Patient doses from hybrid SPECT-CT procedures

Area of Science:

• Medical Physics
• Radiology
• Nuclear Medicine

Background:

• Hybrid SPECT-CT systems are increasingly used for diagnostic imaging.
• Accurate estimation of patient effective dose is crucial for radiation protection in these procedures.
• Variations in imaging protocols can lead to inconsistent radiation exposure.

Purpose of the Study:

• To estimate patient effective doses from hybrid SPECT-CT procedures in Bulgaria.
• To analyze the variations in dose across different systems and examination types.
• To propose optimization strategies and diagnostic reference levels for SPECT-CT examinations.

Main Methods:

• Involved all four SPECT-CT systems in Bulgaria, estimating doses for approximately 100 patients per system.
• Considered ten types of diagnostic SPECT-CT examinations.
• Calculated SPECT effective doses using ICRP 53 and ICRP 80 conversion coefficients.
• Determined CT effective doses using CT-Expo software and retrospective data (CTDIvol, DLP).
• Performed parallel CT dose estimation using NRPB conversion coefficients where applicable.

Main Results:

• Significant variations in current SPECT-CT imaging practices were identified.
• Effective doses were estimated for both SPECT and CT components of the hybrid procedures.
• Data provided a basis for understanding dose distributions in Bulgarian SPECT-CT facilities.

Conclusions:

• The findings highlight the need for standardized protocols and optimization in SPECT-CT imaging.
• Proposed diagnostic reference levels can guide practice and reduce unnecessary patient exposure.
• Further research may focus on specific protocols and advanced dose reduction techniques.