Investigating Systemic and Tumour-Specific Fluctuations in Tumour R2* Measurement with Independent Component Analysis and Pulse Oximetry

M. R. Gonalves¹, Simon Walker-Samuel¹, Sean Peter Johnson², Rosamund Barbara Pedley², Mark F. Lythgoe¹

Solid tumours have been found to exhibit fluctuating patterns of hypoxia-reoxygenation, which contribute to resistance to chemotherapy and radiotherapy, as well as being associated with a more aggressive phenotype. We present an Independent Component Analysis (ICA)-based approach to identify the contribution of systemic changes in blood oxygenation on tumour fluctuations and separate them from those which are specific to the tumour. We performed a comparison between two colorectal tumour xenograft models with differing vascular characteristics.