2D 1H sLASER long-TE and 3D 31P chemical shift imaging at 3T for monitoring fasting-induced changes in brain tumor tissue

Motivation: Emerging evidence suggests that fasting could play a key role in cancer treatment, however, its metabolic effects on gliomas require further investigation. Goal(s): To design a 1H/31P MRSI protocol for non-invasive metabolic monitoring of fasting-induced cerebral changes at individual patient/tumor level, and to assess its technical reliability/reproducibility. Approach: Twenty-two patients with MRI-suspected glioma were measured with the protocol at baseline and after 72-hour-fasting. Results: Ketone body accumulation in solid tumors and necrosis was observed after 72-hour-fasting and validated via ex-vivo high-resolution NMR. This may result from neovascularization, the blood-brain barrier compromise, and lack of ketone body consumption in necrosis. Impact: We report on the validation of a dedicated, multinuclear MRSI protocol with fully automated multiparametric segmentation of glioma sub-regions for monitoring cerebral, fasting-induced changes in patients with glioma.