Clinical Translation of a Quantitative Oxygen Sensor for HDR Cervical Cancer Brachytherapy

Abstract

Hypoxia is a poor prognostic factor in multiple tumor types. Hypoxic tumors are more resistant to radiation and chemotherapy and are more likely to develop distant metastases. Radiation resistance is of particular interest in cervical cancer, as baseline tumor hypoxia has been shown to be prognostic for local failure and survival in patients treated with primary radiotherapy.1 In vivo studies have shown that radiation resistance may be overcome by increasing the delivered radiation dose by a factor of 2-3. MR-based HDR brachytherapy is well suited for localized dose escalation in hypoxic tumor sub-volumes given the ability to modulate the dose distribution while respecting normal tissue constraints. Currently available clinical techniques for measuring hypoxia are qualitative and limited by poor sensitivity. Meaningful modulation of dose distribution will require an MRI-compatible quantitative oxygen sensor capable of repeated measurements throughout the duration of treatment.