Table I.
PET-radiopharmaceuticals employed for PET/CT studies in patients with orbital and ocular tumors.
| Feature | 18F-FDG | 18F-NaF | 68Ga-DOTA- compounds | 18F-fluorocholine (18F-FCH) | 11C-methionine Methyl (11C-MET) | Alpha-[11C] -L-Tryptophan (11C-AMT) |
|---|---|---|---|---|---|---|
| Half-life | 110 min | 110 min | 68 min | 110 min | 20 min | 20 min |
| Synthesis requirements | Cyclotron | Cyclotron | In-house generator | Cyclotron | Cyclotron | Cyclotron |
| Molecular target | Metabolic activity | Bone remodeling | SSTRs cell surface overexpression | Cell membrane synthesis | Amino acid transport | Tryptophan metabolism |
| Orbital or ocular tumor | Lymphoma, uveal melanoma, retinoblastoma conjunctival melanoma, sebaceous carcinoma, squamous cell carcinoma, optic nerve glioma, ocular and orbital metastases, inflammatory orbital pseudotumor, fibrous dysplasia | Fibrous dysplasia | Ocular and orbital metastases from neuroendocrine tumors (NETs) | Optic nerve glioma |
SSTR, somatostatin receptor; 18F-FDG, 18fluoride-fludeoxyglucose; 18F-NaF, 18F-sodium fluoride.