A New Dual-purpose Quality Control Dosimetry Protocol for Diagnostic Reference-level Determination in Computed...

Area of Science:

• Medical Physics
• Radiological Protection
• Diagnostic Imaging

Background:

• Diagnostic reference levels (DRLs) are crucial for patient protection against medical radiation exposure.
• Traditional methods for determining DRLs in computed tomography (CT) involve direct dose measurement and data collection, which can be resource-intensive.
• Existing quality control (QC) databases offer a potential avenue for simplifying DRL determination.

Purpose of the Study:

• To propose and validate a prospective, dual-purpose quality control dosimetry protocol for determining DRLs in CT examinations.
• To simplify the process of DRL determination for regulatory authorities and QC service providers.
• To assess the agreement of the proposed method with established dose survey techniques.

Main Methods:

• A prospective dual-purpose QC dosimetry protocol was developed.
• The protocol was applied to five CT scanners in Shiraz, Iran, for various examinations (head, abdomen/pelvis, sinus, chest, lumbar spine).
• Results were compared against parallel measurements using direct data collection and a retrospective QC-based dose survey method.

Main Results:

• DRLs were successfully determined for multiple CT examination types using the proposed protocol.
• The new method showed excellent agreement (within ~6%) with established data collection and QC-based dose survey methods.
• The observed agreement is well within the International Atomic Energy Agency's acceptable tolerance levels (±20%) for QC-based methods.

Conclusions:

• The proposed prospective QC dosimetry protocol provides a simplified and effective approach for determining DRLs in CT.
• This method facilitates accurate patient dose assessment and enhances radiological protection.
• The protocol is practical for implementation by quality control service providers, aiding national DRL establishment.