Combined use of F-18 fluorocholine positron emission tomography and magnetic resonance spectroscopy for brain tumor evaluation

Background. Choline metabolism is often abnormal in malignant brain tumors. Methods. Brain positron emission tomography (PET) imaging with F-18 fluorocholine (FCH) was performed on 2 patients with intracranial lesions suspected to be high-grade malignant gliomas on the basis of magnetic resonance (MR) imaging and multivoxel 1H-MR spectroscopic imaging (MRSI) findings. Standardized uptake value (SUV) measurements on PET were compared with measurements of choline/creatine metabolite ratio on MRSI in corresponding regions. Brain biopsy revealed glioblastoma multiforme (GBM) in one case and demyelinating disease in the other. Results. In the case of GBM, the tumor demonstrated increased FCH uptake on PET. The mean and maximum SUV in areas of the tumor correlated with regional choline/creatine ratio measurements (r = 0.76, P <.001; r = 0.83, P <.001, respectively). In the case of tumefactive demyelinating lesions, the lesion demonstrated low FCH uptake, which did not correlate with choline/creatine ratio measurements. Conclusions. Assessments of choline metabolism may aid in evaluating intracranial mass lesions.