Advancing Rapid Acquisition in Lung PET-CT: Protocol Optimisation via Reduced ¹⁸F-FDG Activity and Scan Duration

Area of Science:

• Nuclear Medicine
• Oncology
• Radiology

Background:

• Lung cancer (LC) is a significant health concern globally, with diagnosis and staging heavily reliant on ¹⁸F-FDG PET-CT.
• Current PET-CT protocols may be optimized for efficiency and patient safety without compromising diagnostic accuracy.

Purpose of the Study:

• To evaluate the impact of reduced acquisition durations on the diagnostic performance of half-dose ¹⁸F-FDG PET-CT in lung cancer patients.
• To determine the optimal scan duration for balancing efficiency, safety, and diagnostic quality.

Main Methods:

• Prospective enrollment of 30 newly diagnosed lung cancer patients.
• Administration of a 50% dose of ¹⁸F-FDG (1.85 MBq/kg) followed by PET-CT imaging.
• Retrospective reconstruction of datasets acquired at 50, 66, and 120 seconds per bed position (s/bp) to assess lesion contrast ratios (TLR, TSR, TBR).

Main Results:

• ¹⁸F-FDG PET-CT scans with reduced acquisition times (66 s/bp) maintained stable SUV_max values for lung cancer lesions.
• Longer acquisition durations (66 and 120 s/bp) improved tumour contrast ratios (TLR, TSR, TBR), enhancing diagnostic confidence.
• Tumour-to-background ratio (TBR) demonstrated high reliability and near-perfect agreement across acquisition durations, serving as a robust indicator.

Conclusions:

• Shortened half-dose ¹⁸F-FDG PET-CT acquisitions are feasible for lung cancer staging.
• A 66 s/bp protocol at a reduced ¹⁸F-FDG dose offers an optimal balance between scan efficiency, patient safety, and diagnostic performance.
• This optimized protocol is suitable for routine clinical oncology practice, particularly for patients requiring frequent imaging.