Applying Lean Six Sigma to improve efficiency in outpatient iodine-131 therapy: reducing process time and material waste.

At our institution, outpatient radioactive iodine-131 (¹³¹I) therapy requires coordination across multiple teams and is prone to inefficiencies. Patients and staff experienced process delays on the day of dose administration due to extended treatment times, inconsistent workflows and material waste. This project aimed to reduce overall process time (OPT) by 25% within 12 months while maintaining radiation safety and minimising material costs associated with room wrapping, a separate process involving the protection of treatment room surfaces from radioactive contamination.Workflow data were collected from 55 patients treated between January 2022 and June 2024 to establish a baseline. Quality improvement methods using the Lean Six Sigma (Define, Measure, Analyse, Improve, Control) framework were applied to identify inefficiencies and implement changes through two sequential improvement cycles focused on standardising processes governing patient arrival, predosing and discharge. Wrapping workflow interventions simplified material use and standardised the wrapping order.After the first improvement cycle, average OPT decreased from 156.3 min to 114.2 min (26.9% reduction from baseline). The proportion of patients with an OPT under 2 hours increased from 9.1% to 61.9%. After the second improvement cycle, OPT further decreased to 103.0 min (34.1% reduction from baseline), and 73.3% of patients were discharged within 2 hours. Material costs per treatment decreased from $35.80 to $19.00 (46.9% reduction), with additional unquantified cost and time savings from procedure scheduling changes.The sequential application of Lean Six Sigma strategies significantly reduced process time and material costs in outpatient ¹³¹I therapy without compromising radiation safety standards. These interventions demonstrate how structured quality improvement can enhance staff efficiency and resource use, providing a replicable model for other complex clinical workflows.