PhD Defense | Tiffany-Thao Nguyen | Medical Radioisotope Supply Chain Design for Security: Efficiency, Alignment, and Speed

Medical Radioisotope Supply Chain Design for Security: Efficiency, Alignment, and Speed

Medical radioisotopes are vital to modern healthcare, yet their supply chains are fragile due to constant radioactive decay, limited global production facilities, and strict timing requirements. These challenges mean that even small delays or disruptions can lead to shortages that affect patient care. This thesis develops mathematical models to better understand and improve the supply chain for molybdenum‑99 (Mo‑99), the main source of technetium‑99m (Tc-99m) used in millions of medical procedures worldwide. The models incorporate radioactive decay, uncertain supply chain lead times, and other logistic particularities unique to a medical radioisotope supply chain to enable evaluation of scenarios with the real‑world constraints of the system.

The first part of the work demonstrates that a transport scheduling method focused on maximizing delivered inventory, rather than meeting specific flight departures, can significantly outperform common expectations and experience. Greater flexibility—such as allowing shipments on multiple possible flights—further increases usable supply. The second part introduces a global reactor scheduling framework that accounts for reactor production outages, downstream capacities, and overall supply availability. Coordinated reactor schedules substantially reduce shortages and highlight that improving supply security requires aligning production, processing, and distribution decisions. Overall, the thesis provides tools and insights to help decision makers evaluate performance, explore alternative scenarios, and design more resilient medical radioisotope supply chains.

Promoter:

• Joachim Arts (ULuxembourg)

SCK CEN mentors:

• Jared Wight
• Bernard Ponsard