Validation of a method for estimating peak skin dose from CT-guided procedures

Area of Science:

• Medical Physics
• Radiology
• Interventional Radiology

Background:

• A published method for estimating peak skin dose (PSD) from CTDIvol requires validation.
• CT-guided procedures necessitate accurate PSD assessment for patient safety.

Purpose of the Study:

• To validate a method for estimating PSD from CTDIvol during CT-guided ablation procedures.
• To compare calculated PSD and total CTDIvol with measured PSD.

Main Methods:

• Radiochromic film was used to measure PSD in 68 patients undergoing 46 CT-guided ablation procedures.
• PSD was estimated using a formula incorporating helical and axial CTDIvol.
• Statistical analysis included paired t-tests and Bland-Altman analysis.

Main Results:

• The validated method significantly differed from measured PSD (P < 0.0001).
• Measured PSD showed no significant difference from total CTDIvol (P = 0.27).
• Bias for total CTDIvol as a PSD indicator was 3.97%.

Conclusions:

• Scanner-reported CTDIvol may be a reasonable, immediately available indicator of PSD during CT-guided procedures.
• The validated estimation method requires further refinement.
• Additional validation across different CT scanner models is recommended.