A queuing approach for radiotherapy treatment capacity planning

Radiotherapy, one of most important treatments for patients with cancer, relies on expensive equipment and follows complex treatment processes. This paper focuses on the capacity planning of Linear Accelerators (LINAC), the bottleneck resources of radiotherapy treatment. We propose a novel queuing approach considering each LINAC time slot as a server instead of the traditional LINAC servers. This novel queuing perspective allows elegant modeling the complex treatment process characterized by re-entrance of a patient as her service time on a given time slot server, which makes solving capacity planning problem with multiple types of patients and LINACs easier through mixed integer programming. In this paper, two capacity planning problems are discussed: target waiting time verification and case-mix optimization. Numerical experiments with different scenarios are also conducted.