Determining the extent of tumor resection at surgical planning with ¹⁸F-fluciclovine PET/CT in patients with suspected glioma. Multicenter phase III trials

Objective

Glioma is the most common type of central nervous system tumor reported worldwide. Current imaging technologies have limitations in the diagnosis and assessment of glioma. The present study aimed to confirm the diagnostic efficacy and safety of anti-1-amino-3-[¹⁸F]fluorocyclobutane carboxylic acid (¹⁸F-fluciclovine; anti-[¹⁸F]FACBC) as a radiotracer for patients undergoing combined positron emission tomography and computed tomography (PET/CT) for suspected glioma.

Methods

Combined data from two multicenter, open-label phase III clinical trials were evaluated for this study. The two trials enrolled patients with suspected high- or low-grade glioma on the basis of clinical symptoms, clinical course, and magnetic resonance imaging findings, and who were scheduled for tumor resection surgery. Patients fasted for ≥ 4 h and received 2 mL of ¹⁸F-fluciclovine (radioactivity dose 78.3-297.0 MBq), followed by a 10-min PET scan 10-50 min after injection. The primary efficacy endpoint was the positive predictive value (PPV) of the gadolinium contrast-enhanced T1-weighted image negative [Gd (-)] and ¹⁸F-fluciclovine PET-positive [PET (+)] area of the scans, using the histopathological diagnosis of the tissue sampled from that area as the standard of truth. All adverse events reported during the study were recorded for safety analysis.

Results

A total of 45 patients aged 23-89 years underwent ¹⁸F-fluciclovine PET; 31/45 patients (68.9%) were male, and 30/45 patients (66.7%) were suspected to have high-grade glioma. The PPV of ¹⁸F-fluciclovine PET in the Gd (-) PET (+) area was 88.0% (22/25 areas, 95% confidence interval: 70.0-95.8). The extent of planned tumor resection was modified in 47.2% (17/36 cases) after ¹⁸F-fluciclovine PET scan, with an extension of area in 30.6% (11/36 cases) and reduction in 16.7% (6/36 cases). Furthermore, tissue samples collected from PET (+) areas tended to have a higher malignancy grade compared with those from PET (-) areas. Overall, ¹⁸F-fluciclovine was well tolerated.

Conclusion

¹⁸F-fluciclovine PET/CT is useful for determining the extent of tumor resection at surgical planning, and may serve as a safe and effective diagnostic tool for patients with suspected glioma.

Trial Registration

These trials were registered in the Japan Pharmaceutical Information Center Clinical Trials Information (JapicCTI-152986, JapicCTI-152985). (author)