Improving patient capacity for gynecological brachytherapy through an optimization model for Iridium-192 source decay: A case study at Udon Thani Cancer Hospital

Abstract

The radioactive decay of the Iridiu¬m-192 (Ir-192) source used in brachytherapy for gynecological cancer presents a significant scheduling challenge at Udon Thani Cancer Hospital. As the source decays over its 73.83-day half-life, treatment dwell times increase, creating a bottleneck that reduces the number of patients that can be treated daily. This research introduces an optimization model to counteract this effect by defining the optimal daily patient schedule. By analyzing the variables of source age and activity of source, the model prescribes a dynamic capacity: 9 patients per day for the initial 10 days post-replacement, reducing to 8 patients for days 11-82, and finally 7 patients from day 83 onward. The radioactivity readings revealed that when the source had levels of 9.1 and 4.59 curies (Ci), the encouragement capacity decreased by one patient. This enables Udon Thani Cancer Hospital to effectively manage resources and maximize service delivery throughout the entire lifecycle of the radiation source. 

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