Table 3 Teratoma imaging with non-18F-FDG radiotracers *1
Radiotracer class [Name of the radiotracer] | Research aim | Sample size | Study type | Encouraging results? | First author (Reference) |
|---|---|---|---|---|---|
Integrins  - αvβ3 [99mTc-HYNIC-RGD] | Mature teratoma vs. necrosis | 20 rats | Preclinical animal study | Yes, for αvβ3 imaging No, for FDG | Aide [110] |
Integrins  - αvβ3 [99mTc-3PRGD2] | Detection of hiPSC-derived teratoma | 4 rats | Preclinical animal study | Yes, for αvβ3 imaging No, for FDG | Li [67] |
Integrins  αvβ3 [64Cu-DOTA-RGD4] | In vivo visualization of teratoma formation | 12 rats | Preclinical animal study | Yes, for αvβ3 imaging No, for FDG and FLT | Cao [111] |
Integrins  - αvβ3 [99mTc-HYNIC-RGD] | Biodistribution and imaging of αvβ3-negative and positive tumors | 4 rats | Preclinical animal study | Equivocal, no definite conclusion regarding the main reason for integrin uptake (i.e., vasculature vs. cellular expression) | Bohn [112] |
Radioiodine  - 124I | In vivo visualization of teratoma formation | 9 rats | Preclinical animal study | Yes, highly specific; Tracer uptake correlated with teratoma weight and washed out with perchlorate | Lehner [113] |
18F-FLT [39-deoxy-39–18 F-fluorothymidine] | Added value of FLT on top of FDG PET | 11 patients (2 teratoma cases) | Case series | No, FDG and FLT were both falsely negative. | Pfannenberg [63] |
67Ga-Citrate | Detection rates in various GU malignancies | 11 teratoma cases (16 lesions) | Retrospective clinical cases | No, low detection rate (25%) | Sauerbrunn [72] |
PSMA:  - 68Ga-PSMA/177Lu-PSMA | Single dose of 177Lu-PSMA RLT in a case of refractory mixed GCT | 1 patient | Case report | No, rise in AFP and evidence of tumoral progression in the hepatic lesion despite sufficient PSMA uptake | Simsek [66] *2 |
FAPi:  - 68Ga-FAPi-04 | Comparison with FDG uptake | 1 patient | Case report | Equivocal, FAPI (moderate uptake) vs. FDG (low uptake) | Kaplan [1] *3 |
18F-Fluciclovine | Detection of residual disease/teratoma | 10 patients (5 teratoma cases) | Case series | No, low detection rate (40%) in the teratoma subgroup | Woldu [64] |