Research

Currently the only definite way to diagnose cancer is by surgically removing tissue samples via biopsy. However, this procedure is invasive and not always possible for monitoring cancer progression. Recent advances in medical imaging play an increasingly promising role in improving clinical data by assisting better detection, staging and treatment planning of cancer.

verdict

Example prostate VERDICT parameter maps (patient with Gleason 3+4, the lesion is in red and in black a benign region). A) T2 weighted image, B)vascular volume fraction index, C) intracellular volume fraction D) extracellular-extravascular space volume fraction E) cell radius F) VERDICT cellularity map

Vascular Extracellular and Restricted DIffusion for Cytometry in Tumours (VERDICT) [1, 2] is a quantitativeMagnetic Resonance Imaging (MRI) tool for assessing tumours based on diffusion imaging. It is designed to estimate features such as cellularity harmlessly avoiding side effects of biopsy like infections and bleeding, thus ideal for monitoring the disease progression. The technique requires a specialist diffusion MRI acquisition protocol. It produces quantitative maps of several informative features of the tumour microenvironment including cellular volume fraction, average cell size, vascular volume fraction. VERDICT was developed initially using xenograft models of colorectal tumours in mice [1]. More recently it has been adapted for use in human prostate cancer assessment [2].

My fellowship leverages VERDICT to develop innovative MRI methods to reveal new non-invasive markers of cancer pathology. In particular, I develop biophysical models of tumour tissue that support non-invasive estimates of key characteristics of tissue architecture including those that currently guide diagnosis, grading, and treatment assignment through classical histology. In contrast to classical histology, such an approach avoids unnecessary interventions like biopsies. Moreover, the models combine with macroscopic imaging to provide maps of histological features over the whole organ, thus evading false-positives from poor biopsy targeting. In contrast to current imaging techniques, the new model-based imaging techniques provide much greater specificity associating contrast with particular tissue changes thus providing much better information on which to assign treatment. The ultimate goal is to enable non-invasive cancer detection, staging and grading entirely through harmless imaging.

  1. Panagiotaki, E., Walker-Samuel, S., Siow, B., Johnson, P., Pedley, R., Lythgow, M. F., & Alexander, D. C. “Non-invasive quantification of solid tumor microstructure with VERDICT MRI”. Cancer Research. 2014.
  2. Panagiotaki, E., Chan, R. W., Dikaios, N., Ahmed, H., Atkinson, D., Punwani, S., Hawkes, D. J., Alexander, D. C. “Microstructural characterisation of normal and malignant human prostate tissue with VERDICT MRI”. Investigative Radiology 50 (4), 218-227 2015
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