Optimal theranostic SPECT imaging protocol for 223radium dichloride therapy

Area of Science:

• Nuclear Medicine
• Radiopharmaceutical Therapy
• Medical Imaging Physics

Background:

• Accurate patient dosimetry for radium-223 dichloride (²²³RaCl₂) theranostics relies on high-quality SPECT imaging.
• Image acquisition and reconstruction protocols significantly impact quantitative accuracy.
• Image correction methods are essential for reliable uptake quantification.

Purpose of the Study:

• To determine the optimal SPECT acquisition and reconstruction protocol for ²²³RaCl₂.
• To evaluate image quality parameters and septal penetration correction.
• To establish methods for accurate patient dosimetry in ²²³RaCl₂ theranostics.

Main Methods:

• SPECT imaging of ²²³RaCl₂ was performed using a Jaszczak phantom and dual-headed gamma camera.
• Image quality parameters (noise, contrast, CNR, recovery coefficient) were assessed.
• OSEM/MLEM reconstruction with a Butterworth filter and septal penetration correction were applied and analyzed using MATLAB®.

Main Results:

• An 89 keV energy window (24% wide) with OSEM/MLEM reconstruction (8 subsets, 4 iterations) and a Butterworth filter (order 10, cutoff 0.48 cycles·cm⁻¹) yielded optimal image quality.
• Effective septal penetration correction was achieved.
• Recovery coefficient evaluation was successfully performed for uptake correction.

Conclusions:

• An optimized SPECT protocol was identified for ²²³RaCl₂ imaging.
• The established methods enable accurate quantitative SPECT imaging for theranostic dosimetry.
• This work facilitates improved patient-specific treatment planning and monitoring.