Turning on the light for brain tumor surgery: A 5-aminolevulinic acid story

To aid surgeons in more complete and safe resection of brain tumors, adjuvant technologies have been developed to improve visualization of target tissue. Fluorescence-guided surgery relies on the use of fluorophores and specific light wavelengths to better delineate tumor tissue, inflammation, and areas of blood-brain barrier breakdown. 5-aminolevulinic acid (5-ALA), the first fluorophore developed specifically for brain tumors, accumulates within tumor cells, improving visualization of tumors both at the core, and infiltrative margin. Here, we describe the background of how 5-ALA integrated into the modern neurosurgery practice, clinical evidence for the current use of 5-ALA, and future directions for its role in neurosurgical oncology. Maximal safe resection remains the standard of care for most brain tumors. Gross total resection of high-grade gliomas (HGGs) is associated with greater overall survival and progression-free survival (PFS) in comparison to subtotal resection or adjuvant treatment therapies alone.1-3 A major challenge neurosurgeons encounter when resecting infiltrative gliomas is identification of the glioma tumor margin to perform a radical resection while avoiding and preserving eloquent regions of the brain. 5-aminolevulinic acid (5-ALA) remains the only optical-imaging agent approved by the FDA for use in glioma surgery and identification of tumor tissue.4 A multicenter randomized, controlled trial revealed that 5-ALA fluorescence-guided surgery (FGS) almost doubled the extent of tumor resection and also improved 6-month PFS.5 In this review, we will highlight the current evidence for use of 5-ALA FGS in brain tumor surgery, as well as discuss the future directions for its use.

Thoracic ultrasound competence for ultrasound guided pleural procedures: The creation and validation of an assessment tool for use in the certification of basic thoracic ultrasound competence

OBJECTIVES

Focused thoracic ultrasound (TUS) provides an increased safety profile when undertaking invasive pleural procedures. This has led to the requirement for defined curricula, high quality teaching and robust, validated assessment tools among physicians to ensure patient safety and clinical excellence. Current UK practice is based almost exclusively on expert consensus, but assessment methods employed have been shown to have low reliability and validity and are potentially open to bias. As a result, several assessment tools have been developed, although each has its own limitations.

METHODS

This study aimed to develop and validate an assessment tool corresponding to those skills associated with the most basic level of practice, defined recently as an emergency level operator in the British Thoracic Society Training Standards for Thoracic Ultrasound.

RESULTS

A total of 27 candidates were enrolled by two examiners based in Belfast and Oxford over a 10-month period between February and November 2019. Mean score of the inexperienced group was 44.3 (95% CI 39.2-49.4, range 28-54) compared with 74.9 (95% CI 72.8-77, range 64-80) in the experienced group providing an estimated mean difference of 30.7 between the two groups (95% CI 24.7-36.7; p < .001).

CONCLUSIONS

This tool appears to discriminate between trainees with limited experience of TUS performance and those with no experience. It has the potential to form part of the assessment strategy for trainees in the United Kingdom and beyond, alongside well established assessment tools in postgraduate training.

Critical analysis of the utility of initial pleural aspiration in the diagnosis and management of suspected malignant pleural effusion

INTRODUCTION

Current guidelines recommend an initial pleural aspiration in the investigation and management of suspected malignant pleural effusions (MPEs) with the aim of establishing a diagnosis, identifying non-expansile lung (NEL) and, at times, providing a therapeutic procedure. A wealth of research has been published since the guidelines suggesting that results and outcomes from an aspiration may not always provide sufficient information to guide management. It is important to establish the validity of these findings in a 'real world' population.

METHODS

A retrospective analysis was conducted of all patients who underwent pleural fluid (PF) sampling, in a single centre, over 3 years to determine the utility of the initial aspiration.

RESULTS

A diagnosis of MPE was confirmed in 230/998 (23%) cases, a further 95/998 (9.5%) were presumed to represent MPE. Transudative biochemistry was found in 3% of cases of confirmed MPE. Positive PF cytology was only sufficient to guide management in 45/140 (32%) cases. Evidence of pleural thickening on CT was associated with both negative cytology (χ² 1df=26.27, p<0.001) and insufficient samples (χ² 1df=10.39, p=0.001). In NEL 44.4% of patients did not require further procedures after pleurodesis compared with 72.7% of those with expansile lung (χ² 1df=5.49, p=0.019). In patients who required a combined diagnostic and therapeutic aspiration 106/113 (93.8%) required further pleural procedures.

CONCLUSIONS

An initial pleural aspiration does not achieve either definitive diagnosis or therapy in the majority of patients. A new pathway prioritising symptom management while reducing procedures should be considered.

A multicenter observational study of cs-131 seeds embedded in a collagen carrier tile in intracranial brain neoplasms: Trial in progress

TPS2073

Background: Brachytherapy is an efficacious means for radiation delivery in the treatment of a spectrum of central nervous system tumors. Traditional brachytherapy methods have been limited by uneven dose distribution, complicated workflow, extended procedural times, the cost of dedicated equipment, and frequent adverse events. To address these issues, a permanently implanted device with Cs-131 radiation seeds embedded in a bioresorbable collagen carrier tile (GammaTile [GT], GT Medical Technologies, Tempe, AZ USA) was developed. Described as surgically targeted radiation therapy (STaRT) to distinguish it from external beam radiation therapy, the device is FDA-cleared for use in newly diagnosed malignant intracranial neoplasms and recurrent intracranial tumors, and has demonstrated excellent safety and local control outcomes in early commercial use. Methods: The overarching primary objectives of this multicenter, prospective, observational (phase IV) registry study are to evaluate “real-world” clinical outcomes and patient reported outcomes that measure the safety and efficacy of STaRT using the GT device. The registry is planned for 600 prospectively enrolled subjects at up to 50 enrolling sites. All adult patients undergoing surgical resection of brain tumors of any pathology with intra-operative GT placement are eligible for enrollment, upon consent. Information on patient demographics, tumor pathology, overall survival, adverse events related to radiation or surgery, and quality of life (FACT-Br and LASA) will be collected. Serial MRIs will be collected, and timing of surgical bed recurrence and/or distant recurrence will be collected. Data will be collected at 1-, 3-, 6-, 9-, 12-, 18-, and 24-months, then every 6 months through 5 years. Results will be used to benchmark clinical outcomes of GT therapy, allow for comparisons to other existing treatments, and facilitate the design of future clinical trials. Enrollment opened on November 15, 2020, and seven subjects have been enrolled to date at three centers. This study will be the first observational study of resection plus STaRT, delivered by Cs-131 sources in permanently implanted bioresorbable collagen tile carriers, and will allow for evaluation of this treatment approach in a real world setting, as well as provide an information platform for cross-comparison of results obtained from ongoing GT clinical trials. Clinical trial information: NCT04427384.

Intercostal vessel screening prior to pleural interventions by the respiratory physician: a prospective study of real world practice

INTRODUCTION

The rising incidence of pleural disease is seeing an international growth of pleural services, with physicians performing an ever-increasing volume of pleural interventions. These are frequently conducted at sites without immediate access to thoracic surgery or interventional radiology and serious complications such as pleural bleeding are likely to be under-reported.

AIM

To assess whether intercostal vessel screening can be performed by respiratory physicians at the time of pleural intervention, as an additional step that could potentially enhance safe practice.

METHODS

This was a prospective, observational study of 596 ultrasound-guided pleural procedures conducted by respiratory physicians and trainees in a tertiary centre. Operators did not have additional formal radiology training. Intercostal vessel screening was performed using a low frequency probe and the colour Doppler feature.

RESULTS

The intercostal vessels were screened in 95% of procedures and the intercostal artery (ICA) was successfully identified in 53% of cases. Screening resulted in an overall site alteration rate of 16% in all procedures, which increased to 30% when the ICA was successfully identified. This resulted in procedure abandonment in 2% of cases due to absence of a suitable entry site. Intercostal vessel screening was shown to be of particular value in the context of image-guided pleural biopsy.

CONCLUSION

Intercostal vessel screening is a simple and potentially important additional step that can be performed by respiratory physicians at the time of pleural intervention without advanced ultrasound expertise. Whether the widespread use of this technique can improve safety requires further evaluation in a multi-centre setting with a robust prospective study.

Thoracic ultrasound competence for ultrasound-guided pleural procedures

Focused thoracic ultrasound has become essential in the guidance and direction of pleural interventions to reduce unwanted complications and as a result now forms a crucial component of physician training. Current training standards along with assessment methods vary widely, and are often not robust enough to ensure adequate competence.This review assesses the current state of training and assessment of thoracic ultrasound competence in various settings, allowing comparison with alternative competency based programmes. Future directions for training and assessment of thoracic ultrasound competence are discussed.

The microbiology of pleural infection in adults: a systematic review

BACKGROUND AND OBJECTIVES

Pleural infection is a major cause of morbidity and mortality among adults. Identification of the offending organism is key to appropriate antimicrobial therapy. It is not known whether the microbiological pattern of pleural infection is variable temporally or geographically. This systematic review aimed to investigate available literature to understand the worldwide pattern of microbiology and the factors that might affect such pattern.

DATA SOURCES AND ELIGIBILITY CRITERIA

Ovid MEDLINE and Embase were searched between 2000 and 2018 for publications that reported on the microbiology of pleural infection in adults. Both observational and interventional studies were included. Studies were excluded if the main focus of the report was paediatric population, tuberculous empyema or post-operative empyema.

STUDY APPRAISAL AND SYNTHESIS METHODS

Studies of ≥20 patients with clear reporting of microbial isolates were included. The numbers of isolates of each specific organism/group were collated from the included studies. Besides the overall presentation of data, subgroup analyses by geographical distribution, infection setting (community versus hospital) and time of the report were performed.

RESULTS

From 20 980 reports returned by the initial search, 75 articles reporting on 10 241 patients were included in the data synthesis. The most common organism reported worldwide was Staphylococcus aureus. Geographically, pneumococci and viridans streptococci were the most commonly reported isolates from tropical and temperate regions, respectively. The microbiological pattern was considerably different between community- and hospital-acquired infections, where more Gram-negative and drug-resistant isolates were reported in the hospital-acquired infections. The main limitations of this systematic review were the heterogeneity in the method of reporting of certain bacteria and the predominance of reports from Europe and South East Asia.

CONCLUSIONS

In pleural infection, the geographical location and the setting of infection have considerable bearing on the expected causative organisms. This should be reflected in the choice of empirical antimicrobial treatment.

A systematic review of comorbidities and outcomes of adult patients with pleural infection

Background

Pleural infection remains an important cause of mortality. This study aimed to investigate worldwide patterns of pre-existing comorbidities and clinical outcomes of patients with pleural infection.

Methods

Studies reporting on adults with pleural infection between 2000 and 2017 were identified from a search of Embase and MEDLINE. Articles reporting exclusively on tuberculous, fungal or post-pneumonectomy infection were excluded. Two reviewers assessed 20 980 records for eligibility.

Results

211 studies met the inclusion criteria. 134 articles (227 898 patients, mean age 52.8 years) reported comorbidity and/or outcome data. The majority of studies were retrospective observational cohorts (n=104, 78%) and the most common region of reporting was East Asia (n=33, 24%) followed by North America (n=27, 20%). 85 articles (50 756 patients) reported comorbidity. The median (interquartile range (IQR)) percentage prevalence of any comorbidity was 72% (58–83%), with respiratory illness (20%, 16–32%) and cardiac illness (19%, 15–27%) most commonly reported. 125 papers (192 298 patients) reported outcome data. The median (IQR) length of stay was 19 days (13–27 days) and median in-hospital or 30-day mortality was 4% (IQR 1–11%). In regions with high-income economies (n=100, 74%) patients were older (mean 56.5 versus 42.5 years, p<0.0001), but there were no significant differences in prevalence of pre-existing comorbidity nor in length of hospital stay or mortality.

Conclusion

Patients with pleural infection have high levels of comorbidity and long hospital stays. Most reported data are from high-income economy settings. Data from lower-income regions is needed to better understand regional trends and enable optimal resource provision going forward.

In pleural infection, patients from higher-income countries tend to be older with more comorbidities and are more likely to be referred for fibrinolytic treatment in comparison to patients from lower-income countrieshttp://bit.ly/2K2M5HL

Survival in patients with malignant pleural effusion undergoing talc pleurodesis

OBJECTIVES

Recent observations indicate a potential survival benefit in patients with malignant pleural effusion (MPE) who achieve successful pleurodesis in comparison to patients who experience effusion recurrence post pleurodesis. This study aimed to explore this observation using two datasets of patients with MPE undergoing talc pleurodesis.

MATERIALS AND METHODS

Dataset 1 comprised patients who underwent talc pleurodesis at Oxford Pleural Unit for MPE. Dataset 2 comprised patients enrolled in the TIME1 clinical trial. Pleurodesis success was defined as absence of need for further therapeutic procedures for MPE in the three months following pleurodesis. Data on various clinical, laboratory and radiological parameters were collected and survival was compared according to pleurodesis outcome (success vs. failure) after adjusting for the aforementioned parameters.

RESULTS

Dataset 1 comprised 60 patients with mean age 74.1±10.3 years. The most common primary malignancies were mesothelioma, breast and lung cancer. 29 patients (48.3%) achieved pleurodesis. The adjusted odds ratio (aOR) for poor survival with pleurodesis failure was 2.85 (95% CI 1.08-7.50, =p 0.034). Dataset 2 comprised 259 patients from the TIME1 trial. The mean age was 70.8±10.3 and the most common primary malignancies were mesothelioma, lung and breast cancer. Pleurodesis was successful in 205 patients (79%). aOR for poor survival was 1.62 (95% CI 1.09-2.39, p = 0.015).

CONCLUSION

Achieving pleurodesis seems to impart a survival benefit in patients with MPE. Further studies are required to explore factors that may contribute to this phenomenon and to address the difference in survival between pleurodesis and indwelling pleural catheter interventions.

Secondary pneumothorax in end-stage lung disease complicated by noninvasive ventilation and a persistent air leak

Pneumothorax is a well-recognised complication of end-stage COPD, but the management is often complex and may be complicated by other sequelae of advanced respiratory disease including the requirement for NIV http://ow.ly/vkoJ30mB4nZ.

Malignant Pleural Effusions: Management Options

Malignant pleural effusion (MPE) represents advanced metastatic malignancy and is associated with poor median survival. Incidence remains high and continues to rise, in part due to changing population demographics. This therefore represents a significant health care burden. Management is predominantly palliative in nature and multiple interventions are available within conventional treatment paradigms, all of which are proven to result in statistically significant patient benefit. This article further explores the methods available in the management of MPE along with the pitfalls, complications, and alternatives. Recent advances within the field are discussed with an exploration of likely future directions, including the role of ultrasound as a prospective predictor and the role of intrapleural fibrinolytic therapy.

A retrospective analysis comparing the use of ProCore® with standard fine needle aspiration in endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA)

Endobronchial ultrasound has become first line in the investigation of mediastinal lesions suspicious for malignancy in keeping with National Institute for Health and Care Excellence (NICE) guidelines; however, needle size and type required to maximise diagnostic sensitivity remains unclear. Previous meta-analyses have compared the use of ProCore with standard fine needle aspiration in the assessment of pancreatic masses with differences noted only in the number of passes required. We aim to assess whether a ProCore needle improves diagnostic sensitivity in EBUS-TBNA. Complete follow-up data regarding all 235 patients undergoing EBUS-TBNA in a district general hospital has been collected since the service's inception in 2012. Results were collated and retrospectively analysed allowing for calculation of test sensitivity and specificity. Comparison was then made between procedures where standard fine needle aspiration was performed and those using a ProCore needle. Overall sensitivity of EBUS-TBNA was shown to be 85% with a specificity of 100% in keeping with quoted figures from other centres. Standard fine needle aspiration produced a sensitivity of 77% (85/110) versus ProCore sensitivity of 92% (115/125) with a p value of 0.0016. Thirty percent (33/110) of patients undergoing standard fine needle aspiration required an appropriate crossover technique such as mediastinoscopy or CT-guided FNA in order to either obtain or confirm the diagnosis compared with 15% (19/125) of the ProCore group with a p value of 0.0064. Our retrospective analysis shows a statistically significant difference in the diagnostic sensitivity of sampling mediastinal lymphadenopathy using a ProCore needle compared with standard fine needle aspiration. It also shows that a significantly fewer number of patients required further procedures in order to obtain or confirm the diagnosis. This could potentially be confounded by the retrospective nature of the study design; however, due to the statistical significance demonstrated, further study is required.

Abstract TMP25: Rates Of Complications And Aneurysm Occlusion In Patients Undergoing Treatment Of Cerebral Aneurysms Utilizing Flow Diversion With The Pipeline Embolization Device And Algorithm Adjusted Antiplatelet Therapy

Introduction: The need for therapeutic dual antiplatelet therapy in patients with cerebral aneurysms treated with flow-diverting stents increases the risk of thromboembolic and hemorrhagic complications. To balance these risks, we assessed patients for their responsiveness to dual antiplatelet therapy using a modified platelet aggregation study (PIPA). We hypothesized that double doses of clopidogrel or aspirin in patients with antiplatelet non-responsiveness would reduce the incidence of thromboembolic complications without increasing the incidence of hemorrhage or decreasing the rate of aneurysm occlusion.

Methods: 79 patients with 98 cerebral aneurysms were treated with the pipeline embolization device. All patients with a suboptimal PIPA received double doses of clopidogrel or aspirin prior to treatment. Aneurysm occlusion was categorized using the Roy-Raymond Occlusion Classification (RROC). Chi-square or Fisher’s exact tests were used for univariate analyses, and logistic regression was used to identify potential predictors of complications and aneurysm occlusion.

Results: Seven patients had a major complication and 7 had a minor complication (8.9%). There were 3 cerebral ischemic strokes (3.8%) and 5 cerebral hemorrhages (6.3%). Thirty-eight patients had angiographic follow-up at 6 months. Of these, 18 patients were resistant to clopidogrel or aspirin, and 19 received double dose therapy prior to treatment. Double dose clopidogrel or aspirin was not associated with major, minor, cerebral ischemic or hemorrhagic complications. Twenty-one patients (55.3%) had complete occlusion of their aneurysms (RROC type 1), and 17 patients were categorized as RROC type 2 or 3 at 6 months. Treatment with double dose clopidogrel or aspirin was not associated with reduced occlusion (RROC type 2 or 3) in a univariate and multivariate analysis.

Conclusions: In patients treated with flow-diverting stents, the risk of ischemia must be balanced with the risk of hemorrhage. We found that the use of double dose clopidogrel and aspirin in the setting of antiplatelet non-responsiveness is safe. It is not associated with increased hemorrhagic complications. Patients treated with double dose therapy did not exhibit a reduced aneurysm occlusion rate.