Internal dosimetry study of [⁸²Rb]Cl using a long axial field-of-view PET/CT

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Radiological Physics

Background:

• Long axial field-of-view (LAFOV) positron emission tomography (PET) enables comprehensive organ imaging in a single position.
• This capability is crucial for dynamic whole-body imaging, especially with short-lived radioisotopes like Rubidium-82 chloride (⁸²Rb).

Purpose of the Study:

• To determine the absorbed radiation dose in target organs using [⁸²Rb]Cl with LAFOV PET/CT.
• To compare radiation dose estimates obtained through MIRD formalism and voxel dosimetry.

Main Methods:

• Three subjects underwent dynamic [⁸²Rb]Cl PET/CT scans for 7 minutes after injection.
• Absorbed doses in organs like the heart, kidneys, and lungs were calculated using both MIRD and voxel dosimetry methods.

Main Results:

• Absorbed doses for the heart wall ranged from 1.84 to 2.78 μGy/MBq (MIRD) and 1.57 to 3.92 μGy/MBq (voxel dosimetry).
• Kidney absorbed doses were 2.76–5.73 μGy/MBq (MIRD) and 3.22–5.37 μGy/MBq (voxel dosimetry).
• Lung absorbed doses were 0.94–1.88 μGy/MBq (MIRD) and 0.98–1.92 μGy/MBq (voxel dosimetry).
• Total body effective dose ranged from 0.50 to 0.76 μSv/MBq.

Conclusions:

• Dynamic LAFOV PET/CT can effectively assess radiation dose from [⁸²Rb]Cl.
• The estimated radiation doses are lower than those reported in existing literature.