Steven C. Leong

Guidelines for the diagnosis and treatment of malignant pleural mesothelioma

Malignant Pleural Mesothelioma (MPM), the asbestos-induced neoplasm originating in the mesothelial lining of the lung cavities represents significant diagnostic and therapeutic challenges for clinicians in Australia. Very seldom diagnosed prior to the advent of widespread asbestos mining in the early to midtwentieth century, it has sharply risen in incidence over the last five decades. According to the most recent Australian Institute of Health and Welfare data, there were 666 cases of malignant mesothelioma diagnosed in Australia in 2009 and around 90% of them originated in the pleura.

Electromagnetic navigation bronchoscopy: A descriptive analysis

Electromagnetic navigation bronchoscopy (ENB) is an exciting new bronchoscopic technique that promises accurate navigation to peripheral pulmonary target lesions, using technology similar to a car global positioning system (GPS) unit. Potential uses for ENB include biopsy of peripheral lung lesions, pleural dye marking of nodules for surgical wedge resection, placement of fiducial markers for stereotactic radiotherapy, and therapeutic insertion of brachytherapy catheters into malignant tissue. This article will describe the ENB procedure, review the published literature, compare ENB to existing biopsy techniques, and outline the challenges for widespread implementation of this new technology.

The science behind the 7th edition Tumour, Node, Metastasis staging system for lung cancer.

The Tumour, Node, Metastasis (TNM) system for classifying lung cancer is the cornerstone of modern lung cancer treatment and underpins comparative research; yet is continuously evolving through updated revisions. The recently published Union for International Cancer Control 7th Edition TNM Classification for lung cancer addresses many of its predecessors shortcomings and has been subject to rigorous evidence‐based methodology. It is based on a retrospective analysis of over 80 000 lung cancer patients treated between 1990 and 2000 carried out by the International Association for the Study of Lung Cancer. The dataset was truly international and included patients treated by all modalities. Extensive internal and external validation of the findings has ensured that the recommendations are robust and generalizable. For the first time, a single classification system has been shown to be applicable not only to non‐small cell lung cancer, but also to be of prognostic significance in small cell lung cancer and bronchopulmonary carcinoid tumours.

Mediastinal abscess after endobronchial ultrasound-guided transbronchial needle aspiration: a case report and literature review.

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive technique that allows lung cancer nodal staging and biopsy of parabronchial and paratracheal tissue. Its simplicity, high diagnostic yield, ability to diagnose both benign and malignant conditions, and exceedingly low complication rate has resulted in rapid widespread adoption by surgeons and physicians. EBUS-TBNA–related complications, however, do occur and need to be considered when assessing the risk-benefit profile of performing the procedure, and if the patient represents with unexpected symptoms after the procedure. We describe a 64-year-old woman who presented with a mediastinal abscess 5 days after EBUS-TBNA. This case demonstrates the importance of considering EBUS-TBNA–related complications to guide relevant imaging decisions and antibiotic choices. We review the published literature regarding infective complications of EBUS-TBNA and propose possible pathophysiologies. These complications are likely to increase in frequency as the technique is more widely adopted.

Screen-detected subsolid pulmonary nodules: long-term follow-up and application of the PanCan lung cancer risk prediction model

OBJECTIVE To report the long-term follow-up of subsolid nodules (SSNs) detected in participants of a prospective low-dose CT lung cancer screening cohort, and to investigate the utility of the PanCan model in stratifying risk in baseline SSNs. METHODS Participants underwent a baseline scan, two annual incidence scans and further follow-up scans for the detected nodules. All SSNs underwent a minimum of 2 years of follow-up (unless resolved or resected). Risk of malignancy was estimated using the PanCan model; discrimination [area under the receiver-operating characteristic curve (AUC)] and calibration (Hosmer-Lemeshow goodness-of-fit test) were assessed. The Mann-Whitney U-Wilcoxon test was used to compare estimated risk between groups. RESULTS 70 SSNs were detected in 41 (16.0%) out of 256 total participants. Median follow-up period was 25.5 months (range 2.0-74.0 months). 29 (41.4%) SSNs were transient. Five (7.1%) SSNs were resected, all found to be Stage I lung adenocarcinoma, including one SSN stable in size for 3.0 years before growth was detected. The PanCan model had good discrimination for the 52 baseline SSNs (AUC = 0.89; 95% confidence interval 0.76-1); the Hosmer-Lemeshow goodness-of-fit test was non-significant (p = 0.27). Estimated risk was significantly higher in the baseline SSNs found to be cancer vs those not found to be cancer after 2-6 years of follow-up (p < 0.01). CONCLUSION Our findings support a long-term follow-up approach for screen-detected SSNs for 3 years or longer. The PanCan model appeared discriminatory and well calibrated in this cohort. ADVANCES IN KNOWLEDGE The PanCan model may have utility in identifying low-risk SSNs which could be followed with less frequent CT scans.

Lung cancer screening feasibility in Australia

The National Lung Screening Trial (NLST) reported a 20% relative reduction in lung cancer-specific mortality using low-dose computed tomography (LDCT) screening [1]. US Preventative Services Task Force modelling [2] illustrates the potentially large benefits of screening, yet nationwide population-based screening has not been adopted. Controversial issues include high false positivity, and uncertain cost-effectiveness and relative applicability to different settings and countries [3–6]. The Queensland Lung Cancer Screening Study (QLCSS) is the first study to assess NLST screening protocol feasibility in Australia. Low-dose CT screening using the NLST protocol appears feasible in the Australian health setting http://ow.ly/JwtU2

Is Digital Tomosynthesis on Par With Computed Tomography for the Detection and Measurement of Pulmonary Nodules

Chest digital tomosynthesis (DT) has potential advantages compared to computed tomography (CT) such as radiation dose reduction. However, the role of DT in pulmonary nodule management remains investigative. We compared DT against CT for pulmonary nodule detection and size measurement. A clinical population comprising 54 nodules from 30 patients and a screening population comprising 42 nodules from 52 patients were included. Scans were independently read by two radiologists. Agreement in nodule measurements between readers and between modalities was assessed by Bland-Altman analysis using a 95% level of significance. The DT true positive fraction for the two readers was 0.44 and 0.39 in the clinical population, and 0.10 and 0.05 in the screening population. No significant inter-modality bias was observed between DT and CT measurements of nodule size, but the range of variation between modalities was approximately 30%. Inter-reader DT measurements also showed no significant bias, with a range of variation of approximately 15%. We conclude that DT has poor nodule detection sensitivity compared to CT. However, DT showed good measurement reproducibility and may be useful for monitoring growth of existing pulmonary nodules.

Endobronchial Silicosis and Tuberculosis Presenting as the Right Middle Lobe Syndrome.

radiopaque cuff of the RP-EBUS guide sheath can get dislodged. In both cases reported here, the radiopaque cuff was retrieved. However, its retention could lead to a foreign body reaction, airway obstruction, and infection. Careful instrument manipulation, use of fluoroscopy with magnification for visualization of sampling tools’ functioning, and modification of the sheath might prevent this complication. Careful instrument manipulation, use of fluoroscopy with magnification for visualization of sampling tools’ functioning, and modification of the sheath might prevent this complication. A more resistant sheath with preserved low friction and manoeuvrability is desirable, and making the sheath inherently radiopaque would obviate the need for a distal cuff.

Electromagnetic navigation bronchoscopy for the diagnosis of Aspergillus infection.

Electromagnetic navigation bronchoscopy (ENB) is a new diagnostic tool for the evaluation of pulmonary lesions inaccessible by conventional bronchoscopy. Most often, ENB is used for the diagnosis of lung cancer, but can be used to evaluate fungal conditions and other diseases. We present the case of a 44‐year‐old woman who was diagnosed with Aspergillus via ENB.

The Queensland Lung Cancer Screening Study: enhanced population risk stratification increases effectiveness of low dose CT screening for lung cancer

Background : The current guidelines for acceptable levels of ambient PM ( Methods : The PM fraction was extracted from surface soil samples from 4 communities across Western Australia. BALB/c 10 mice were intranasally exposed to 100 µg of PM . Control mice received 100 µg of polystyrene beads (2.5 µm) or vehicle 10 alone. Mice were assessed for inflammation (cellular influx, MIP-2, IL-6 and IL-1β), lung volume (plethysmography) and lung mechanics (forced oscillation technique) 6, 24 or 168 hours post-exposure. The physical and chemical characteristics of the particles were assessed by cascade impactor and ICP-MS/OES respectively. Principal component analysis of the outcome measures were used to construct lung impairment scores. Multivariate linear regression models were then used to identify the characteristics of the particles driving the lung responses. Results : Exposure to geogenic particles caused an acute inflammatory response (6 hours post-exposure), an acute impairment in lung mechanics (24 hours post-exposure) and a long term deficit in lung volume (168 hours post-exposure). Both the inflammatory response and long term deficits in lung volume were associated with the concentration of Fe and variability in particle size (GSD) while the impairment in lung mechanics was associated with Fe and particle size (MMAD). Conclusions : Despite the complex physico-chemical characteristics of geogenic dusts we were able to identify the concentration of Fe and physical dimensions of the particles as the key drivers of lung responses. Using these data we may be able to predict which communities are at greatest risk of adverse respiratory health due to high geogenic particle loads.