Smart scanning for two: [¹⁸F]FDG dose optimization for pregnant patients using LAFOV PET/CT technology

Area of Science:

• Nuclear Medicine
• Radiology
• Medical Imaging

Background:

• Positron emission tomography/computed tomography (PET/CT) is crucial for diagnosing various conditions.
• Optimizing radiation dose in pregnant patients undergoing PET/CT is essential to minimize fetal exposure.
• Current dosage protocols may not adequately account for body composition variations in pregnancy.

Purpose of the Study:

• To assess the relationship between image quality and radiation dose in pregnant patients undergoing [¹⁸F]FDG PET/CT.
• To identify the most effective body composition metric for predicting image quality.
• To develop a pregnancy-tailored dosage model for [¹⁸F]FDG PET/CT.

Main Methods:

• Retrospective analysis of [¹⁸F]FDG PET/CT scans in pregnant patients.
• Reconstruction of images with varying quality using raw PET data.
• Assessment of image quality via signal-to-noise ratio (SNR) in the liver and Likert scores.
• Modeling minimum scan statistics based on SNR and body composition metrics (weight, weight-to-height ratio, BMI, BSA).
• Estimation of fetal radiation dose using PET conversion factors and CTDIvol.

Main Results:

• Eleven patients were included in the analysis.
• A strong correlation was observed between SNR and Likert scores (R² = 0.80), with an SNR of 10.72 indicating acceptable image quality.
• Body surface area (BSA) was the strongest predictor of image quality (R² = 0.85), outperforming other metrics.
• The proposed dosage model achieved activity reductions of 41-96% compared to existing protocols.
• Estimated fetal radiation doses were 0.066 mGy for PET and 0.31 mGy for CT.

Conclusions:

• BSA is a reliable predictor of [¹⁸F]FDG PET/CT image quality in pregnant individuals.
• The developed dosage regimen significantly reduces radiation exposure.
• This model provides a foundation for establishing specific PET/CT dosage protocols for pregnancy.