Generating harmonized SUV within the EANM EARL accreditation program: software approach versus EARL-compliant...

Area of Science:

• Nuclear Medicine
• Medical Imaging
• Oncology

Background:

• Advanced PET scanner technology, including point spread function (PSF) reconstruction, enhances diagnostic performance but introduces device and reconstruction-dependent variations in standardized uptake values (SUVs).
• These SUV variations hinder multicenter studies and the use of SUVs as prognostic biomarkers or early treatment response indicators in oncology.
• This study investigates two SUV harmonization strategies to ensure data comparability across different PET systems.

Purpose of the Study:

• To compare two SUV harmonization strategies for positron emission tomography (PET) data.
• To evaluate the effectiveness of using a second reconstruction compliant with harmonization standards versus a proprietary software tool (EQ.PET).
• To maintain comparability with older PET systems while utilizing newer reconstruction algorithms for improved lesion detection.

Main Methods:

• PET data from 50 non-small cell lung cancer patients were analyzed.
• Data underwent PSF reconstruction for optimal tumor detection and ordered subset expectation maximization (OSEM3D) reconstruction to simulate older PET systems.
• Two harmonization methods were applied: (1) PSF reconstruction with a 7 mm Gaussian filter (PSF7) and (2) application of the EQ filter post-reconstruction (PSF_EQ).
• SUV values (SUVmax, SUVpeak) were compared using regression analyses and Bland-Altman plots.

Main Results:

• Analysis included 171 lesions (lung lesions, lymph nodes, metastases).
• Mean SUVmax and SUVpeak ratios between PSF7/OSEM3D and PSF_EQ/OSEM3D reconstructions were close to 1, indicating good agreement.
• Comparison between PSF7 and PSF_EQ showed minimal differences in SUVmax and SUVpeak, with ratios near 1.

Conclusions:

• SUV variations due to reconstruction differences can be overcome by employing harmonization strategies.
• Both evaluated methods (dual reconstruction and EQ.PET software) achieve harmonized quantification, with EQ.PET offering time savings in reconstruction and interpretation.
• Manufacturers are encouraged to adopt similar solutions or develop vendor-neutral harmonization approaches for broader clinical utility.