Table 1.
Expression of somatostatin receptor subtypes in PGL and respective affinity profiles of radiolabeled somatostatin agonists.
| SST1 | SST2 | SST3 | SST4 | SST5 | |
|---|---|---|---|---|---|
| % of PGLs with strong overexpression of SSTs | 20% | 80% | − | − | 5% |
| Native SS-28 | +++ | +++ | +++ | +++ | +++ |
| Octreotide (OC) | − | +++ | + | − | ++ |
| [111In]-DTPA-OC (Octreoscan) | − | ++ | + | − | + |
| [68Ga]-DOTA-TOC | − | ++++ | +/− | − | ++ |
| [68Ga]-DOTA-TATE | − | ++++ | − | + | +/− |
| [111In]-DOTA-NOC | − | ++++ | ++ | + | +++ |
SS-28: Native somatostatin (SRIF28)
Affinity (IC50, nM): <5++++, 5 − <40 = +++, 40 − <100 = ++, 100 − <300 = +, 300−<1000 = +/−, ≥1000 = −.