[Statistical Process Control (SPC) can help prevent treatment errors without increasing costs in radiotherapy].

Area of Science:

• Medical Physics
• Radiation Oncology
• Quality Improvement

Context:

• Accurate patient positioning is critical in radiotherapy.
• Variability in patient set-up can lead to treatment inaccuracies.
• Existing monitoring methods may not proactively prevent errors.

Purpose:

• To implement Statistical Process Control (SPC) for monitoring radiotherapy patient set-up.
• To identify and eliminate root causes of set-up errors when process stability is lost.
• To proactively prevent set-up errors in all treatment sessions.

Summary:

• Radiotherapy set-up errors in medial-lateral, cranial-caudal, and anterior-posterior dimensions were measured.
• Control limits were established, and real-time monitoring using control charts was performed.
• When process instability was detected, treatment was interrupted, root causes identified, and corrective actions implemented.

Impact:

• SPC effectively controls variability due to assignable causes, rather than patient-to-patient variations.
• This method enables proactive error prevention across all treatment sessions for all patients.
• The SPC protocol reduces control costs while enhancing treatment accuracy and safety.