All theranostics involve the same five components:
Radioligand Target: The specificity
and abundance of the target on the cancer cells determine the effectiveness
of detection on PET scans and the success of RLT. A highly specific target
reduces side effects, while a less specific target increases the likelihood
of side effects. For example, PSMA is a common target for prostate cancer but
is also found in salivary glands, leading to potential side effects like dry
mouth when targeting prostate cancer.
Radioisotope: A radioactive atom
undergoing radiation decay to become stable and non-radioactive. Depending
on the type of energy released during decay, it can be used for imaging or
treating cancer.
Ligand: A molecule that binds to
a radioisotope and delivers it to a specific site on the surface of a cancer
cell, known as the target. The ligand can be either an antibody or a small
molecule.
Linker: This component connects the
ligand to the radioisotope, similar to a hitch on a truck. It is crucial for
the stability of the radioligand therapy (RLT) while in circulation, preventing
the premature release of the radioisotope before it reaches the target and
ensuring efficient release at the target site.
Chelator: This securely holds the
radioisotope in place, akin to strap tie-downs on a cargo truck. It is vital
to prevent the premature release of the radioisotope and to determine its release
at the target site.