Theranostics, offered within the Froedtert & the Medical College of Wisconsin Cancer Network, combines a diagnostic test with delivering treatment at the same time. It is a type of precision, or personalized, medicine in which the right treatment is chosen based on specific disease characteristics and each person’s unique biological profile.
The key to theranostics is targeting a specific protein or receptor on the surface of a cancer cell. Physicians choose a ligand — a molecule that binds to cancer cells. The ligand is attached to a radioactive tracer for an imaging scan. It binds to targeted cancer cells, which appear as bright spots in the scan. Next, the ligand is paired with radioactive material and injected into the bloodstream. It zeros in on cancer cells, binds to them and delivers treatment.
“With theranostics, we locate cancer cells in the body and stage them with a positron emission tomography (PET) scan, which uses low-energy radiation,” said Michael Holt, MD, diagnostic radiologist and MCW faculty member. “That’s the diagnostic part. In the treatment aspect, alpha- or beta-emitting radiopharmaceutical particles attach to the ligand and bind to tumor cells. The radioactive particles treat the cancer.”
Highly Focused Radiation Directly Targets Tumors
William Hall, MD, radiation oncologist and MCW faculty member, describes it as radiation therapy — in a different form.
“Like radiation therapy delivered externally, theranostics precisely targets tumors with highly focused radiation,” he said. “Think of it as liquid radiation.”
He compared theranostics’ mechanism to “like attracting like.” “For example, if the protein target on a cancer cell looks like a triangle, the ligand will find triangles only,” Dr. Hall said. “It targets tumor cells’ DNA to eliminate the cancer.”
With such precise targeting, effects on surrounding healthy tissues are minimal.
Theranostics Could Evolve Through Clinical Trials
While theranostics is available for patients with limited types of cancer, it is expected to evolve quickly through clinical trials. It does not cure cancer, but it can slow its growth and improve quality of life, especially when cancer is advanced or hard to treat with standard therapies.
To date, the Froedtert & MCW theranostics team has treated almost 200 people with prostate cancer and nearly 100 patients who have neuroendocrine tumors, a rare cancer.
“Theranostics offers huge potential,” Dr. Hall said. “In the future, we anticipate making it available to treat people who are experiencing other types of cancer.”
Learn more at froedtert.com/theranostics. For an appointment, call the Froedtert & MCW Cancer Network at 414-805-0505.
