Dose-volume delivery guided proton therapy using beam on-line PET system

Area of Science:

• Medical Physics
• Radiotherapy
• Nuclear Imaging

Background:

• Proton therapy offers precise tumor irradiation using Bragg peaks.
• Accurate verification of the proton-irradiated volume is essential for effective dose delivery.
• Positron emission tomography (PET) can detect annihilation gamma rays to map activity.

Purpose of the Study:

• To develop and evaluate a system for real-time monitoring of proton-irradiated volumes.
• To enable dose-volume delivery guided proton therapy (DGPT) using PET imaging.
• To assess the accuracy of a novel beam ON-LINE PET system (BOLPs).

Main Methods:

• Constructed a planar-type PET apparatus with ~2 mm spatial resolution (BOLPs) in a proton treatment room.
• Irradiated a gelatinous water target with 16O nuclei and a rabbit with protons at varying energy levels.
• Measured activity distribution and position using BOLPs immediately after proton irradiation.

Main Results:

• Observed activity distribution range changes correlated with physical range changes within 2 mm.
• Successfully imaged proton-irradiated volumes in both phantom and rabbit models.
• Demonstrated clear identification of proton-irradiated volumes by comparing BOLPs measurements under different beam conditions.

Conclusions:

• The BOLPs system accurately visualizes proton-irradiated volumes with high spatial resolution.
• Real-time PET imaging facilitates precise dose verification in proton therapy.
• This technology supports the advancement of dose-volume delivery guided proton therapy (DGPT).