Table 1.
Head-to-head comparison of 18F (prosthetic-based) and BFCA chelated radio-metal-based tracers targeting PSMA for imaging prostate carcinoma.
| Characteristics | 18F (Prosthetic-Based) Tracers | Radio-Metal-Based Tracers Using BFCA |
|---|---|---|
| Physical, Chemical and Radio-biological aspects | ||
| Source | Cyclotron | 68Ge/68Ga Generators |
| Radiochemistry | Relatively lower energy positron causing less image noise. Higher positron yield. |
High energy positron causing increased image noise. Low positron yield. |
| Radiation Safety | Relatively less radiation exposure | Higher radiation exposure |
| Synthesis | Time consuming and challenging | Relatively simpler and less time consuming |
| Yield | Remains stable | Decreases as the generator gets old |
| Installation and maintenance | More technically demanding and costly | Less technically demanding and relatively less costly |
| Pharmacokinetic properties | ||
| Half-life (t1/2) | Longer half-life: permits transportation, longer uptake time and delayed imaging | Shorter half-life mandates an in-house generator and cannot be transported |
| Binding affinity | Relatively lesser | Strong binding affinity |
| Excretion | Hepatobiliary (PSMA 1007) and Urinary (DCFPyL) PSMA 1007 is better for imaging pelvic disease |
Predominately urinary smaller pelvic lesions may remain obscured due to high urinary activity |
| Detections Rates | ||
| Overall for putative sites of disease on a per-patient-based analysis | Higher detection efficiency (DCFPyL > 1007) | Relatively lesser than 18F-based agents |
| According to PSA levels | Demonstrates better statistics at lower level of PSA | Demonstrates relatively poor statistics at lower PSA but has similar detection rates at PSA > 1.0 to 2.0 ng/ml |
| In accordance with histopathology and Gleason score | No significant correlation with Gleason score/grade | Correlates well with Gleason score/grade |
| Theranostic potential | ||
| 177Lu/225Ac-based agents | No known theranostic pair in widespread clinical use. 177Lu-CTT 1403 is theranostic pair of 18F-CTT 1057 and is in pre-clinical trials |
177Lu-PSMA-617 is a good theranostic pair which has widespread clinical use with good results and has recently received FDA approval |
| Tracers | PSMA-1007, PSMA-DCFBC, PSMA-DCFPyL | PSMA-HBED-CC (PSMA-11), PSMA-617, PSMA- I and T. |