FCH PET in glioma: preliminary results

Introduction: FCH is a relatively new PET radiotracer in Australia. It has shown promise as an oncologic imaging agent for glioma.We present our preliminary experience with this tracer in glioma. Methods: 7 patients with suspected primary glioma were recruited. All patients were invited to undergo FDG and FCH PET scans after CT ± MRI. All baseline imaging performed prior to biopsy, surgical resection or radiotherapy. Uptake of FDG and FCH assessed using avisual grading scale and SUV. Anatomical localisation was confirmed by visually comparing the PET scans with the corresponding MRI ± CT scans. The student t test was used to evaluate the differences between 18F-FDG and 18F-FCH PET Results: 7 patients (4 men, 3 women, 18–72 years, mean age 43 years) MRI performed in all patients, 5 cases underwent CT scans, and MRS was performed in 4 cases. 3 cases had high-grade primary brain tumours; 2 had grade II gliomas. For 2 cases without histopathology, one was considered a low grade glioma and the other benign epilepsy. No significant difference was found in SUV or Tumour/Background for FCH or FDG between high grade or low grade tumours. Contrast was better for FCH due to very low background. FCH and FDG showed low uptake in the benign epilepsy case. Post-treatment scans showed reduction in FDG and FCH uptake. Conclusion: Preliminary results are encouraging for FCH as a glioma imaging agent. The low background found in normal cerebral structures improves contrast and tumour visualisation compared with FDG.