Quantitative Comparison of SPECT and PET Performance for Clinical Theranostic Applications.

Area of Science:

• Nuclear medicine
• Medical imaging
• Radiopharmaceutical therapy

Background:

• Radiopharmaceutical therapy is an emerging treatment for metastatic disease, enabling personalized care via imaging.
• Quantitative imaging is growing in importance, necessitating systematic assessment of radionuclides and scanner performance.
• Standardized evaluation of SPECT and PET is needed to compare their effectiveness in targeted radiotherapy imaging.

Purpose of the Study:

• To quantitatively and qualitatively compare SPECT and PET performance.
• To assess effectiveness in imaging applications for targeted radiotherapy.
• To evaluate imageable radionuclides and scanner performance under comparable conditions.

Main Methods:

• Used the National Electrical Manufacturers Association International Electrotechnical Commission body phantom.
• Assessed recovery coefficients, contrast, spatial resolution, and noise.
• Evaluated SPECT with 99mTc, 203Pb, and 177Lu; PET with 18F, 89Zr, and 64Cu.

Main Results:

• PET showed superior spatial resolution and activity recovery compared to SPECT.
• SPECT was limited by lower sensitivity, photon scatter, and collimator design.
• For PET, 18F demonstrated high quantitative accuracy; 89Zr and 64Cu performed similarly. For SPECT, 99mTc outperformed 203Pb and 177Lu.

Conclusions:

• Appropriate selection of imaging modalities, isotopes, and reconstruction parameters is vital for theranostic applications.
• Limitations in quantitative accuracy must be addressed for precise treatment strategies.
• 203Pb is a suitable diagnostic partner for 212Pb, and quantitative methods validate PET/SPECT evaluation.