Modelling Tumour Control in External Beam Radiotherapy for Prostate Cancer

Balderson, Michael

Modelling Tumour Control in External Beam Radiotherapy for Prostate Cancer

atmire.migration.oldid	3716
dc.contributor.advisor	Kirkby, Charles
dc.contributor.author	Balderson, Michael
dc.date.accessioned	2015-09-30T21:06:24Z
dc.date.available	2015-11-20T08:00:44Z
dc.date.issued	2015-09-30
dc.date.submitted	2015	en
dc.description.abstract	Modeling tumour control for prostate treatments can be challenging. Models used to predict tumour control are typically based on the well known linear-quadratic (LQ) model for cell survival. The LQ model accurately predicts cell killing for a given radiation dose in most cases, however in some cases the LQ model falls short and LQ model predictions differ from what has been observed experimentally. Cell survival following low radiation doses <1Gy and radiation induced bystander effects are two examples where the LQ model potentially falls short at modelling cell survival following an absorbed radiation dose. Using mathematical models that account for radiation induced bystander and low dose hypersensitivity effects, we look at how these effects potentially change predicted outcomes of tumour control when compared to standard LQ predictions. We start by investigating how the basic LQ model predicts tumour control under large geometric miss errors under intensity modulated radiation therapy (IMRT) and volume modulated arc therapy (VMAT) modalities. Next, we look at the geometric miss scenario again, but rather than compare two different delivery techniques we investigate how radiation induced bystander effects potentially change predicted tumour control under geometric miss cases. We then expand on this idea and study how radiation induced bystander effects potentially influence predicted outcome under heterogeneous dose distributions. Finally, we compare the relative biological effectiveness (RBE) of bystander effects with low dose hypersensitivity effects and spectral effects for out-of-field radiation doses. The majority of this work focused on how radiation induced bystander effect changed biological modeling of tumour control in external beam radiotherapy for prostate cancer. This work ultimately demonstrates that bystander effects can modify predicted outcomes of tumour control. We have shown that bystander effects potentially improve TCP under geometric miss and that bystander effects may relax the common planning constraint of aiming for dose homogeneity within a target volume.	en_US
dc.identifier.citation	Balderson, M. (2015). Modelling Tumour Control in External Beam Radiotherapy for Prostate Cancer (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/26965	en_US
dc.identifier.doi	http://dx.doi.org/10.11575/PRISM/26965
dc.identifier.uri	http://hdl.handle.net/11023/2575
dc.language.iso	eng
dc.publisher.faculty	Graduate Studies
dc.publisher.institution	University of Calgary	en
dc.publisher.place	Calgary	en
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject	Biology--Cell
dc.subject	Biophysics
dc.subject	Physics
dc.subject.classification	Bystander	en_US
dc.title	Modelling Tumour Control in External Beam Radiotherapy for Prostate Cancer
dc.type	doctoral thesis
thesis.degree.discipline	Physics and Astronomy
thesis.degree.grantor	University of Calgary
thesis.degree.name	Doctor of Philosophy (PhD)
ucalgary.item.requestcopy	true