Medicine and Health Sciences Commons^™

Translational Study Of Liver Cancer And Hypertrophy: Translich, Mauro Enrique Tun Abraham

Electronic Thesis and Dissertation Repository

Abstract

Background: Associating liver partition with portal vein ligation for staged-hepatectomy (ALPPS) is a technique for inducing accelerated hypertrophy in patients with insufficient future liver remnant (FLR). It remains unknown whether this hypertrophy may lead to rapid cancer cell dissemination and/or alteration of immune cell/function reconstitution in the FLR. We aimed to determine if the rapid hypertrophy during ALPPS procedure results in more circulating tumour cell (CTCs) dissemination and whether the FLR remains immunologically competent in patients with CRLM.

Methods: In our prospective, observational, 2-arm study, we assessed the utility of CTCs as an evaluation tool for disease dissemination. Moreover, …

Investigating Stromal Contributions To The Regulation Of Cancer Progression, Krista M. Vincent

Electronic Thesis and Dissertation Repository

Tumours are not insular masses of proliferating cells, rather tumour cells evolve within a complex local environment complete with matrix, stromal, and immune components. Therefore, successful tumour growth and eventual metastasis is not determined solely by tumour cells themselves, but also by the fitness advantage or disadvantage conferred by their local environment. However, many of our current cancer models are composed solely of tumour cell isolates. As tumour fitness is dependent on the entire local cellular context, we were interested in characterizing the accuracy of cell lines as models of the tumour microenvironment, with a focus on the secreted Frizzled-related …

Assessment Of Post-Treatment Imaging Changes Following Radiotherapy Using Magnetic Susceptibility Techniques, Jean-Guy Belliveau

Electronic Thesis and Dissertation Repository

Radiation therapy (RT) is a common treatment for brain neoplasms and is used alone or in combination with other therapies. The use of RT has been found to be successful in controlling tumors and extending the overall survival of patients; however, there are many unanswered questions regarding radiotherapy effects in the normal brain surrounding or infiltrated by tumor. Changes to the vascular and parenchyma have been documented, and more recently inflammatory mechanisms have been postulated to play a role in radiation injury. Traditional imaging techniques used within the clinic (CT and MRI) are often lacking in their ability to differentiate …

Optimizing Respiratory Gated Intensity Modulated Radiation Therapy Planning And Delivery Of Early-Stage Non-Small Cell Lung Cancer, Ilma Xhaferllari

Electronic Thesis and Dissertation Repository

Stereotactic ablative body radiotherapy (SABR) is the standard of care for inoperable early-stage non-small cell lung cancer (NSCLC) patients. However, thoracic tumours are susceptible to respiratory motion and, if unaccounted for, can potentially lead to dosimetric uncertainties. Respiratory gating is one method that limits treatment delivery to portions of the respiratory cycle, but when combined with intensity-modulated radiotherapy (IMRT), requires rigorous verification. The goal of this thesis is to optimize respiratory gated IMRT treatment planning and develop image-guided strategies to verify the dose delivery for future early-stage NSCLC patients.

Retrospective treatment plans were generated for various IMRT delivery techniques, including …

Non-Invasive Imaging For The Assessment Of Cardiac Dose And Function Following Focused External Beam Irradiation, Omar El-Sherif

Electronic Thesis and Dissertation Repository

Technological advances in imaging and radiotherapy have led to significant improvement in the survival rate of breast cancer patients. However, a larger proportion of patients are now exhibiting the less understood, latent effects of incidental cardiac irradiation that occurs during left-sided breast radiotherapy. Here, we examine the utility of four-dimensional computed tomography (4D-CT) for the accurate assessment of cardiac dose; and a hybrid positron emission tomography (PET) magnetic resonance imaging (MRI) system to longitudinally study radiation-induced cardiac effects in a canine model.

Using 4D-CT and deformable dose accumulation, we assessed the variation caused by breathing motion in the estimated dose …

Oncolytic Virus Therapy For The Treatment Of Metastatic Ovarian Cancer, Jessica Tong

Electronic Thesis and Dissertation Repository

The management of patients with epithelial ovarian cancer (EOC) faces two major challenges which standard treatments fail to effectively address: 1) Diffuse metastasis as a consequence of late stage diagnosis and 2) intra-tumoral heterogeneity, which fuels tumor evolution and drives the acquisition of chemotherapeutic resistance. In this thesis, we tested new therapeutic strategies using a 3-dimensional in vitro spheroid culture model that mimics key steps of epithelial ovarian cancer metastasis; and another model that mimics both temporal and cellular heterogeneity by establishing multiple cell lines from a single patient over the course of disease progression. Using these models, we investigated …