This Phase II clinical trial, sponsored by **Primo Biotechnology Co., Ltd.**, evaluates the clinical benefit of **$^{18}$F-FET PET/CT** in diagnosing glioma. The study aims to compare the diagnostic performance of $^{18}$F-FET PET imaging against traditional brain MRI, using surgical histopathology as the gold standard for verification.

**Study Design and Participants** This is a single-center, open-label, non-randomized trial conducted in Taiwan. The study will enroll a total of **36 participants**, consisting of 6 healthy volunteers (to assess biodistribution and dosimetry) and 30 patients with suspected primary gliomas scheduled for surgery.

**Methodology** The test drug, $^{18}$F-FET, is a radiopharmaceutical that targets large neutral amino acid transporters (LAT). It is administered via intravenous injection at a dosage of 3MBq/kgw.

• **Volunteers** undergo PET/CT scans immediately and every 20 minutes for 90 minutes.
• **Patients** receive a static PET scan 40-50 minutes post-injection.

**Endpoints and Safety**

• **Primary Endpoint:** Diagnostic sensitivity compared to MRI.
• **Secondary Endpoints:** Specificity, PPV, NPV, tumor-to-background ratios (TBR), and safety (adverse events/vital signs).
• **Radiation Safety:** The total estimated radiation exposure is **7.63 mSv**, which is well below the international safety threshold of 100 mSv.

**Conclusion** The trial seeks to establish $^{18}$F-FET PET/CT as a safe and effective diagnostic tool for the pre-surgical assessment of gliomas, potentially providing higher sensitivity and more accurate lesion detection than conventional MRI in Asian cancer patients.

• Inclusion criteria： For health volunteers

  1. Participants must be ≥ 20 years old.
  2. Participants are alert and oriented, and able to independently sign ICF. For glioma patients
  1. Participants must be ≥ 20 years old.
  2. Participants with suspected primary gliomas scheduled for surgery.
  3. Participants are alert and oriented, and able to independently sign ICF.

• Exclusion criteria：

  1. Liver dysfunction within the past 6 months (e.g., AST/ALT ratio > 2, total bilirubin > 1.5 mg/dL).
  2. Chronic kidney disease stage 4 (eGFR < 30 mL/min/1.73 m2) within the last 6 months.
  3. Acute kidney injury within the past 6 months.
  4. Allergic to any radiopharmaceuticals or contrast agents.
  5. Restlessness or inability to lie in a cast for 30 to 60 minutes.
  6. Women who are pregnant, lactating, or planning pregnancy during the study period or before screening.
  7. PI deemed the participant unsuitable.
  8. The patient is not able to understand the treatment options.