Radium-223 Treatment for Metastatic Prostate Cancer - Ila Sethi

August 17, 2021

As part of this patient-centered video series of lectures on prostate cancer diagnosis and treatment, Dr Sethi presents the timing for radium-223 treatment in mCRPC.  She details who qualifies as a candidate for radium 223 therapy, how it is given, the limited side effects of this treatment, that PSA is not a biomarker for treatment success and other treatment management considerations.

Biography:

Ila Sethi, MD, Assistant Professor, Department of Radiology and Imaging Sciences Emory University School of Medicine


Read the Full Video Transcript

Ila Sethi: Hello and welcome. My name is Ila Sethi and I am a Nuclear Medicine Physician at Emory University. Thank you for joining me for this presentation today. This presentation is part of a patient-centered video series of lectures on prostate cancer diagnosis, and treatment, which is organized by the society of nuclear medicine and molecular imaging.

The focus of my talk today is Radium 223, which is a radionuclide therapy approved for advanced-stage prostate cancer with metastatic bone disease. And I'm going to talk about various aspects of this treatment. So what does it mean to have metastatic bone disease as a result of prostate cancer? It essentially means that cancer has spread to the bones now, and the incidence of bone metastasis is significant. It is seen in up to 85% of patients with prostate cancer. And the way it presents is either with pain or fractures that can happen with minimal trauma.

Sometimes there can be an increase in blood calcium levels. If the bones involved are actually the vertebral column, there can be compression of the spinal cord and the symptoms would depend upon what part of the spinal cord is getting compressed.

What are the treatment options available? So the treatment options that are available, include analgesics for pain control, chemotherapy, hormone therapy, radiation therapy, steroids, surgery, and radionuclide therapy, including Radium 223.

Let's talk about who is a candidate for Radium 223 therapy. A patient who has painful metastatic disease, and the pain is now inadequately controlled by pain medications or the patient has become intolerant to pain medications. The disease has become resistant to hormone therapy, and there is no evidence of visceral disease.

How does this work? So Radium 223 is essentially an analog of calcium, which means that it accumulates in the bone at the site of increased bone activity. Wherever there is a metastatic disease in the bone, that area would have increased bone activity. And once it gets deposited to that area of metastasis, it emits alpha radiation, which is a kind of particulate radiation, and then it would kill tumor cells locally.

So you may want to ask what preparation does one needs for this therapy? So there are a few things to consider. Fasting is not needed. And then if you are prone to nausea, you may ask for an anti-nausea script from your oncologist. And then other medications like for diabetes, hyperlipidemia, high blood pressure, you can take those medications as usual.

However, it is recommended that if you are taking supplements, including calcium and vitamin D, it is recommended that you may want to pause those four days before and 4 days after the therapy. If incontinence is an issue, your oncologist may want to consider a catheterization, or one may want to use absorbent pads as needed.

So how is the treatment given? This can be done as an outpatient. You do not need to stay in the hospital. This is a set of six IV injections given slowly over a period of one minute, and these are given at four-week intervals. So once the injection is given, that is when the radiation safety precautions kick in and you have to observe the radiation safety precautions for seven days after each treatment. And your oncologist, and your nuclear medicine team, will talk in great detail about these radiation safety precautions, but a few key aspects of these precautions, I just want to emphasize.

So the basic principle that you need to understand is once the drug, once the treatment goes in, you become the source of radiation. The goal of these precautions, there are two goals; one is to protect others from any radiation, and the second is, to protect your own body from any harmful effects of the radiation. So once it goes inside the body, it is excreted in all bodily fluids, including urine, sweat, saliva, all bodily secretions. So the goal is to not have any person come in contact with those secretions.

The way to do this is to have a separate bathroom for yourself. Drink plenty of water, use the bathroom frequently, flush twice after every use, et cetera. Then there is a specific recommendation related to sexual activity while getting this treatment. It is recommended that condoms be used for intercourse and the female partners should also use contraception because this drug can cause fetal harm.

What are the other side effects? So the most commonly seen side effects are diarrhea, nausea, vomiting, a decrease in platelets, which are the clot-forming cells, and what that can do is lead to increased bleeding tendencies or an increase in bruising. These side effects are seen in approximately 10% of the patients. Other uncommon side effects include a decrease in white blood counts, which may lead to increased susceptibility to infections.

So there are a few more considerations related to Radium 223. One is, what if there is a delay in the subsequent treatment? As I mentioned, these treatments are four weeks apart. So the scientific literature shows that if there is a delay for up to four weeks, that does not alter the efficacy of the treatment. However, if the delay is beyond four weeks, this hasn't been studied and that can totally be at the discretion of your oncologist to proceed with the treatment.

Then the other question that comes to mind is how long does this treatment work? So the literature that we have, according to that literature, it gives a survival benefit of 14.9 months and a 30% decrease in the risk of death, so something to consider. Another consideration is, can you have it more than once? So the answer to that, we do not know yet because there is no scientific literature widely researched and accepted that talks about the efficacy and safety of a second six injection regimen. So again, this can totally be at your own oncologist's discretion.

So the take-home message, one thing that I want you to remember from this talk, this is a valid alternative that has the potential to improve quality of life. Talk to your oncologist and see if you are a candidate for this therapy. If you have any questions, this is my email address, . Feel free to write to me with any questions.

And last but not least, I want to acknowledge our prostate cancer outreach working group who have been working very hard to put these CDs together. Once again, thank you for joining me. Thank you for your time.
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