Occupational radiation dose associated with Rb-82 myocardial perfusion positron emission tomography imaging

Area of Science:

• Nuclear Medicine
• Radiology
• Medical Physics

Background:

• Assessing staff radiation exposure during rubidium-82 (Rb-82) myocardial perfusion positron emission tomography (PET) is crucial for safety.
• Comparison with technetium-99m (Tc-99m) based imaging provides context for radiation dose levels.

Purpose of the Study:

• To quantify staff radiation doses associated with rest and stress Rb-82 PET imaging.
• To compare radiation exposure from Rb-82 PET with Tc-99m MIBI imaging.

Main Methods:

• Radiation exposure was measured using a pressurized ion chamber during 50 Rb-82 PET examinations.
• Staff doses were compared to those from Tc-99m MIBI pharmacologic stress tests.
• Dose measurements were taken at various distances and time points relative to radiotracer infusion.

Main Results:

• Mean staff dose during Rb-82 infusion and PET acquisition was 0.45 ± 0.25 µSv.
• Exposure during routine Rb-82 stress testing was comparable to background levels.
• However, doses at 0.5 m during Rb-82 infusion (0-7 min) reached 19.1 ± 5.8 µSv, significantly higher than Tc-99m MIBI exposure (1.075 ± 0.32 µSv).

Conclusions:

• Routine Rb-82 PET procedures result in lower staff radiation doses compared to Tc-99m MIBI.
• Significant radiation exposure can occur in close proximity to patients during Rb-82 infusion.
• Strict adherence to source distance and limited contact times is essential during Rb-82 administration.