Effectiveness of Various Shields In Minimizing Radiation Exposure for Lu-177 Based Radiopharmaceutical Delivery
Abstract
Purpose
Occupational exposure during Lutetium-177 (Lu-177) radiopharmaceutical therapy depends on administration technique, shielding configuration, and staff proximity—temporal and spatial. This study quantified extremity and whole-body exposure contributions for varying Lu-177 administration workflows.
Methods
Exposure estimates were evaluated for a representative 200 mCi Lu-177 therapy dose (Pluvicto™/Lutathera™) using a gamma constant of 0.028 mrem·hr⁻¹·mCi⁻¹ at 1 m. Four different workflows were evaluated: (1) gravity-based vial using a lead pig, (2) handheld ClearView® syringe shield without cradle, (3) ClearView® admin and transport shield with cradle, and (4) a shielded infusion pump system. Instantaneous radiation exposure rates were also collected using two ion-chamber survey meters with and without the corresponding shielding as necessary. Per-infusion technologist extremity and whole-body exposure contributions were estimated assuming clinically realistic handling times.
Results
Shielding attenuation for the lead pig, Clearview syringe-shield, Clearview admin and transport shield and shielded infusion pump were approximately measured as 98%, 77%, 90% and 98% respectively. Per-infusion extremity doses ranged from 0.44 mrem for gravity-based administration to 2.55–2.71 mrem for syringe-based workflows with standard shielding, increasing to 12.6 mrem for injector-based delivery due to brief unshielded handling. Whole-body doses were low across all configurations, ranging from 0.06–0.58 mrem for gravity-based workflows, 0.26–1.31 mrem for syringe-based techniques, and approximately 1.9 mrem for injector-based delivery. Use of a syringe cradle with L-block reduced whole-body and lens dose by 55–80% relative to standard syringe shielding. For all workflows, calculated annual infusion limits(>3000 infusions/year) based on whole-body dose substantially exceeded typical clinical workloads.
Conclusion
Lu-177 therapy administration results in minimal occupational exposure when commonly available shielding and standard ALARA practices are employed. Although patient-emitted radiation contributes additional exposure after infusion, routine use of distance and shielding is expected to keep total technologist dose well below regulatory limits, supporting Lu-177 therapy as an occupationally safe procedure.