Fluoroethyltyrosine for the Evaluation of Intracranial Neoplasm

Inclusion Criteria:

* Presence or suspicion of intracranial neoplasm in two populations:

  * Population 1: Participants after primary treatment (radiation therapy and/or surgery) with suspicion of recurrence on MRI.
  * Three sub-populations will be considered:

    * Recurrent metastatic lesions.
    * Recurrent high-grade gliomas (Grades 3 and 4).
    * Recurrent low-grade gliomas (Grade 2).
  * Population 2: Participants prior to primary treatment with planned biopsy or surgical resection.
* Age \> 3 years.

Participants in other clinical trials will be eligible for this study including patients undergoing surgery guided by 5-aminolevulinic acid.

Exclusion Criteria:

* Participants with known incompatibility to PET or Computerized tomography (CT)/magnetic resonance imaging (MRI) scans.
* Participants unlikely to comply with study procedures, restrictions and requirements and judged by the Investigator to be unsuitable for study participation.

  * Sedation or anesthesia can be used for participants who cannot tolerate the exam.