A new theranostics suite at UCHealth University of Colorado Hospital, overseen by University of Colorado Anschutz Cancer Center members, is streamlining treatment and clinical trials for certain types of cancer, notably prostate cancer and neuroendocrine tumors (NETs), particularly of the gastrointestinal tract and pancreas. It is also used to treat certain thyroid cancers.
A combination of therapy and diagnostics, theranostics combines diagnostic imaging and targeted radioactive treatment of cancer cells using a molecular targeting imaging agent to identify areas of cancer in the body, then deliver radiation directly to those cells, sparing patients from the side effects of chemotherapy.
“Theranostics offers a precision medicine approach by directly combining diagnostics with targeted therapy,” says Chris Lieu, MD, associate director of clinical research at the CU Anschutz Cancer Center. “Standard systemic treatments, like chemotherapy, circulate throughout the entire body. Theranostics uses a radioactive diagnostic tracer to locate targets present on the tumor. This allows us to deliver a matching therapeutic radioactive isotope that binds specifically to those cells. The hope is that this allows us to deliver high doses of radiation directly to the tumor while minimizing damage to surrounding healthy tissue.”
Treatment on target
In the theranostics suite in the Anschutz Outpatient Pavilion, patients who are referred by their oncologists receive a low-energy radiopharmaceutical agent that attaches to the surface of cancer cells, allowing radiologists to use special 3D imaging equipment, such as SPECT/CT, PET/CT, or PET/MRI, to locate specific areas of cancer in the body. A higher-energy radioactive medicine is then administered by infusion, attaching to the same cells and slowly killing them over a period of days.
“This therapy is much less disabling than systemic chemotherapy,” says cancer center member Bennett Chin, MD, professor of radiology-nuclear medicine, who oversees the theranostics suite. “Patients' side effects are much lower, and it's much better tolerated. With external beam radiation, they can only focus the beam on a certain part of the body where the tumor is large already. With theranostics, we can treat the disease that we see, but even smaller amounts of disease that are difficult to see. Our therapies home even to small tumors and treat cancer throughout the body.”
The prostate theranostics treatment is typically delivered in a course of six infusions over six weeks, each infusion only lasting about a minute, Chin says. Imaging can be repeated to see the effects of the treatment; in prostate cancer, prostate-specific antigen (PSA) levels also are checked before and after the treatment course.
“About 50% of prostate cancer patients treated with this therapy have a decrease of at least 50% of their serum PSA,” he says.
Empowering clinical trials
The new theranostics suite also improves operational capacity for running radiopharmaceutical clinical trials — clinical trials looking at using theranostics technology to treat other kinds of cancer.
“Clinical trials are the backbone of advancing these therapies,” Lieu says. “As a Society of Nuclear Medicine and Molecular Imaging-designated Comprehensive Radiopharmaceutical Therapy Center of Excellencesince 2022, we run complex, early-phase trials that require highly specialized infrastructure. We are now exploring the application of theranostics in other GI malignancies, including pancreas and colorectal cancer, where targeted treatments are desperately needed.”
The opening of the theranostics suite coincides with the renewal of the University of Colorado’s Society of Nuclear Medicine and Molecular Imaging (SNMMI)-designated Comprehensive Center of Excellence. The prestigious designation recognizes the University of Colorado as a national leader in delivering advanced radiopharmaceutical therapies supported by experienced multidisciplinary teams, sophisticated imaging capabilities, and ongoing research. The designation identifies centers meeting SNMMI's comprehensive standards for expertise, infrastructure, patient care, and advancement in the field of medical oncology, novel targeted radiation therapy and advanced imaging.
In the GI space, Lieu says, cancer center researchers are looking at extending peptide receptor radionuclide therapy (PRRT) to higher-grade gastroenteropancreatic neuroendocrine tumors (GEP-NETs) through trials that compare these radioligands against current therapies.
“We are also seeing the emergence of exciting early-phase trials evaluating next-generation therapies for advanced solid tumors,” he says. “A major ongoing focus for our research teams will be identifying novel targets on pancreatic and colorectal tumors so we can bring the success we’ve seen in NETs and prostate cancer into these challenging GI cancers.”
Featured image: Bennett Chin, MD, and others celebrate the new theranostics suite at a ribbon cutting ceremony in August.
