Preoperative imaging of glioblastoma patients using hyperpolarized C pyruvate: Potential role in clinical decision making.

Background: Glioblastoma remains incurable despite treatment with surgery, radiation therapy, and cytotoxic chemotherapy, prompting the search for a metabolic pathway unique to glioblastoma cells.C MR spectroscopic imaging with hyperpolarized pyruvate can demonstrate alterations in pyruvate metabolism in these tumors.

Methods: Three patients with diagnostic MRI suggestive of a glioblastoma were scanned at 3 T 1-2 days prior to tumor resection using a C/H dual-frequency RF coil and a C/H-integrated MR protocol, which consists of a series of H MR sequences (T FLAIR, arterial spin labeling and contrast-enhanced [CE] T) and C spectroscopic imaging with hyperpolarized [1-C]pyruvate. Dynamic spiral chemical shift imaging was used for C data acquisition. Surgical navigation was used to correlate the locations of tissue samples submitted for histology with the changes seen on the diagnostic MR scans and the C spectroscopic images.

Results: Each tumor was histologically confirmed to be a WHO grade IV glioblastoma with isocitrate dehydrogenase wild type. Total hyperpolarized C signals detected near the tumor mass reflected altered tissue perfusion near the tumor. For each tumor, a hyperintense [1-C]lactate signal was detected both within CE and T-FLAIR regions on the H diagnostic images ( = .008). [C]bicarbonate signal was maintained or decreased in the lesion but the observation was not significant ( = .3).

Conclusions: Prior to surgical resection, C MR spectroscopic imaging with hyperpolarized pyruvate reveals increased lactate production in regions of histologically confirmed glioblastoma.