Significant dose reduction is feasible in FDG PET/CT protocols without compromising diagnostic quality

Area of Science:

• Nuclear Medicine
• Radiology
• Medical Imaging

Background:

• Positron Emission Tomography/Computed Tomography (PET/CT) is crucial in oncology.
• Optimizing radiation dose in PET/CT is essential for patient safety.
• Fluorodeoxyglucose (FDG) is a common radiotracer used in oncological PET/CT.

Purpose of the Study:

• To reduce radiation dose for patients undergoing oncological FDG PET/CT scans.
• To optimize existing PET/CT protocols for lower radiation exposure.
• To evaluate the impact of dose reduction on image quality and diagnostic interpretability.

Main Methods:

• Retrospective evaluation of 322 patients scanned with varying FDG activities and CT current-time products.
• Calculation of effective radiation dose for each protocol.
• Subjective image quality assessment (IQ score) by referring physicians.
• Quantitative image quality evaluation through liver noise measurement.

Main Results:

• Achieved a mean overall radiation dose reduction of 28.7% (CT: 34.9%, PET: 23.4%).
• Observed significant degradation in subjective IQ scores and quantitative noise levels.
• No increase in the number of non-interpretable studies (IQ score >2) for CT.
• All reduced-activity PET images remained interpretable (IQ score ≤3).

Conclusions:

• Optimized oncological FDG PET/CT protocols successfully reduced patient radiation dose.
• A slight decrease in image quality was noted but did not compromise diagnostic interpretability.
• The new protocol regime was implemented effectively, maintaining clinical confidence in diagnostic accuracy.