Radioligand therapy is an innovative medicine that specifically targets cancer cells. Instead of using chemicals to kill the cancer, it uses radioactivity, a sub-atomic physical phenomenon that can damage cells. Several radioligand therapies, which also may be called radiopharmaceutical therapy or theranostics, are approved for the treatment of a range of cancers, including prostate cancer and neuroendocrine tumors.
“We’ve seen huge success with radioligand therapies, and at Dana-Farber we are actively exploring the use of these therapies in more forms of cancer,” says Praful Ravi, MB, BChir, medical director of Genitourinary Theranostics at the Lank Center for Genitourinary Oncology at Dana-Farber. “I foresee the use of radioligand therapies expanding dramatically in the coming decade.”
How does radioligand therapy work?
Radioligand therapies link together a substance that targets cancer and a radioactive element. The composite drug flows through the body and collects inside the cancer, bringing radioactivity close to cancer cells.
It can be helpful to think of radioactivity as a physical process, as if the radioactive elements were throwing rocks at cancer cells to damage them.
Radioligand therapies consist of radioactive elements that emit different types of radiation. The types of radiation – which take the form of emitted particles – include:
- Alpha particles, which are more energetic, but also heavier, so they don’t travel as far as beta particles.
- Beta particles, which are less energetic but also lighter, so they cover a longer distance.
These particles kill cancer cells while minimizing damage to healthy cells.
Over time – typically over the course of a few days – the radioactivity fades and the drug exits the body as waste.
Dana-Farber is a Comprehensive Radiopharmaceutical Therapy Center of Excellence. The team administers approved therapies and supports clinical trials of radioligand therapies.
“At Dana-Farber, we have highly trained staff to make sure that the radioactivity and these agents are given appropriately to patients and are administered in a safe manner,” says Heather Jacene, MD, clinical director of Nuclear Medicine in the Department of Imaging.
How is radioligand therapy different than chemotherapy?
Radioligand therapy and chemotherapy are both delivered via an IV. They can also have similar side effects, such as low blood counts, fatigue, nausea, and diarrhea. These side effects tend to be much less severe with radioligand therapy than with chemotherapy.
The therapies differ in the way they work. Radioligand therapies are targeted therapies that use radioactivity to kill cancer cells, while chemotherapy is less targeted and uses chemicals to kill cancer cells.
What are the side effects of radioligand therapy?
The side effects of radioligand therapy are like those of chemotherapy, though generally less severe.
With radioligand therapy, there also may be a slight risk of low-level radiation exposure for a few days, and you might be advised to keep your distance from others and manage day-to-day tasks slightly differently. The team preparing you for your treatment will provide detailed guidance for safety.
“We know patients are sometimes concerned about radioactivity, but this therapy is not to be feared,” says Ravi. “Your team will provide instructions for your safety and that of the people close to you.”
What forms of cancer is radioligand therapy used to treat?
Multiple forms of radioligand therapy are currently approved to treat prostate cancer, neuroendocrine tumors, thyroid cancer, and non-Hodgkin lymphoma.
Clinical trials are currently underway testing radioligand therapies and combination therapies involving radioligand therapies in these and other forms of cancer. For instance, Ravi is leading a study of a radioligand therapy in metastatic kidney cancer.
“It is early days, but it is very exciting to be exploring new therapeutic avenues for radioligand therapies,” says Ravi.
Learn more about clinical trials of radioligand therapies at Dana-Farber.
How does my doctor know radioligand therapy is a good choice for me?
Radioligand therapies have a companion diagnostic tool that enables doctors to perform a scan before treatment to see if the medicine is likely to benefit the patient.
This process, called theranostics, involves two steps:
- Imaging to determine if the patient has the marker that the radioligand therapy targets.
- Treatment to deliver the targeted radioligand therapy into the cancer.
For example, several forms of radioligand therapy target PSMA, a marker found on prostate cancer cells. Not all patients have this marker throughout their cancer. If the marker is present, the image will light up the cancer, indicating that the therapy is a good match for the patient.
About the Medical Reviewer
Dr. Praful Ravi is a Medical Oncologist at the Lank Center for Genitourinary Oncology at Dana-Farber Cancer Institute. He received his medical degree from the University of Cambridge and obtained Membership of the Royal College of Physicians (MRCP) before completing a residency in Internal Medicine at Mayo Clinic. He subsequently completed a fellowship in Medical Oncology at Dana-Farber Cancer Institute. He undertakes clinical trials and translational research in prostate cancer, specifically focusing on (1) neoadjuvant therapy in high-risk prostate cancer, (2) radioligand therapy and theranostics, and (3) endpoints and outcomes. He is interested in developing novel treatments and identifying biomarkers that may enable tailoring of cancer therapy to each patient.