[Evaluation of Appropriate Treatment Infrastructure for Radionuclide Therapy Through Discrete Event Simulation].

Purpose: Radionuclide therapy often involve long waiting periods due to limited numbers of radioisotope therapy rooms and special measures rooms, and strict regulations. The purpose of this study was to estimate the waiting period for radionuclide therapy, considering the increased utilization of nuclear medicine and greater demand due to new drugs. The study also examined possible factors that may limit the treatment provision system and investigate appropriate treatment environments that could shorten the waiting period.

Method: We developed a discrete event simulation, using three prefectures as a model, to predict the number of patients with a long waiting period and determine the effectiveness of environmental measures designed to shorten the waiting period. The model took considered the demand for radionuclide therapy and medical resources, such as the number of treatment beds, as input values.

Results: The simulation predicted that, within 4 years after the introduction of [¹⁷⁷Lu]Lu-PSMA-617, the number of patients waiting >180 days for treatment would increase significantly in all three prefectures. The limited number of beds was the leading cause of the long waiting period. However, just increasing the number of beds was ineffective for reducing the waiting period in some facilities due to regulatory factors, and measures to improve the drainage capacity were also necessary.

Conclusion: The number of patients with a long waiting period is expected to increase significantly due to the rapid increase in demand for radionuclide therapy. A combination of measures, including increasing the number of beds, improving drainage capacity, and better utilization of available medical resources through interfacility cooperation, are factors that need urgent attention to reduce the waiting time for radionuclide therapy.