Abstract:
Single fraction Targeted Intraoperative radiotherapy (Targit) is a new
concept of partial breast irradiation that is being tested in randomised
trials. Targit allows accurate dosimetry, avoids delay and has logistic
advantages.
We present a mathematical model for growth of a solid tumour in
breast, its surgical excision and adjuvant radiotherapy. We use the
linear quadratic model to compute the survival probabilities for both
tumour cells and breast tissue and simulate the effects of external
beam radiotherapy and Targit.
Local recurrence could arise from stray tumour cells or from morphologically
normal cells in the tumour bed that harbour predisposing
genetic changes, such as loss of heterozygosity on tumour suppressor
genes (LOH).
Our mathematical model predicts that Targit would eliminate all
these sources of recurrence, whereas the fractionated external beam
radiotherapy would eliminate stray tumour cells, but allows the cells
with LOH to accumulate radiation induced DNA damage.
Our work is an initial attempt to model a biologically complex phenomenon
that has until now received little attention in the literature.
We hope to extend our model to 3-dimensions and to the cellular
level in tandem with molecular experiments to study normal tissue
effects of radiotherapy that are ongoing at our centre.
Paper covering this presentation published in J. Theor. Biol.
awarded a Cancer Research UK pilot project research grant
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