Leite Rocha, Pedro (2011) Novel approaches to radiotherapy treatment scheduling. PhD thesis, University of Nottingham.
Radiotherapy represents an important phase of treatment for a large number of cancer patients. It is essential that resources used to deliver this treatment are used efficiently. This thesis approaches the problem of scheduling treatments in a radiotherapy centre. Data about the daily intake of patients are collected and analysed.
Several approaches are presented to create a schedule every day. The first presented are constructive approaches, developed due to their simplicity and low computational requirements. The approaches vary the preferred treatment start, machine utilisation reservation levels, and the frequency and number of days in advance with which schedules are created.
An Integer Linear Programming (ILP) model is also presented for the problem and used in combination with approaches similar to the ones above. A generalisation of the constructive utilisation threshold approach is developed in order to vary the threshold level for each day according to how far it is from the current day. In addition, the model is evaluated for different sizes of the problem by increasing the rate of patient arrivals per day and the number of machines available. Different machine allocation policies are also evaluated.
An exact method is introduced for finding a set of solutions representing the whole Pareto frontier for integer programming problems. It is combined with two robust approaches: the first considers known patients before they are ready to be scheduled, while the second considers sets of predicted patients who might arrive in the near future. A rescheduling approach is also suggested and implemented. A comparison is made amongst the best results from each group of approaches to identify the advantages and disadvantages of each. The robust approaches are found to be the best alternative of the set.
|Item Type:||Thesis (PhD)|
|Uncontrolled Keywords:||ILP, integer linear programming, treatment scheduling, time mangement|
|Faculties/Schools:||UK Campuses > Faculty of Science > School of Computer Science|
|Deposited By:||Dr. Pedro Leite Rocha|
|Deposited On:||01 Mar 2012 10:28|
|Last Modified:||01 Mar 2012 10:28|
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