The FDA has approved floretyrosine F18 (Pixclara, Telix Pharmaceuticals), making it the first FET-PET imaging agent approved in the United States for glioma. The intravenous PET agent is designed to help clinicians differentiate recurrent or progressive glioma from treatment-related changes — a distinction that's often difficult to make with conventional MRI alone. It's approved for use alongside other diagnostic evaluations in adults and children aged 1 month and older.

The drug works by leveraging floretyrosine, an amino acid derivative that's preferentially taken up by transporters overexpressed in glioma cells. Paired with the radioisotope fluorine-18, it becomes detectable via PET imaging. FET-PET has already been widely used in Europe for glioma assessment, and the National Comprehensive Cancer Network recognizes amino acid PET — including FET-PET — as enhancing diagnostic performance when combined with MRI.

By the Numbers:

• Approval based on two studies involving 381 patients aged 5–85 years
• FET-PET readers agreed with expert panels on disease-related changes 66%–83% of the time
• Agreement on treatment-related changes: 48%–64%
• Most common adverse event: headache, occurring in just 0.5% of patients

Why it matters: Distinguishing tumor recurrence from treatment effects — such as radiation necrosis — is one of neuro-oncology's toughest challenges. Having an FDA-approved PET tool specifically for this purpose could meaningfully improve clinical decision-making and reduce unnecessary interventions for glioma patients.