Evaluation of 18F-Fluciclovine Positron Emission Tomography - Magnetic Resonance Imaging (PET-MRI) in LGG

Inclusion criteria

• LGG including the brainstem and supratentorial only (WHO grade I-II), confirmed by biopsy unless in NF1 participants with classic appearance.
• Participants must have evaluable disease (1x1 cm tumor on MRI)
• Scheduled to receive systemic therapy for LGG
• Performance Score: Karnofsky ≥ 50 for participants > 16 years of age and Lansky ≥ 50 for participants ≤ 16 years of age. Participants who are unable to walk because of paralysis, but who are up in a wheelchair, will be considered ambulatory for the purpose of assessing the performance score.
• Age: Participants must be ≥ 1 years but ≤21 years of age at registration
• Being on a treatment regimen does not exclude a subject from enrollment.

Exclusion criteria

• Inability to tolerate imaging procedures in the opinion of an investigator or treating physician
• Pregnant participants
• Participants who weigh less than 8 kg.
• Participants who cannot avoid contact with a pregnant woman or infant for at least 12 hours following injection.
• Participants with a history of abnormal kidney function or creatinine >= CTCAE v5.0 grade 2 at time of study registration.
• Participants with primary tumors of the spinal cord.