Theranostics

Therapeutics + Diagnostics= Theranostics

Theranostics is a one-two punch against cancer that involves finding cancer cells anywhere in the body and delivering targeted radiation to kill those cells. Positron emission tomography (PET) is used to locate the cancer, followed by an infusion of medicine to destroy it. Because of its precision, theranostics reduces the risk of harming nearby healthy tissues.

Recent medical advances have increased the number of FDA-approved theranostic procedures in the United States. University of Chicago Medicine physicians are leaders in this drive for new theranostics and have contributed to numerous clinical trials and research on these promising treatments. 

What is theranostics?

Theranostics is a two-pronged approach to diagnosing and treating cancers through the use of radiotracers. Radiotracers are compounds made of radiation and chemicals that selectively bind to a specific target in the body. Doctors use a pair of radiotracers that are virtually identical, other than the type of radiation they give off. 

How do theranostic radiotracers work?

A radiotracer consists of two pieces: one half is the biologic side that travels through the blood to bind to a unique, designated target – in this case, a type of cancer cell. The other half is the radioactive component. During the diagnostic scan, that radioactive component emits a low amount of radiation that allows us to take pictures of the cancer cells onto which the radiotracer has latched. During the treatment, the biologic side is almost identical, but the radioactive component is a different, more powerful kind of radiation that kills cancer. 

During both the diagnostic and treatment procedures, the biologic side must bind itself to that precise target on the tumor cells. Because most other healthy cells lack that target, the radiotracers do not attach to them. 

Who is eligible for theranostic procedures?

Today, theranostics is an option available for metastatic disease that fails to respond well to established systemic therapies such as conventional chemotherapy. If those stop working, you may become a candidate for theranostics. We do a PET scan first to see if your tumor can be targeted by the tracers; if the answer is yes and the tumor is widespread, you’re a candidate. If your tumor isn’t widespread, selective treatments such as surgery, external beam radiation or embolization (where the tumor’s blood supply is interrupted by an interventional radiologist) may be more effective. 

What types of cancer can be treated with theranostics?

One of the oldest, tried-and-true theranostics still commonly used today is a pair of radioactive iodine tracers for thyroid cancer. We've performed this procedure successfully for decades and it remains an important part of our tool box for treating thyroid cancer. Unlike other theranostic procedures that are administered intravenously, this one is given as a pill or liquid. 

Modern theranostic medicine uses sophisticated biochemistry to treat cancers such as:  

• Neuroendocrine cancer.  Lu 177 dotatate (Lutathera) has revolutionized the way we treat neuroendocrine tumors, in particular carcinoids. The dotatate targets somatostatin receptors on the tumor cells.
• Prostate cancer. Lu 177 vipivotide tetraxetan PSMA (Pluvicto) treats patients with castration-resistant prostate cancer who have already had androgen receptor pathway inhibition and taxane-based chemotherapy. Patients receive an infusion every six weeks for a total of six treatments. UChicago Medicine is the only hospital in the region to have been involved in the Lu 177 PSMA managed access program prior to its FDA approval. 
• Adult pheochromocytoma and paraganglioma; pediatric neuroblastoma. I131-iobenguane / MIBG (Azedra) is used to treat pheochromocytoma and paraganglioma in adults and a related drug to treat neuroblastoma in children.

What are the benefits of theranostic medicine?

Theranostic treatments in general do not cure cancer, but they do extend the length and quality of life for people who may need other treatment options. Theranostic treatments are well tolerated, so the risks of side effects to patients are usually outweighed by the benefits, including a lessening of symptoms caused by the cancer. 

What are the side effects of theranostic medicine?

Because your body is exposed to radiation – even though this radiation is highly targeted – this can slightly increase your chance of developing other cancers. One common side effect is levels of certain blood cells may decrease somewhat because the treatment can “stun” your bone marrow, where blood cells are made. This is usually temporary. Some patients experience fatigue and gastrointestinal symptoms such as nausea and appetite loss. 

Other side effects are more specific to the therapy. For instance, with PSMA prostate cancer therapy, patients can experience a dry mouth because their salivary glands receive some radiation. We keep an eye on all of these potential side effects. We check your blood counts after each infusion to ensure your blood cells are tolerating the treatment.   

What happens during a theranostic procedure? 

Patients first receive an intravenous injection containing the radiotracer in either their arm or hand. This liquid, chemical compound is administered at our PET Center. It takes approximately an hour for the radiotracer to absorb and bind to cancer cells; you’ll then lie on the PET table as the machine scans your body for cancer cells. 

The scan results will show if there’s cancer and where it is in the body. A nuclear medicine physician will review these images and send a report to your cancer physician, and this information will help your doctor decide whether to proceed with the follow-up treatment radiotracer that specifically targets and kills the cancer cells indicated on the PET scan. This infusion, which takes place in our Infusion Therapy Suite where we have special treatment rooms and bathrooms designed for theranostics treatments, usually only takes a few minutes, followed by a period of observation. You can then go home. After a few days, the radiation is eliminated through bodily fluids.

Why should I trust UChicago Medicine with my theranostic treatment?

UChicago Medicine physicians and scientists are leaders in both the development and administration of theranostic procedures and are actively conducting research to expand this promising treatment option for other types of cancer. We are the only Illinois hospital to have a medical cyclotron, which is a powerful machine capable of manufacturing new kinds of radiotracers. Our research team partners with experts at Argonne National Laboratory, an internationally renowned facility that has provided instrumental research on using radiation to treat cancer.