Body Weight-Based Protocols During Whole Body FDG PET/CT Significantly Reduces Radiation Dose without Compromising Image Quality:Findings in a Large Cohort Study

Abstract

Rationale and objectives: To investigate radiation dose reduction during whole body fluorodeoxyglucose (¹⁸F-FDG) positron emission tomographic (PET)/computed tomography (CT) by employing weight-based protocols.

Materials and methods: One thousand and twenty-eight patients were referred for ¹⁸F-FDG PET/CT study with one of two protocols: conventional protocol I; 120 kVp, 120 mAs, 0.5 second rotation time, pitch 0.8 mm/rot across all body weights; four-tier body weight protocol II all used 140 kVp, 0.75 seconds rotation time and pitch 0.8 mm/rot: Protocol A (≤60 kg): 35 mAs, Protocol B (61-80 kg): 50 mAs, Protocol C (81-100 kg): 65 mAs, and Protocol D: (>101 kg): 100 mAs. All protocols employed tube current modulation. Quantitative and qualitative image visual grading characteristics assessed image quality.

Results: Patient demographics demonstrated no significant difference between each protocol except for patient weight in weight protocol IIB (p < 0.009). Mean effective dose in all protocols were significantly lower in Protocol B compared to A (p < 0.009). Contrast-to-noise ratio demonstrated no differences between each protocol (p < 0.21) except for weight protocol in protocol IIA (<60 kg, p = 0.035) with the visual grading characteristics demonstrating preference over protocol II compared to I.

Conclusion: Significant reduction in radiation dose can be achieved using patient-specific body weight-based protocols during whole-body ¹⁸F-FDG PET/CT without compromising image quality when employing weight-based protocols.