Randomised controlled trial to compare the diagnostic yield of positron emission tomography CT (PET-CT) TARGETed pleural biopsy versus CT-guided pleural biopsy in suspected pleural malignancy (TARGET trial)

PET-CT-guided versus CT-guided biopsy in suspected malignant pleural thickening: a randomised trial

BACKGROUND

Pleural biopsy is the gold standard for diagnosis of pleural malignancy but a significant proportion will have an inconclusive biopsy despite ongoing clinical suspicion of malignancy. We investigated whether positron emission tomography-computed tomography (PET-CT) targeted pleural biopsy is superior to standard CT-guided pleural biopsy following an initial non-diagnostic biopsy.

METHODS

The TARGET trial was a multicentre, parallel group randomised trial. Patients with a previous inconclusive pleural biopsy but an ongoing suspicion of pleural malignancy were randomised (1:1) to receive either CT-guided biopsy (standard care) or PET-CT followed by a targeted CT biopsy (intervention). The primary outcome was pleural malignancy correctly identified from the trial biopsy.

RESULTS

Between September 2015 and September 2018, 59 participants were randomised from eight UK hospital sites: 29 to CT-only followed by targeted biopsy and 30 to PET-CT followed by targeted biopsy. The proportion of pleural malignancy correctly identified was similar between the groups (risk ratio 1.03 (95% CI 0.83-1.29); p=0.77). The sensitivity of the trial biopsy to identify pleural malignancy was 79% (95% CI 54-94%) in the CT-only group versus 81% (95% CI 54-96%) in the PET-CT group.

CONCLUSIONS

The results do not support the practice of PET-CT to guide pleural biopsies in patients with a previous non-diagnostic biopsy. The diagnostic sensitivity in the CT-only group was higher than anticipated and supports the practice of repeating a CT-guided biopsy following an inconclusive result if clinical suspicion of malignancy persists.

Malignant pleural disease

Malignant pleural disease represents a growing healthcare burden. Malignant pleural effusion affects approximately 1 million people globally per year, causes disabling breathlessness and indicates a shortened life expectancy. Timely diagnosis is imperative to relieve symptoms and optimise quality of life, and should give consideration to individual patient factors. This review aims to provide an overview of epidemiology, pathogenesis and suggested diagnostic pathways in malignant pleural disease, to outline management options for malignant pleural effusion and malignant pleural mesothelioma, highlighting the need for a holistic approach, and to discuss potential challenges including non-expandable lung and septated effusions.

Prognostic value of 18F-FDG PET/CT in malignant pleural mesothelioma: a meta-analysis

BACKGROUND

Several FDG PET/CT parameters have been utilized to evaluate the prognosis in malignant pleural mesothelioma (MPM). However, there are still controversial results due to the low incidence of MPM.

PURPOSE

To assess the prognostic value of 18F-FDG PET/CT in MPM.

MATERIAL AND METHODS

A systematic literature search was performed in PubMed, Embase, Medline, and The Cochrane Library to identify eligible studies from inception to 12 February 2020. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) of several variables, such as maximum standardized uptake value (SUV_max), the reduction of SUV_max after treatment (ΔSUV_max), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and the reduction of TLG after treatment (ΔTLG), were calculated. Meta-regression with subsequent subgroup analyses were conducted to determine the heterogeneity of cutoff values, treatment regimen, study design, uptake time, and scanners across various studies.

RESULTS

In total, 19 eligible studies including 1819 patients were enrolled in the meta-analysis. The univariate analysis showed that the pooled HRs (95% CI) of SUV_max, ΔSUV_max, MTV, TLG, and ΔTLG were 1.29 (1.16-1.42), 1.12 (1.05-1.19), 1.15 (1.00-1.33), 1.47 (1.23-1.76), and 1.27 (1.12-1.45), respectively. The multivariate analysis showed that the pooled HRs (95% CI) of SUV_max, ΔSUV_max, MTV, and TLG for overall survival (OS) were 1.20 (1.08-1.33), 1.10 (1.02-1.19), 0.95 (0.81-1.11), and 1.13 (1.08-1.18), respectively.

CONCLUSION

SUV_max, ΔSUV_max, TLG, and ΔTLG are significant prognostic indicators for OS, while more clinical studies are needed to confirm the prognostic value of MTV in MPM.

Could Maximum SUV be Used as Imaging Guidance in Large Lung Lesions Biopsies? Double Sampling Under PET-CT/XperGuide Fusion Imaging in Inhomogeneous Lung Uptaking Lesions to Show That it can Make a Difference

Introduction: The purpose of this study is to evaluate the diagnostic value of positron emission computed tomography-cone beam computed tomography (PET/CT-CBCT) fusion guided percutaneous biopsy, targeted to the maximum standardized uptake value (SUVmax) and minimum standardized uptake value (SUVmin) of large lung lesions. Materials and Methods: Inside a larger cohort of PET/CT-CBCT guided percutaneous lung biopsies, 10 patients with large pulmonary lesions (diameter > 30 mm) were selected retrospectively. These patients have been subjected to double biopsy sampling respectively in the SUVmax area and in the SUVmin area of the lesion. Technical success has been calculated. For each sample, the percentage of neoplastic, inflammatory, and fibrotic cells was reported. Furthermore, the possibility of performing immunohistochemical or molecular biology investigations to specifically define the biomolecular tumor profile was analyzed. Results: Nine lesions were found to be malignant, one benign (inflammation). Technical success was 100% (10/10) in the SUVmax samples and 70% (7/10) in the SUVmin samples (P-value: .21). In the first group, higher percentages of neoplastic cells were found at pathologic evaluation, while in the second group areas of inflammation and fibrosis were more represented. The biomolecular profile was obtained in 100% of cases (9/9) of the first group, while in the second group only in 33.3% of cases (2/6), with a statistically significant difference between the 2 groups (P-value: .011). Conclusion: A correlation between the standardized uptake value value and the technical success of the biopsy sample has been identified. PET/CT-CBCT guidance allows to target the biopsy in the areas of the tumor which are richer in neoplastic cells, thus obtaining more useful information for the planning of patient-tailored cancer treatments.

Optimal diagnostic strategies for pleural diseases and identifying high-risk patients

INTRODUCTION

Pleural diseases encompass a broad range of conditions with diverse and heterogenous etiologies. Diagnostics in pleural diseases thus represents a challenging field with a wide array of available testing to distinguish between the numerous causes of pleural disease. Nonetheless, deploying best practice diagnostics in this area is essential in reducing both duration o the investigation pathway and symptom burden.

AREAS COVERED

This article critically appraises the optimal diagnostic strategies and pathway in patients with pleural disease, reviewing the latest evidence and key practice points in achieving a treatable diagnosis in patients with pleural disease. We also cover future and novel directions that are likely to influence pleural diagnostics in the near future. PubMed was searched for articles related to pleural diagnostics (search terms below), with the date ranges including June 2012 to June 2022.

EXPERT OPINION

No single test will ever be sufficient to provide a diagnosis in pleural conditions. The key to reducing procedure burden and duration to diagnosis lies in personalizing the investigation pathway to patients and deploying tests with the highest diagnostic yield early (such as pleural biopsy in infection and malignancy). Novel biomarkers may also allow earlier diagnostic precision in the near future.

Management of Malignant Pleural Effusion: Where Are We Now?

Pleural malignancies are among the most common causes of pleural disease and form the basis of our daily pleural practice. There has been significant research and increase in both diagnostic and therapeutic management of malignant pleural diseases in the last decade. Good-quality data have led to a paradigm shift in the management options of pleural malignancies, and indwelling pleural catheter is now recommended and widely used as first-line intervention. Several trials compared different treatment modalities for pleural malignancies and continue to emphasize the need to reduce hospital length of stay and unnecessary pleural intervention, and the importance of patient choice in clinical decision making. This practical review aims to summarize the current knowledge for the management of pleural malignancies, and the understanding of the steps that we still have to climb to optimize management and reduce morbidity.

Malignant pleural effusion: Updates in diagnosis, management and current challenges

Malignant pleural effusion (MPE) is a common condition which often causes significant symptoms to patients and costs to healthcare systems. Over the past decade, the management of MPE has progressed enormously with large scale, randomised trials answering key questions regarding optimal diagnostic strategies and effective management strategies. Despite a number of management options, including talc pleurodesis, indwelling pleural catheters and combinations of the two, treatment for MPE remains symptom directed and centered around drainage strategy. The future goals for providing improved care for patients lies in changing the treatment paradigm from a generic pathway to personalised care, based on probability of malignancy type and survival. This article reviews the current evidence base, new discoveries and future directions in the diagnosis and management of MPE.

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.

Positron emission tomography-computed tomography (PET-CT) in suspected malignant pleural effusion. An updated systematic review and meta-analysis

The role of PET and integrated PET-CT in the diagnostic workup of suspected malignant pleural effusions is unknown. Earlier systematic reviews (published 2014 and 2015) both included pleural pathology without effusion, and reached contradictory conclusions. Five studies have been published since the latest review. This systematic review and meta-analysis aims to summarise the evidence of PET and integrated PET-CT in predicting pleural malignancy in patients suspected of having malignant pleural effusions. A meta-analysis based on a systematic literature search in Cochrane Library, Medline, EMBASE and Clinicaltrials.gov was performed. Diagnostic studies evaluating the performance of PET or PET-CT in patients with suspected malignant pleural effusion, using pleural fluid cytology or histopathology as the reference test, and presenting sufficient data for constructing a 2x2 table were included. The quality of the studies was assessed by the Quality Assessment of Diagnostic Accuracy Studies-2 score. Subgroup analyses on image modality, interpretation method and known malignancy status pre index-test application were planned. Seven studies with low risk of bias were included. The pooled ability to separate benign from malignant effusions varied with image modality, interpretation method and known malignancy status pre index-test application. In studies using PET-CT, visual/qualitative image analysis was superior to semi-quantitative with positive (LR + ) and negative likelihood ratio (LR-) of 9.9 (4.5-15.3) respectively 0.1 (0.1-0.2). There was considerable heterogeneity among studies. In conclusion, visual/qualitative image analysis of integrated PET-CT seems to add relevant information in the work-up of suspected malignant pleural effusions with LR + and LR- close to rigorous pre-set cut-offs of > 10 and < 0.1. However, the quality of evidence was low due to inter-study heterogeneity, and inability to assess meta-bias. Clinical Trial Registration: The protocol was uploaded to the PROSPERO database (CRD42020213319) on the 13th of October 2020.

Advances in pleural infection and malignancy

Pleural infection and malignancy are among the most common causes of pleural disease and form the mainstay of pleural practice. There has been significant research and increase in scientific understanding in these areas in the past decade. With regard to pleural infection, the rising incidence remains worrying. An increased awareness allowing earlier diagnosis, earlier escalation of therapy and the use of validated risk stratification measures may improve outcomes. In pleural malignancy, research has enabled clinicians to streamline patient pathways with focus on reducing time to diagnosis, definitive management of malignant pleural effusion and achieving these with the minimum number of pleural interventions. Trials comparing treatment modalities of malignant pleural effusion continue to highlight the importance of patient choice in clinical decision-making. This article aims to summarise some of the most recent literature informing current practice in these two areas.

Diagnostics in Pleural Disease

Pleural disease diagnostics represent a sprawling topic that has enjoyed a renaissance in recent years from humble beginnings. Whilst pleural patients are heterogeneous as a population and in the aetiology of the disease with which they present, we provide an overview of the typical diagnostic approach. Pleural fluid analysis is the cornerstone of the diagnostic pathway; however, it has many shortcomings. Strong cases have been made for more invasive upfront investigations, including image-guided biopsies or local anaesthetic thoracoscopy, in selected populations. Imaging can guide the diagnostic process as well as act as a vehicle to facilitate therapies, and this is never truer than with the recent advances in thoracic ultrasound.

Contemporary Approach to the Diagnosis of Malignant Pleural Effusion

Advanced malignancy is a prevalent cause of exudative pleural effusion. The management of malignant pleural effusion (MPE) has been the subject of several recent randomized controlled trials and excellent reviews. Less attention has been focused on another controversial and challenging aspect of MPE: establishing the diagnosis. Before selecting the optimal management strategy, the presence of an MPE must first be correctly identified with an emphasis on minimizing invasiveness and discomfort in a patient with late-stage cancer. The aim of the present review is to summarize the current knowledge about MPE diagnostics and to propose an algorithm for the diagnosis of MPE in established or suspected malignancy.

Malignant Pleural Effusion: Diagnosis and Management

Symptomatic malignant pleural effusion is a common clinical problem. This condition is associated with very high mortality, with life expectancy ranging from 3 to 12 months. Studies are contributing evidence on an increasing number of therapeutic options (therapeutic thoracentesis, thoracoscopic pleurodesis or thoracic drainage, indwelling pleural catheter, surgery, or a combination of these therapies). Despite the availability of therapies, the management of malignant pleural effusion is challenging and is mainly focused on the relief of symptoms. The therapy to be administered needs to be designed on a case-by-case basis considering patient's preferences, life expectancy, tumour type, presence of a trapped lung, resources available, and experience of the treating team. At present, the management of malignant pleural effusion has evolved towards less invasive approaches based on ambulatory care. This approach spares the patient the discomfort caused by more invasive interventions and reduces the economic burden of the disease. A review was performed of the diagnosis and the different approaches to the management of malignant pleural effusion, with special emphasis on their indications, usefulness, cost-effectiveness, and complications. Further research is needed to shed light on the current matters of controversy and help establish a standardized, more effective management of this clinical problem.

Current Applications for Nuclear Medicine Imaging in Pulmonary Disease

Purpose of Review

The main goal of the article is to familiarize the reader with commonly and uncommonly used nuclear medicine procedures that can significantly contribute to improved patient care. The article presents examples of specific modality utilization in the chest including assessment of lung ventilation and perfusion, imaging options for broad range of infectious and inflammatory processes, and selected aspects of oncologic imaging. In addition, rapidly developing new techniques utilizing molecular imaging are discussed.

Recent Findings

The article describes nuclear medicine imaging modalities including gamma camera, SPECT, PET, and hybrid imaging (SPECT/CT, PET/CT, and PET/MR) in the context of established and emerging clinical applications. Areas of potential future development in nuclear medicine are discussed with emphasis on molecular imaging and implementation of new targeted tracers used in diagnostics and therapeutics (theranostics).

Summary

Nuclear medicine and molecular imaging provide many unique and novel options for the diagnosis and treatment of pulmonary diseases. This article reviews current applications for nuclear medicine and molecular imaging and selected future applications for radiopharmaceuticals and targeted molecular imaging techniques.

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.

Advances in pleural effusion diagnostics

Introduction: Pleural effusion is a common clinical problem. Yet, in a significant proportion of patients (~20%), the cause of pleural effusion remains unknown. Understanding the diagnostic value of pleural fluid tests is crucial for the development of accurate diagnostic models.Areas covered: This paper provides an overview of latest advances in the diagnosis of pleural effusion based on the best evidence available.Expert opinion: For pleural fluid tests to have a good diagnostic value, it is necessary that data obtained from clinical history, physical examination, and radiological studies are correctly interpreted. Thoracentesis and pleural biopsy should always be performed under image guidance to improve its diagnostic sensitivity and prevent complications. Nucleic acid amplification tests, pleural tissue cultures, and collection of pleural fluid in blood culture bottles improve the diagnostic yield of pleural fluid cultures. Although undiagnosed pleural effusions generally have a favorable prognosis, follow-up is recommended to prevent the development of a malignant pleural effusion.

The value of computed tomography in discriminating malignant from non-malignant causes of unresolved unilateral pleural effusions: a systematic review

The scientific background in expert-opinion papers for recommending Computed Tomography (CT) in unilateral pleural exudates is based on studies including patients with other findings than unilateral pleural effusions or selected patients undergoing thoracoscopy. Therefore, we performed a systematic review investigating the sensitivity of CT for predicting malignancy in patients with unilateral, non-transudative, pleural effusions. A search strategy was developed with the assistance of a medical information specialist at our university library. We searched PubMed/MEDLINE, EMBASE and Cochrane Library, ClinicalTrials.gov and articles citing the included studies. No date restrictions were applied (the first included paper was published in 2001 (1)), and only literature in English was included. We used the Quality Assessment of Diagnostic Accuracy Studies 2 for bias assessment. We registered the protocol at PROSPERO (CRD42018094830). Five studies were included, two prospective and three retrospective, all performed in Western Europe. No study reported diagnostic values for patients with unilateral, non-transudative pleural effusions only; one study did for unilateral pleural effusions. In the remaining studies, most patients had unilateral effusions and non-transudative effusions. Patients were primarily males and >70 years. All but one study found a high incidence of malignancy, dominated by malignant pleural mesothelioma. All studies were limited by risk of bias and applicability, predominantly regarding study population, pretests and index test. The current evidence supporting the sensitivity of CT for predicting malignancy in unilateral pleural effusions (both non-transudative and all types of effusion) is very low and did not allow meta-analysis. Standardization of patient population and CT protocol may facilitate conclusions of futures studies.