SU-E-J-173: Can a Metal Artifact Reduction Algorithm Affect Accuracy of Dose Calculation?

Area of Science:

• Medical Physics
• Radiotherapy
• Image Processing

Background:

• Metal implants, like hip prostheses, cause streak artifacts in CT scans.
• These artifacts hinder accurate delineation of targets and critical organs in radiotherapy planning.
• Existing methods struggle to mitigate these image quality issues.

Purpose of the Study:

• To evaluate a commercial metal artifact reduction (MAR) algorithm.
• To assess its impact on image quality in radiotherapy planning CT scans.
• To determine the effect of MAR on dose calculation accuracy and organ delineation.

Main Methods:

• Nine patients with hip prostheses undergoing radiotherapy were included.
• CT images were reconstructed with and without MAR correction.
• Prostate, bladder, and rectum contours were delineated; overlap index and dose calculations were performed.

Main Results:

• MAR significantly improved image quality, reducing streak artifacts.
• Dose calculation accuracy remained unaffected when using MAR corrected images.
• Improved organ delineation accuracy was observed, particularly for bilateral hip replacements.

Conclusions:

• Commercial MAR algorithms effectively enhance CT image quality in the presence of metal implants.
• MAR does not compromise dose calculation accuracy in radiotherapy.
• Enhanced organ delineation accuracy with MAR offers significant dosimetric advantages.