Experimental fluence-modulated proton computed tomography by pencil beam scanning

Area of Science:

• Medical Imaging
• Particle Therapy
• Radiological Physics

Background:

• Proton computed tomography (pCT) offers potential advantages over X-ray CT.
• Pencil beam scanning (PBS) enables precise proton delivery.
• Optimizing pCT protocols for dose reduction is crucial.

Purpose of the Study:

• To demonstrate the feasibility of fluence-modulated proton computed tomography (FMpCT) using PBS.
• To evaluate image quality and dose savings of FMpCT.
• To compare PBS pCT with broad beam pCT.

Main Methods:

• A pCT prototype utilizing PBS was employed with a cylindrical water phantom.
• FMpCT scans were performed with varying fluence modulation factors (FMF).
• Image quality (accuracy, noise) and dose savings via Monte Carlo simulation were assessed.

Main Results:

• PBS pCT scans achieved comparable noise and accuracy to broad beam pCT.
• FMpCT preserved image quality in the region of interest.
• Dose reductions of up to 60% were observed at the object's edge with FMF of 20%.

Conclusions:

• FMpCT using PBS is feasible and maintains image accuracy.
• Significant dose reduction is achievable with FMpCT.
• This technique holds promise for safer proton imaging.