Farinaz Forouzannia| Applied Math, University of Waterloo
Mathematical modeling of second cancer risks arising from low dose radiation
Traditional radiotherapy as a part of cancer treatment applies high doses of energy to eradicate malignant cells. This therapy stops the proliferation of cancer cells by damaging the DNA of these cells. The ability of radiation to kill cancer cells increases with higher doses of energy, however it has huge side effects on the normal surrounding tissue. Over the past few years, much progress has been made in radiotherapy, nevertheless the attainable benefits from the treatment must be evaluated and quantified to be of clinical relevance. The Tumour control probability (TCP) is a methodology that quantifies the probability of destroying or removing the malignant cells for a variety of radiation therapy schedules. In addition, the possible side effects of radiation therapy should be assessed along with the quality of treatment. Second cancers are one of the major concerns arising as a result of radiation therapy and the relative second cancer risks, in long term radiotherapy survivors, has become of increasing concern in recent years. Because of the long latency period in the development of second cancers, available data often relates to old treatment protocols and methods. Therefore, mathematical modeling is often one of the very few approaches available in estimating the risks of second cancers. It has been known that intermediate and high dose radiation has serious side effects. For example, acute or prolonged exposure to periods of radiation, results in harmful clinical consequences in exposed individuals. For very low doses of radiation the situation appears to be different. The effects of very low-doses of radiation are not completely understood. Hence, the excessive use of radiation in medicine as well as in technological developments has increased global concern about the possible risks of low dose radiation exposure.
In this seminar, I will present a comprehensive literature review of more applicable TCP models along with our preliminary results on more clinically relevant TCP models. In addition, I will discuss a few possible models for estimating the risks of second cancers. Finally, I will present an introduction on possible cancer risks attributed to lower doses of radiation.