SAVI catheter digitization impact: A single institution multiuser uncertainty study

Area of Science:

• Medical Physics
• Radiation Oncology
• Brachytherapy

Background:

• High-dose-rate (HDR) breast brachytherapy utilizes Strut Adjusted Volume Implant (SAVI) devices for precise tumor targeting.
• Assessing the impact of catheter digitization variability is crucial for ensuring treatment plan accuracy and patient safety.

Observation:

• Six physicists independently digitized SAVI catheters across four clinical cases, introducing digitization variability.
• Plans were evaluated based on PTV_Eval D90, V150, V200, and OARs (Chest-Wall/Ribs and Skin) D0.03cc, D0.1cc, D1cc, D2cc.
• Average dwell positional digitization uncertainties were 0.36 mm, with a maximum of 0.75 mm.

Findings:

• Despite digitization variations, average PTV_Eval D90, V150, and V200 showed clinically insignificant deviations.
• All organs at risk (OAR) constraints for Chest-Wall/Ribs and Skin were met across all digitized plans.
• The study demonstrated the robustness of SAVI treatment plans to minor digitization uncertainties.

Implications:

• SAVI planning constraints are stable within acceptable digitization variations, ensuring reliable treatment delivery.
• Uncertainty analysis aids in standardizing digitization practices and establishing action levels for quality assurance.
• This study validates the reliability of SAVI catheter digitization in HDR brachytherapy for breast cancer treatment.