How Does PRLT Work? 

The metastatic prostate cancer produces a Prostate-Specific Membrane Antigen (PSMA) ligand. Ligands are small molecules that transmit signals in between or within cells. The ligand is important because it facilitates the binding to cellular proteins that become receptors that absorb an isotope.  

For therapy, the PSMA ligand is attached to the radioisotope Lutetium-177 and infused into the body. The PSMA that is part of the prostate cancer tumors acts like a homing beacon attracting the radioisotope attached to the PSMA ligand which is then drawn into the tumor. The end result is the death of the tumor. 

The more aggressive the tumor tissue the more PSMA is produced. The presence of this ligand in the tumor can be used for both diagnostic and therapeutic purposes.  

For diagnostic purposes, the PSMA ligand is attached to a radioisotope tracer, Gallium-68, and infused into the body. The PSMA that is part of the prostate cancer tumors acts like a homing beacon attracting the radioisotope tracer attached to the PSMA ligand which is then drawn into the tumor. The end result is the imaging of a tumor when scanned with a PET scanner. 

This is a simplistic explanation, of course.