Imaging of Thoracic Cavity Tumors

Unresectable stage III non-small cell lung cancer: Insights from a Portuguese expert panel

INTRODUCTION

The management of unresectable stage III non-small cell lung cancer (NSCLC) is clinically challenging and there is no current consensus on optimal strategies. Herein, a panel of Portuguese experts aims to present practical recommendations for the global management of unresectable stage III NSCLC patients.

METHODS

A group of Portuguese lung cancer experts debated aspects related to the diagnosis, staging and treatment of unresectable stage III NSCLC in light of current evidence. Recent breakthroughs in immunotherapy as part of a standard therapeutic approach were also discussed. This review exposes the major conclusions obtained.

RESULTS

Practical recommendations for the management of unresectable stage III NSCLC were proposed, aiming to improve the pathways of diagnosis and treatment in the Portuguese healthcare system. Clinical heterogeneity of patients with stage III NSCLC hinders the development of single standardised algorithm where all fit.

CONCLUSIONS

A timely diagnosis and a proper staging contribute to the best management of each patient, optimizing treatment tolerance and effectiveness. The expert panel considered chemoradiotherapy as the preferable approach when surgery is not possible. Management of adverse events and immunotherapy as a consolidation therapy are also essential steps for a successful strategy.

Robotic-assisted computed tomography-guided 18F-FDG PET/computed tomography-directed biopsy for diagnosis of intra thoracic lesions: An experience from a tertiary care centre in North India

OBJECTIVE

The aim of this study was to assess the diagnostic yield of robotic-assisted computed tomography (CT)-guided F-FDG PET/CT-directed biopsy for the evaluation of intrathoracic space occupying lesions.

METHODS

Twenty-four patients being evaluated for intrathoracic masses were included in the study. The indications were patients with unknown/likely primary detected from PET-CT, suspicious lesions identified from PET-CT in a known primary disease and fine needle aspiration cytology/CT-guided biopsy negative lesions with a high index of suspicion for malignancy. Biopsies were carried out with the help of automated radiology arm (ROBIO-EX) which is essentially a needle positioning and holding device. A two-day protocol was followed in which PET-CT scan was done on the first day, biopsy procedure was done on the next scheduled day. PET images were refused with the CT images done on the second day in the console by using manual alignment and then a biopsy was carried out with the help of a robotic arm. Primary outcome was histopathological yield from the obtained specimens.

RESULTS

Tissue yield was 100% (n = 24) and histopathological diagnosis rate was 96% (n = 23). Out of the 24 lesions biopsied 30% (n = 8) were benign and 70% (n = 16) turned out to be malignant. The complication rates were pneumothorax 4% (n = 1) and haemothorax 4% (n = 1).

CONCLUSION

Robotic-assisted CT-guided F-FDG PET/CT-directed biopsy is a useful and accurate technique for diagnostic evaluation of intrathoracic neoplasms with minimal complications rates as compared with conventional imaging techniques.

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.

Real-time intraprocedural 18F-FDG PET/CT-guided biopsy using automated robopsy arm (ARA) in the diagnostic evaluation of thoracic lesions with prior inconclusive biopsy results: initial experience from a tertiary health care centre

OBJECTIVE

The aim of this study was to assess the feasibility and appraise the diagnostic utility of real time ¹⁸F-FDG PET/CT-guided biopsy under automated robopsy arm (ARA) guidance for the evaluation of thoracic lesions with prior inconclusive biopsy results.

METHODS

PET/CT-guided biopsy of thoracic lesions was performed in patients who had at least one previous inconclusive biopsy. A total of 25 patients (male:female-18 males, 7 females; age: range, 13-75; mean, 53.7) were included in this study. All these patients underwent percutaneous needle biopsies under real-time PET/CT guidance using ARA (ROBIO-EX, Perfint healthcare Pvt Ltd, Chennai, India) needle navigation technique. Histopathology and clinical follow-up results were reviewed for assessing the accuracy of procedures.

RESULTS

Adequate representative tissue sample could be retrieved in all the patients. No major procedure-related complications were encountered in any patient. Of the 25 procedures, 21 lesions were positive for malignancy and benign findings were observed in the other 4 lesions on histopathology. None of the patients required further biopsy in arriving at a final diagnosis. Overall diagnostic yield of the procedure was 100%.

CONCLUSION

Real time ¹⁸F-FDG PET/CT guidance for percutaneous biopsies of lung and mediastinal lesions is a feasible technique with potential utility in patients with previous inconclusive biopsy results. Advances in knowledge: ¹⁸F-FDG PET/CT guidance reduces the sampling errors by specifically targeting areas of viability and avoiding necrosis/atelectasis. A navigational tool like ARA is thought to help in accurately targeting these areas.

Diffusion Weighted Imaging Can Distinguish Benign from Malignant Mediastinal Tumors and Mass Lesions: Comparison with Positron Emission Tomography

BACKGROUND

Diffusion-weighted magnetic resonance imaging (DWI) makes it possible to detect malignant tumors based on the diffusion of water molecules. It is uncertain whether DWI is more useful than positron emission tomography-computed tomography (PET-CT) for distinguishing benign from malignant mediastinal tumors and mass lesions.

MATERIALS AND METHODS

Sixteen malignant mediastinal tumors (thymomas 7, thymic cancers 3, malignant lymphomas 3, malignant germ cell tumors 2, and thymic carcinoid 1) and 12 benign mediastinal tumors or mass lesions were assessed in this study. DWI and PET-CT were performed before biopsy or surgery.

RESULTS

The apparent diffusion coefficient (ADC) value (1.51±0.46x10(-3) mm2/sec) of malignant mediastinal tumors was significantly lower than that (2.96±0.86x10(-3) mm2/sec) of benign mediastinal tumors and mass lesions (P<0.0001). Maximum standardized uptake value (SUVmax) (11.30±11.22) of malignant mediastinal tumors was significantly higher than that (2.53±3.92) of benign mediastinal tumors and mass lesions (P=0.0159). Using the optimal cutoff value (OCV) 2.21x10(-3) mm2/sec for ADC and 2.93 for SUVmax, the sensitivity (100%) by DWI was not significantly higher than that (93.8%) by PET-CT for malignant mediastinal tumors. The specificity (83.3%) by DWI was not significantly higher than that (66.7%) for benign mediastinal tumors and mass lesions. The accuracy (92.9%) by DWI was not significantly higher than that (82.1%) by PET-CT for mediastinal tumors and mass lesions.

CONCLUSIONS

There was no significant difference between diagnostic capability of DWI and that of PET-CT for distinguishing mediastinal tumors and mass lesions. DWI is useful in distinguishing benign from malignant mediastinal tumors and mass lesions.