Personnel protection during aerosol ventilation studies using radioactive technetium (Tc99m)

Area of Science:

• Nuclear Medicine
• Radiation Safety
• Medical Imaging

Background:

• Nebulizing devices utilizing radioactive Technetium-99m (Tc99m) are employed in ventilation studies.
• Potential for room air contamination and personnel exposure exists with Tc99m nebulizers.
• Existing personal protective equipment (PPE) may be insufficient to mitigate exposure risks.

Purpose of the Study:

• To evaluate ambient air concentrations and personnel exposure during Tc99m ventilation studies.
• To assess the effectiveness of standard PPE and enhanced protective measures against Tc99m contamination.
• To determine the extent of contamination in the examination room environment.

Main Methods:

• Monitoring of ambient air concentrations of Tc99m in the examination room.
• Assessment of personnel exposure and contamination on clothing, hair, and airways.
• Comparison of contamination levels with standard PPE versus enhanced protective methods (e.g., respirators).

Main Results:

• Maximum permissible Tc99m concentration was not exceeded, but nasal passage deposition reached 11,000 disintegrations/min.
• Conventional surgical masks were ineffective; enhanced methods reduced Tc99m levels by 19% (p > 0.10).
• Significant reduction in overall Tc99m levels (78%) and deposition (to ≤50 disintegrations/min, p < 0.001) achieved with enhanced protection.

Conclusions:

• Tc99m ventilation studies necessitate more effective personal protective devices due to contamination risks.
• Patient-related factors, such as poor oral seal, contribute significantly to personnel contamination.
• High-efficiency respirators and isolation techniques are crucial for minimizing radiation exposure in nuclear medicine procedures.