Apparent diffusion coefficient benchmarking and inter-scanner variability; preparing for biological image guided...

Area of Science:

• Radiotherapy
• Quantitative MRI
• Biomarker validation

Background:

• Biological Image Guided Adaptive Radiotherapy Treatments (BIGART) require quantitative imaging biomarkers (qMRI).
• Apparent diffusion coefficient (ADC) is a key qMRI biomarker derived from diffusion-weighted imaging (DWI).
• Evaluating MRI scanner performance for ADC is essential for BIGART implementation.

Purpose of the Study:

• To assess MRI scanner performance in measuring ADC values.
• To compare measured ADC values with established reference data.
• To validate MRI scanners for use in future BIGART protocols.

Main Methods:

• Two Siemens SOLA 1.5T MRI scanners were used.
• A CaliberMRI phantom and QIBA protocol were employed for data acquisition.
• QCAL-MR® software platform was utilized for data analysis.

Main Results:

• ADC measurements showed a mean deviation <4% from NIST-certified values.
• Inter-scanner variability was low, within 3.6%.
• ADC values aligned with the QIBA brain profile, confirming measurement reliability.

Conclusions:

• MRI scanner performance can be effectively benchmarked using qMRI data like ADC.
• The validated ADC measurements provide confidence in detecting true changes in brain lesions (≥11% with 95% confidence).
• This study supports the development of multicenter BIGART trials using ADC for personalized radiotherapy in brain tumors.