What are the differences between Targeted Radionuclide Therapy, Radiotheranostics and Targeted Alpha Therapy, the differences?
Targeted Radionuclide Therapy, Radiotheranostics and Targeted Alpha Therapy, 3 terms that are constantly confused, even by people inside the field, but they have different meanings.
- Targeted Radionuclide Therapy (TRT)
Any radiotherapy with a radionuclide guided by a targeting molecule, that targets specific tumors.
The targeting molecule can be a peptide, an antibody, a nanobody, a small molecule or any other vector that binds selectively to a receptor or antigen overexpressed on diseased cells.
The radionuclide is the therapeutic payload that delivers the radiation to tumorous lesions to destroy or damage the cells.
- Radiotheranostics
Under TRT, radiotheranostics have a specific pair strategy, with the same targeting molecule bonded to two different radionuclides, one for diagnosis and another for therapy.
First, radiotheranostics travel through the body to the targeted cells for diagnosis. When the radiation starts, it directly works to damage or destroy the targeted cells at the same time.
It can be beta- or alpha-emitting radionuclides.
- Targeted Alpha Therapy (TAT)
Under TRT, TAT use alpha-emitting radionuclides only as therapeutic payload.
TAT can be used within a theranostic approach, pairing an alpha-emitting therapeutic isotope with a diagnostic partner on the same targeting molecule. Or it can be deployed as a standalone TRT modality.
It’s the most precise TRT as alpha emitters travel 50 to 80 micrometres, by depositing energy at approximately 20 times the LET of beta-emitters.
Sources:
- National Cancer Institue - NCI dictionaries. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/targeted-radionuclide-therapy
- Radiotheranostics - Precision Medicine in Nuclear Medicine and Molecular Imaging. Nanotheranostics. 2022 Jan 1;6(1):103–117. doi: 10.7150/ntno.64141 https://pmc.ncbi.nlm.nih.gov/articles/PMC8671964/