Colleen Bailey

Administrative Assistant: Lorelie Lacson
T: (416) 480-4619
Email Lorelie Lacson

At A Glance

• MRI biomarkers for predicting and monitoring cancer therapy response
• MRI methods and biophysical models to relate tumour microenvironment to MRI signal
• Diseases studied include breast cancer, prostate cancer and glioblastoma
• We collaborate extensively with other labs, clinicians, and clinician scientists

Short Bio

Colleen Bailey is a Scientist at Sunnybrook Research Institute and the Odette Cancer Centre, and Assistant Professor in the Dept. of Medical Biophysics at the University of Toronto. Dr. Bailey was a postdoctoral fellow at University College London working on diffusion MRI methods for breast cancer imaging in the laboratory of Dr. David Hawkes, followed by a second post-doc at UCL in the laboratory of Dr. Eleftheria Panagiotaki focusing on prostate cancer. Dr. Bailey earned a Ph.D. in Medical Biophysics at the University of Toronto. Before that, she completed a B.Sc. in Biophysics at the University of Guelph.

Dr. Bailey’s main areas of research are the development of diffusion MRI techniques and analysis methods for examining tumour microstructure, microscopic heterogeneity and its relationship to cancer treatment response.

Research Synopsis

Validation of microstructure models of diffusion signal using histology. In Eleftheria Panagiotaki’s and David Hawkes’s labs, I used mathematical models to describe diffusion MRI signal in terms of vascular, cellular and extracellular components. The aim was to characterize tumours with more biologically relevant parameters and make diffusion-based MRI biomarkers more specific. This work has been used to characterize prostate and breast cancers as well as bone metastases. It includes histological validation using patient-specific 3-D-printed molds and image registration.

Diffusion anisotropy in stromal regions of breast and prostate. Diffusion MRI measurements in cancer have focused on associations between the signal attenuation and cell density. However, changes in anisotropy (directional differences) have also been observed in breast and prostate tissue, but their origin and importance remains largely unknown. I scanned breast and prostate samples ex vivo, demonstrating that anisotropy existed in the absence of ductal structures and may be related to patterns of collagen in the stroma that have been implicated in cancer invasion. These directional diffusion patterns are difficult to detect with conventional in vivo methods and I am therefore developing new methods to explore anisotropy in the clinical setting.

MRI markers of apoptotic cell death. MRI shows anatomical features, but the signal intensity has a complex relationship with microscopic and cellular characteristics of the tissue. I developed a method using conventional contrast agents, T1- and T2-sensitive MRI sequences and a mathematical model to estimate the water exchange across the cell membrane, a parameter that increases during apoptotic cell death. Previous attempts to detect apoptosis with relaxation-based sequences had been unsuccessful or shown changes only at very late stages of cell death. The addition of contrast agents allows early detection and also explains the competing effects that make detection challenging in the absence of contrast. This work was developed in vitro and then translated to clinic, where it predicted the eventual tumour volume decrease following treatment.

Recent Publications

• Bailey C, Collins DJ, Tunariu N, Orton MR, Morgan VA, Feiweier T, Hawkes DJ, Leach MO, Alexander DC, Panagiotaki E. Microstructure Characterization of Bone Metastases from Prostate Cancer with Diffusion MRI: Preliminary Findings. Frontiers in Oncology. 2018. 8: 26.
• Bourne RM*, Bailey C*, Johnston EW, Pye H, Heavey S, Whitaker H, Siow B, Freeman A, Shaw GL, Sridhar A, Mertzanidou T, Hawkes DJ, Alexander DC, Punwani S, Panagiotaki E. Apparatus for histological validation of in vivo and ex vivo magnetic resonance imaging of the human prostate. Frontiers in Oncology. 2017. 7: 47.
• Bailey C, Siow B, Panagiotaki E, Hipwell JH, Mertanidou T, Owen J, Gazinska P, Pinder SE, Alexander DC, Hawkes DJ. Microstructure models for diffusion MRI in breast cancer and surrounding stroma: an ex vivo study. NMR in Biomedicine. 2016. 30: e3679.
• Bailey C, Moosvi F, Stanisz GJ. Mapping water exchange rates in rat tumour xenografts using the late-stage uptake following bolus injections of contrast agent. Magnetic Resonance in Medicine. 2014. 71: 1874-1887.
• Bailey C, Desmond KL, Czarnota GJ, Stanisz GJ. Quantitative Magnetization Transfer Studies of Apoptotic Cell Death. Magnetic Resonance in Medicine. 2011. 66: 264-269.