Theranostics

Theranostics Lu 177 and Ac 225

Lutetium-177

This treatment procedure is closely related to the PET/CT PSMA Gallium-68 diagnostic as it uses the very same chemical process except that the Gallium-68, which is useful for diagnosis, is replaced by Lutetium-177, which is therapeutic – killing the cancerous cells where they are positioned in the body with suitable radiation.

Fortuitously, the Lutetium-177 gives off a second radiation which is diagnostic in nature. This means that a Gamma Camera can be used to confirm that the Lutetium-177 has been delivered to exactly the right places in the body.

It was formally announced, as was PET/CT PSMA Gallium-68, in June 2015 and has been gaining ground ever since.

It is used generally in Stage 4 of the Prostate Cancer disease and would be chosen, if indicated, instead of Chemotherapy, or, indeed, in conjunction with Chemotherapy.

You may see the term “Theranostics” associated with this procedure. The word Theranostics is formed from “Therapeutics” and “Diagnostics” to reflect the dual nature of this approach.

This procedure is definitely a treatment modality to “keep an eye on”. I am personally interested in this approach.

Actinium-225

Research is currently underway looking at Ac225 as the radioactive nuclide to provide the therapeutic effect. This nuclide is more powerful than Lu177 at killing cancerous cells.

There is some limited collateral damage done by both the Lu177 and Ac225 procedures and it is more pronounced with the use of Ac225. There is a trade-off here that is currently under trialled investigation.

Both Lu177 and Ac225 seem to have great promise, and could replace Chemotherapy as the treatment of choice for metastases.

A brief history can be found along with that of PET/CT PSMA Gallium-68.

The following PCRI video discusses the use of Theranostics for Bone [and Lymph Node] Metastatic disease.