A Roadmap to Radioligand Therapy for Breast Cancer
Radioligand therapy—also known as radiopharmaceutical therapy, also known as really promising stuff—has been making waves in prostate cancer for a few years now. In fact, since 2022, patients with metastatic prostate cancer have had access to this targeted, radioactive, tumor-zapping therapy that sounds like it belongs in a Marvel movie. But when it comes to breast cancer? Not so fast. The breakthroughs have been slower, the headlines fewer, and the clinical trials just now picking up steam.
Why the delay? That’s the billion-dollar (and life-saving) question.
So, What Is Radioligand Therapy?
Radioligand therapy (RLT) is a cutting-edge precision medicine that combines radioactive isotopes with molecules designed to seek out and bind to cancer cells. Once attached, these molecules deliver a targeted, microscopic nuclear dose to destroy cancer cells while sparing healthy tissue, unlike the widespread impact of traditional chemotherapy. Before treatment, PET scans confirm the presence of the therapeutic target, enabling a tailored approach. This powerful integration of diagnostic imaging and targeted radiopharmaceutical delivery, known as theranostics, offers a highly personalized strategy for cancer treatment.
The prostate cancer world embraced this approach early and has seen meaningful clinical benefits. Breast cancer, on the other hand, has been waiting in the wings. But now, finally, it's starting to get its moment in the radiopharmaceutical spotlight.
Why Is Breast Cancer Late to the Theranostic Party?
There’s no one-liner answer here, but let’s consider a few theories:
Biology is messy: Prostate cancer has a more consistent molecular target—PSMA (prostate-specific membrane antigen)—which made it easier to design radioligand therapies. Breast cancer? It's more like a messy family reunion, with multiple subtypes, varying targets, and inconsistent expression of any one molecule across patients.
Money talks... and sometimes whispers when it comes to women’s health: Let’s not sugarcoat it—there may be bias in how resources are allocated for drug development. Despite breast cancer being one of the most common cancers in the world, investments in novel therapies like RLT have lagged. I’ve been asking pharma reps for years, “Why didn’t you start on this 5 or 10 years ago?” The silence is deafening.
Complexity of targeting: Many potential targets for breast cancer RLT are still under investigation. While some agents show promise, none are FDA-approved yet. Most are in early-phase clinical trials, meaning the road to market approval is still long and winding.
The Promise of Radioligand Therapy in Breast Cancer
Here’s where things get exciting. Based on early data and logical extension from what we’ve seen in prostate cancer, I believe that RLT has the potential to revolutionize breast cancer care. Once available, it could be used not only in patients with stage IV metastatic disease, but possibly even in earlier stages—especially for treatment-resistant or high-risk subtypes.
Picture this: A woman with metastatic breast cancer undergoes a specialized PET scan to see which RLT target lights up in her body. Based on that scan, she receives a tailored radioligand therapy—maybe more than one over time, depending on how her cancer evolves and what her bone marrow can handle.
We’re not talking about a replacement for current treatments. We’re talking about a powerful addition—a new arrow in the oncologic quiver.
What Makes Breast Cancer RLT More Complicated?
Unlike prostate cancer, where one target (PSMA) does most of the heavy lifting, breast cancer RLT may need a menu of options. Many of the targets under investigation are only present in about a third of patients with metastatic disease. That means we’ll likely need to screen each patient with multiple PET scans using different agents to determine which therapy is most likely to work.
This brings up a few logistical challenges:
Multi-agent PET imaging: Patients may need more than one scan with different tracers to find their optimal match.
Limited radiologist and nuclear medicine bandwidth: Reading multiple full-body PET scans for every patient? That’s a hard no. We may need to move toward limited field-of-view imaging and more streamlined protocols.
Single-timepoint multi-agent PET: This promising approach involves injecting multiple tracers at once and scanning at a single timepoint to save time, cost, and staff resources. While nearing clinical adoption for cardiac imaging, such an approach is not currently available for cancer imaging.
This is doable. But this requires planning, coordination, and innovation—not just on the science side, but operationally and financially.
Will RLT Play Nice With Other Treatments?
Almost certainly. One of the most exciting aspects of RLT is how well it could integrate with existing therapies. Whether it's endocrine therapy, chemotherapy, targeted antibodies, immune checkpoint inhibitors, or even external radiation, radioligand therapy is likely to be additive—not competitive.
In other words, it won’t be “either/or.” It’ll be “yes, and.”
What Needs to Happen Next?
To make this all a reality, a few dominoes need to fall:
Speed up clinical trials – These are costly and time-intensive but critical for advancing radioligand therapy. While some trials may fall short, others could yield transformative results. Substantial investment from pharmaceutical companies, research institutions, and other stakeholders is urgently needed to fast-track development and bring this promising therapy to patients sooner.
Expand infrastructure – More clinics, more trained personnel, and more logistical support for delivering radiopharmaceuticals.
Ensure reimbursement – Payers need to be prepared for what could become a high-demand, high-cost, high-impact therapy.
Continue advocacy – Women with breast cancer deserve the same investment and innovation that other patient groups have received.
The Bottom Line
Radioligand therapy for breast cancer isn’t science fiction—it’s science that’s finally starting to catch up with the need. The potential is enormous. The stakes are high. And the urgency is real.
A new class of treatment is knocking on the door. The question is: How long will it take us to answer?
If we do this right, we’ll not only give patients more time—but more quality time. And that, after all, is the point.
Enjoyed this article? Explore more of my insights on AI in breast imaging and common media misconceptions about AI in radiology through the links below.
A Letter to the Media: Can we Please Get Real About AI in Radiology?
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