensive, with minimal complications, and should be used routinely. Empyemas need to be treated with appropriate antibiotics and intercostal drainage. Surgery may be needed in selected cases where drainage procedure fails to produce improvement or to restore lung function and for closure of bronchopleural fistula.