38. Application of lean-six-sigma methodology in radiotherapy: Breast daily repositioning case

Purpose The concept of quality assurance in radiotherapy encompasses a comprehensive approach to all activities in the department. When hypo-fractionation regiment is adopted, the need of a continuous quality procedures updating is self-evident. At this aim, the Lean Six Sigma Methodology (LSSM) has been applied. LSSM was introduced in industry for providing near-perfect services to large processes, by reducing improbable occurrence. It consists of the synergetic adoption of two methods: (i) create a continuous process flow eliminating waste (Lean); (ii) reduce process variation (Six sigma). LSSM has been prospectively applied to breast patient repositioning. This is the first time the LSSM has been rigorously applied to a RT process. Methods Breast patients treated by hypo-fractionated RT in SIB delivered through VMAT technology with daily 2D-2D matching were considered. The five DMAIC (Define, Measure, Analyze, Improve, Control) LSSM steps were applied by an interdisciplinary team. The process was retrospective measured over 30 months (Jul2014–Dec2016) by querying the RT RecordV distribution symmetry improvement (Skewness moved from 1.4 to 1.1) and outlier eduction, verified by Kurtosis diminution, demonstrated better “normalization” of the procedure after the LSSM application. Conclusions LSSM was successfully applied in a RT department, allowing the breast repositioning matching procedure to be redesigned.