Measurement of tissue oxygen saturation and oxygen metabolism in brain tumors using magnetic resonance imaging

Purpose: In vivo tissue oxygen saturation measurement is of great interest in tumor pathology, considering the negative impact of hypoxia on prognosis and the implied possible therapeutic options. The purpose of this study was to apply to various brain tumors a method of tissue oxygen saturation (StO₂) and cerebral metabolic rate of oxygen (CMRO₂) measurement, by magnetic resonance imaging (MRI), using the BOLD effect (Blood Oxygen Level Dependent). Methods: In this prospective monocentric study, 40 patients were included, suffering from primary or secondary brain tumors. Each patient benefited from one or more MRI, with morphological, perfusion and oxygen measurement series. The primary objective was the analysis of StO₂ and CMRO₂ values in different tumor types; secondary objectives were the analysis of peritumoral region and variations before and after radiation therapy. Results: In comparison with the healthy brain hemisphere, StO₂ was higher in all glioblastomas and meningiomas. CMRO₂ was decreased in all tumor types. Two different regions were individualized in peritumoral areas, one of them with evolutionary potential. After radiation therapy, values tended to normalize. Conclusion: This study demonstrated that this MRI protocol was feasible, easy to pursue and reproducible, with promising results, consistent with known literature data and allowing future studies that would include a greater number of patients. (author)