Yes, radium is still used to treat cancer, but in a very different form than most people imagine. The old radium needles and plaques that defined early 20th-century cancer treatment were phased out after World War II, replaced by cheaper, safer man-made radioactive materials. What persists today is a modern pharmaceutical called radium-223, a specific isotope engineered into an injectable drug for advanced prostate cancer that has spread to the bones.
How Modern Radium-223 Differs From Historical Radium
The radium used in early cancer treatment was radium-226, a naturally occurring element isolated from uranium ore. Hospitals packed it into needles or plaques and placed them directly against tumors, particularly cervical and skin cancers. It worked, but it was expensive, dangerous to handle, and exposed healthy tissue to significant radiation. As Memorial Sloan Kettering Cancer Center notes, once nuclear reactors made it possible to produce artificial radioactive elements after World War II, radium-226 was steadily replaced by alternatives like cobalt-60 and cesium-137 that were easier to produce and control.
Radium-223 is an entirely different approach. Rather than being placed against a tumor from the outside, it’s injected into a vein and travels through the bloodstream to find bone metastases on its own. It was approved by the FDA in 2013 under the brand name Xofigo, specifically for patients with castration-resistant prostate cancer who have symptomatic bone metastases and no known cancer spread to internal organs.
Why Radium-223 Targets Bone So Precisely
Radium sits in the same column of the periodic table as calcium, which means the body treats it like calcium. When injected, radium-223 travels to areas of active bone formation and substitutes for calcium in hydroxyapatite, the mineral compound that makes up bone tissue. Prostate cancer bone metastases trigger rapid, abnormal bone growth around them, creating exactly the kind of active bone-building environment that attracts radium-223. The drug preferentially incorporates into newly formed bone matrix within these metastatic lesions.
Once embedded in the bone around a tumor, radium-223 emits high-energy alpha particles. These are heavy, powerful particles, but they travel less than 100 micrometers (roughly the width of a single human hair). That extremely short range is the key advantage: the radiation is intense enough to cause lethal DNA damage in nearby cancer cells, breaking both strands of their DNA, while largely sparing healthy tissue just a fraction of a millimeter away. This precision also limits damage to the bone marrow, which is the blood cell factory inside bones and a frequent casualty of less targeted radiation treatments.
What Treatment Looks Like
Radium-223 is given as a series of six intravenous injections, spaced four weeks apart. Each dose is calculated based on body weight. The full course takes about six months to complete, though the schedule allows some flexibility: each injection can be given within a window of three days early to seven days late, with delays of up to four weeks permitted if side effects need time to resolve.
Before starting treatment, you’ll need imaging to confirm that cancer has spread to the bones and to rule out spread to internal organs like the liver or lungs. This typically involves a bone scan or PSMA PET scan to confirm bone metastases, plus a CT scan of the chest, abdomen, and pelvis to check for visceral disease. Radium-223 is only approved for patients whose cancer is in the bones, not in soft tissue organs.
After each injection, radiation safety precautions at home are minimal compared to some other radioactive treatments. Alpha particles don’t penetrate through the skin, so you don’t need to keep physical distance from family members. The main precaution for the first seven days is wearing double gloves when handling urine or feces, since the drug is partly excreted through the digestive tract. Any urine or blood drops can be cleaned with flushable wipes.
Side Effects to Expect
The most common side effects reported in clinical trials were nausea, bone pain, and anemia. Because radium-223 concentrates in bone, it can affect blood cell production despite its short radiation range. Post-approval safety monitoring has confirmed that blood-related side effects are the most significant concern. Anemia (low red blood cells), thrombocytopenia (low platelets), and in more serious cases, broader bone marrow suppression have all been flagged. Low platelet counts appear at roughly three times the rate seen with other cancer treatments, based on global adverse event reporting data.
Bone pain can temporarily worsen before improving, which is a known pattern with bone-targeted therapies. Your medical team will monitor blood counts regularly throughout the six-month treatment course, and doses may be delayed if counts drop too low.
How Well It Works
The landmark clinical trial for radium-223, called ALSYMPCA, was published in the New England Journal of Medicine and demonstrated a meaningful survival benefit. Patients receiving radium-223 lived significantly longer than those receiving a placebo, which led to the drug’s FDA approval. The trial enrolled men with castration-resistant prostate cancer and bone metastases who had either already received chemotherapy or were not candidates for it.
Beyond survival, radium-223 delayed the time before bone-related complications occurred, things like fractures, spinal cord compression, or the need for radiation to manage bone pain. For patients dealing with painful bone metastases, this delay in skeletal complications is a practical quality-of-life benefit.
Where Radium-223 Fits Among Other Treatments
Radium-223 occupies a specific niche. It is not a first-line prostate cancer treatment. It’s reserved for men whose prostate cancer continues growing despite hormone-suppressing therapy (castration-resistant disease), has spread to the bones with symptoms like pain, and has not spread to internal organs. Several other drug classes are also approved for this stage of disease, including hormone pathway inhibitors, chemotherapy, PARP inhibitors, and immunotherapy. Doctors often sequence these treatments based on a patient’s overall health, prior treatments, and specific disease characteristics.
Researchers are actively studying whether combining radium-223 with other drugs could improve outcomes. The way radium-223 damages tumor DNA creates a theoretical rationale for pairing it with PARP inhibitors, which block cancer cells from repairing DNA, or with immunotherapy agents that may respond to the cellular damage radium causes. Combinations with bone-strengthening agents are also being explored to reduce the fracture risk associated with treatment.
So while the era of radium needles and “radium hospitals” is long gone, radium itself has been reinvented. In its modern form, it’s a precisely targeted treatment for a specific and difficult stage of prostate cancer, one that exploits the body’s own bone chemistry to deliver radiation exactly where it’s needed.