Author: Jonah Nick
Topic: Cancer Theranostics
Two key developments in the search for an umbrella cancer treatment are prognosis and targeted therapy. Radiopharmaceuticals have the potential to make comprehensive treatment a reality due to the unique characteristics of radioactive compounds known as radionuclides. Radionuclides have both diagnostic and therapeutic (theranostic) applications, allowing tandem use for imaging and radiation therapy. Through radioactive decay, these nuclides can inflict irreparable damage to targeted cells, making them less invasive and more precise than current alternatives. Additionally, they can attack many diseases that have not demonstrated a sufficient response to current therapies.
What are theranostics?
A theranostic is a drug in which two chemically similar or identical molecules are paired to provide imaging diagnostics and irradiation therapeutic effects. Since it was coined by John Funkhouser, the term has been used to describe an emerging field that integrates diagnosis and targeted therapy as a means of personalizing disease treatment. Over the past few decades, radiopharmaceuticals have been widely used as diagnostic tools through imaging techniques including PET and SPECT scans. These scans use radioactive tracers to construct three-dimensional organ models that can represent complex physiological functions. On the other hand, while still acting as radiotracers, various radionuclides can be employed with more precision to provide a therapeutic effect that minimizes damage to healthy tissue. The theranostic capabilities of radionuclides continue to grow as researchers continue to explore sources of new radioisotopes.
What is targeted therapy?
Targeted therapy is a process by which a tissue that obstructs normal function, such as a tumor, can be attacked without sacrificing nearby healthy tissue. This process occurs when a radionuclide gets attached to a targeting molecule, which can then attach to a protein unique to the tumor tissue. Once anchored, the radionuclide can directly degrade the cancerous region without damaging adjacent tissues. Research in this field remains active, aiming to broaden both the range of effective radionuclides and the variety of diseases they can treat.
What diseases has this been effective for?
Several conditions have been effectively diagnosed and even alleviated by radiopharmaceuticals, including thyroid cancer, prostate cancer, neuroendocrine tumor, pheochromocytoma, lung cancer, and malignant bone metastases. One promising example involves prostate-specific membrane antigen (PSMA)-targeted radiopharmaceuticals. These have demonstrated immense potential in serving as theranostics in metastatic prostate cancer management, with radioisotope probes 68Ga and 177Lu being noteworthy in terms of their efficacy.
What is the future outlook?
Nuclear medicine in the form of radiopharmaceuticals is still considered a relatively new frontier, though like nuclear energy, it holds immense potential. Nevertheless, expanding upon current theranostics and treatable diseases will take time. This is partly due to the requirement of additional stages that go beyond those typical of traditional drug development. The inherent design and synthesis of radionuclides are also challenging due to experimental complexities and rigid safety protocols; these contribute to the preclinical trial backend that is unique to radionuclides. Still, the outlook remains optimistic as momentum continues to shift favorably toward a nuclear medicine revolution that could transform clinical practice in the context of disease.
References
“Lipid Metabolism and Cardiovascular Disease: Current and Future Directions.” PMC, PubMed Central, National Institutes of Health, 2021, https://pmc.ncbi.nlm.nih.gov/articles/PMC10768149/.
Zhang, Y., et al. “Biological and Clinical Implications of the Spinal Cord and Peripheral Nerve Pathology in Multiple Sclerosis.” Nature Reviews Rheumatology, vol. 20, no. 4, 2024, pp. 233-244. Nature, https://www.nature.com/articles/s41392-024-02041-6.
Liu, Y., et al. “Flexible and Biocompatible Nanomaterials for Wearable Electronics and Soft Robots.” ACS Applied Materials & Interfaces, vol. 6, no. 19, 2014, pp. 15213-15226. American Chemical Society, https://pubs.acs.org/doi/full/10.1021/acsami.4c20602.