Table 5.
SPECT imaging-based cell tracking methods.
| General Detection Limit/cells [98] | Labeling strategy | Labeling agent | Availability | Clinical approval | Applicable cell types | Labeling efficiency | Cell viability | Efflux from cells |
|---|---|---|---|---|---|---|---|---|
| ~105 | direct | 111In-oxine | Clinical | Yes | circulating progenitor cells [100] | 10–60% | 78–100% | NA |
| BM MSC [99] | 36–53% | >99% | NA | |||||
| White blood cell [101] | NA | NA | NA | |||||
| direct | 111In-tropolone | non-clinical (house-made) | No | canine bone marrow MSC [126] | 80% (0.14 Bq/cell) | 100% (compared with unlabeled cells) | NA | |
| canine bone marrow mononuclear cell and bone marrow stromal cells [127] | < ca. 60% | normal viability and proliferation | NA | |||||
| canine bone marrow stromal cell (BMSC) [128] | BMSC: 92% (0.105 Bq/cell.) | BMSC: 93% after labeling | 111In biologic T1/2 = 14.1 days | |||||
| bone marrow mesenchymal stem cells [129] | 66 ± 5% (38Bq/cell) | viability: equal proliferation: decrease |
retention: 85.3% at 1 h 45.1% at 48 h |
|||||
| indirect | 99mTc-pertechnetate | Clinical | Yes | NIS-expressing adenovirus-transfected canine stem cells [130] | NA | NA | NA | |
| direct | 99mTc-HMPAO | Clinical | Yes | CD34+ cells (Peripheral Blood Bone Marrow Cell) [103] | NA | NA | NA | |
| Stromal vascular factor (MSC) [102] | 30–40% (1 × 10ˆ7 cells) | no apoptosis or necrosis induction; may induce reactive oxygen species (ROSs) | NA | |||||
| White blood cell [104] | 40–80% | NA | <10% for first 1h |