Can PET/CT be used more effectively in pleural effusion evaluation?

Area of Science:

• Nuclear Medicine
• Radiology
• Oncology

Background:

• Characterizing pleural effusion (PE) can be challenging, particularly for patients who cannot undergo invasive diagnostic procedures.
• ¹⁸F-FDG-PET/CT offers a non-invasive imaging modality that may aid in the diagnosis and management of PE.
• Reducing the need for invasive procedures can improve patient outcomes and healthcare efficiency.

Purpose of the Study:

• To evaluate the utility of ¹⁸F-FDG-PET/CT in reducing invasive procedures for pleural effusion diagnosis.
• To determine if specific ¹⁸F-FDG-PET/CT parameters can accurately characterize malignant pleural effusion (MPE).
• To assess the potential of ¹⁸F-FDG-PET/CT in facilitating clinical decision-making for patients with contraindications to invasive methods.

Main Methods:

• Retrospective analysis of 67 patients' data, including ¹⁸F-FDG-PET/CT scans, pleural fluid cytologies (PFCs), and pleural biopsies.
• Malignant PE was defined by positive cytology or biopsy.
• Benign PE was defined by two consecutive negative PFCs in patients without biopsy, or consensus with imaging and clinical parameters for those with one negative PFC.

Main Results:

• No single ¹⁸F-FDG-PET/CT parameter alone could characterize PE.
• Combining PE SUV_max > 1.3 or PE SUV_max/MBP SUV_mean > 1.2 with specific imaging findings (pleural thickness, atelectasis, lung nodules/masses, or multiple pulmonary nodules) yielded 100% specificity and PPV, and ~90% accuracy for MPE.
• All 29 patients with SUV_max > 1.3 and at least one additional parameter were diagnosed with MPE, though sensitivity and NPV remained insufficient.

Conclusions:

• ¹⁸F-FDG-PET/CT findings, when combined with specific criteria, can support the primary diagnosis of MPE in patients with contraindications to invasive procedures.
• Lower SUV_max values and the absence of specific imaging findings make a diagnosis of benign PE difficult to confirm solely based on these results.
• ¹⁸F-FDG-PET/CT can potentially reduce the number of invasive procedures required for PE characterization, especially in select patient groups.