Investigating the Predictive Power of Oxygen-Enhanced MRI to Assess Radio-sensitivity in a Murine Model of Oral Carcinoma

Motivation: Tumour hypoxia is associated with radioresistance and is a negative factor in the prognosis of oral cavity squamous cell carcinoma. Non-invasive methods to rapidly quantify the extent and heterogeneity of tumour hypoxia would offer clinical benefit in treatment planning. Goal(s): To assess the utility of oxygen-enhanced (OE-) MRI to image hypoxia and provide predictive imaging biomarkers of radiation response. Approach: OE-MRI was performed in murine oral carcinoma allografts prior to 8Gy irradiation, and relationships with subsequent overall tumour response sought. Results: Tumours exhibiting voxels with a marked hyperoxia-induced reduction in R2* yet negligible ΔR1 were more radiosensitive. Impact: OE-MRI revealed extensive hypoxia in murine oral carcinoma allografts, and have the potential to predict tumour radiosensitivity based on the combined degree of hypoxia and haemodynamic vasculature.