What if I told you that there is a medication that I can give you IV, which will seek out cancer cells in your body and selectively destroy them? Kill your cancer with minimal effect on your normal organs, so that there are few side effects. This is what theranostics brings to cancer patients. Like millions of “guided missiles,” these specialized radioligand molecules will automatically find their targets. Once at the targeted location, the radioligand emits its cytotoxic radioactive particles destroying nearby cancer cells. In recent years, there has been a real renaissance in nuclear medicine with the development of theranostics. The key is the ability to use imaging techniques like PET/CT with radioisotopes that target a specific receptor that is expressed in a disease state. Then we follow it up with the same tracer/ligand attached to a therapeutic isotope. This very powerful technique has just gotten its start in neuroendocrine tumors and prostate cancer.

These techniques have been in research and development for years in both university and industry settings. We now routinely image patients with neuroendocrine tumors with Ga-68 or Cu-64 DOTATATE PET/CT and then can treat them with Lu-177 DOTATATE taking advantage of somatostatin receptor expression on neuroendocrine tumors. Similarly, we have both Ga-68 or F-18 PSMA PET/CT to image prostate cancer patients and then can treat them with Lu-177 PSMA utilizing PSMA receptor expression on prostate cancer cells. Both agents use Lu-177 which emits beta particles damaging the DNA of nearby cells. These agents had landmark successful multicenter Phase III clinical trials (Netter-1 and Vision) which led to their FDA approval. Now thousands of patents with metastatic disease are eligible for targeted therapy, where there may be too many lesions for conventional external beam radiation therapy, or when chemotherapy or hormonal therapy is failing.

We are now focused on accelerating the development of new diagnostic and therapeutic radiotracer platforms which will allow the identification and treatment of disease in ways not previously possible. This includes developing new theranostic agents which not only use beta emitters, but also use alpha emitting isotopes with the hope of increasing survival and lessening toxicity for cancer patients. An alpha particle is more like a “smart bomb” which does even more damage than the beta particle, but has a shorter path of travel within tissue, making collateral damage to normal tissues even less. This will occur via UCI’s participation in clinical trials, as there is a plethora of these now for theranostic therapies. The key to success here will be a close working relationship between radiology, oncology, and radiation oncology. Strong partnership between the respective departments is the necessary groundwork which will make UCI the premier institution for innovative theranostic clinical trials in Orange County.

World Theranostics Day is March 31^st, which is a celebration to honor Dr. Saul Hertz who conceived, developed, and administered the first radioiodine therapy to a patient on March 31st, 1941, radioiodine effectively being our first theranostic agent. Nuclear Medicine, Molecular Imaging, and Theranostics are quickly evolving fields, with marked developments in precision medicine leading to improved patient care. No question we stand on the shoulders of giants, and it is truly a privilege to be here at UCI to have the opportunity to develop the future of theranostics. We are in the process of establishing two theranostic centers, one at Orange campus in Bldg 20, to open in late 2024 and the other at the Irvine ACC to open in 2025. There is so much yet to be done, and it will be interesting to see how theranostics evolves over the next decade. We at UCI are poised and ready to help shape that future!