Determining the quality control frequency of an MR-linac using risk matrix (RM) analysis

Area of Science:

• Medical Physics
• Radiotherapy Technology
• Quality Assurance

Background:

• Routine quality control (QC) in radiotherapy is guided by professional standards.
• Current QC frequencies may not be optimal for all institutional settings.
• Magnetic Resonance linacs (MR-linacs) require precise QC for patient safety and treatment efficacy.

Purpose of the Study:

• To develop and validate a novel method for determining optimal QC frequencies for MR-linacs.
• To utilize risk matrix (RM) analysis for data-driven QC frequency optimization.
• To ensure continued high performance of radiotherapy treatment machines.

Main Methods:

• A Magnetic Resonance linac (MR-linac) was used as the test platform.
• Six routine QC items were analyzed using Failure Mode and Effects Analysis (FMEA).
• Severity (S), Occurrence (O), and Detection (D) were assessed to calculate risk, informing new QC frequencies.

Main Results:

• New QC frequencies were determined for six critical QC items.
• One frequency remained unchanged, two decreased, and three increased compared to old frequencies.
• The new frequencies demonstrated a reduction in the risk of machine failure (E = O/D).

Conclusions:

• Risk matrix (RM) analysis is a valuable tool for optimizing linac QC frequency.
• The proposed method allows for QC adjustments while maintaining high treatment machine performance.
• This approach supports efficient and effective quality control in radiotherapy clinics.