General applications of optimal control theory in cancer chemotherapy.

There are an increasing number of clinical papers dealing with the continuous delivery of an anticancer drug to patients. In this paper, two basic theoretical models are presented of cancer growth under the action of a continuously delivered anticancer drug. The therapeutic objective is to obtain the nature of the control agent that can drive the tumour population to a desired level so as to penalize excessive usage of the drug and to keep deviations of the tumour population from the desired level to a minimum. This gives rise to a certain type of optimal control problem. The nature of the optimal controller for each model is presented. The optimal control approach leads to a therapeutic strategy that may be of relevance to the clinical studies and this is investigated.