A New Approach for Intermediate-Risk Prostate Cancer: The IRRADIANT Trial

By: David Grew MD MPH

“The IRRADIANT Trial is studying how to control prostate cancer while reducing long-term side effects."

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When patients are diagnosed with intermediate-risk prostate cancer, one of the first questions is often: What treatment will control the cancer while causing the fewest long-term side effects?

The IRRADIANT Trial is a new study designed to help answer that question.

This trial is for some patients with intermediate-risk prostate cancer. It compares two different ways of delivering a targeted “boost” to the area of the prostate that appears to contain the most aggressive cancer.

The goal is to learn whether a newer approach may offer similar cancer control while reducing long-term effects on urinary, bowel, and sexual function.

Standard treatment for intermediate-risk prostate cancer

Today, the standard treatment options for intermediate-risk prostate cancer often include surgery or radiation therapy.

With surgery, the prostate is removed. With radiation therapy, the prostate receives a high dose of radiation over a series of treatments.

These treatments can be very effective. But they can also lead to side effects that affect quality of life. Some patients experience changes in urination, bowel habits, or sexual function after treatment. And in some cases, the cancer may return even after treatment.

That is why researchers continue to study whether treatment can be made more precise.

What is a “boost” in prostate radiation?

For some patients receiving stereotactic body radiation therapy, also called SBRT, doctors may give an extra dose of treatment called a boost.

A boost is designed to target the part of the prostate where the cancer appears to be most aggressive.

One way to do this is with a radiation boost, in which the higher-risk area receives a higher dose of radiation while the rest of the prostate receives a lower standard dose.

Another possible way is with a newer technique called irreversible electroporation, or IRE.

What is IRE?

IRE is a treatment that uses short bursts of electrical energy to target and destroy tissue in a specific area.

In this study, doctors use a device called the NanoKnife System, which delivers IRE. The NanoKnife System has been cleared by the FDA for prostate tissue ablation, meaning it can be used to destroy prostate tissue in the area where cancer is located.

Researchers want to know whether using IRE as the boost approach, followed by lower-dose radiation to the rest of the prostate, could provide outcomes similar to a standard radiation boost while potentially causing fewer long-term side effects.

What is the IRRADIANT Trial studying?

The main question in the IRRADIANT Trial is this:

Can an IRE boost plus lower-dose radiation control prostate cancer as well as a standard radiation boost approach, while improving long-term quality of life?

To help answer that, patients in the study are randomly assigned to one of two treatment groups.

Group 1: Standard radiation boost

Patients in this group receive all of their treatment with radiation.

The area of the prostate with the most aggressive cancer gets a higher dose, while the rest of the prostate receives a standard lower dose. This is a treatment approach already used in some centers.

Group 2: IRE boost plus lower-dose radiation

Patients in this group first receive an IRE boost to the most aggressive tumor area.

Doctors apply carefully controlled electrical pulses to the targeted area in an effort to destroy cancer cells while sparing nearby healthy tissue as much as possible.

Then, about 6 to 12 weeks later, patients receive lower-dose radiation to the rest of the prostate.

Researchers hope this combination may help preserve quality of life while still keeping the cancer under control.

How do doctors decide where to target treatment?

The IRRADIANT Trial uses advanced imaging to understand better where the cancer is and how aggressive it appears to be.

Doctors may use scans such as:

• MRI
• PSMA PET

These imaging tools help map the prostate and identify the area most likely to need the boost treatment.

That information is then used to guide treatment planning as precisely as possible.

What will doctors measure in this study?

Doctors will follow patients for two years after treatment.

They want to learn:

• how often the cancer returns
• whether side effects differ between the two groups
• how treatment affects urinary, bowel, and sexual health

Patients in the trial will also be asked to complete surveys at different time points after treatment so researchers can better understand how each approach affects daily life.

This is important because cancer control is only part of the picture. For many patients, quality of life after treatment matters deeply too.

Why might a patient consider joining this study?

A patient who enrolls in the IRRADIANT Trial may have the chance to receive effective treatment while also helping doctors learn which boost strategy may be better for future patients.

By comparing standard radiation boost with IRE boost plus lower-dose radiation, the study may help clarify whether one approach offers a better balance between controlling the cancer and reducing long-term side effects.

Who may be eligible?

This study may be an option for some patients with intermediate-risk prostate cancer.

The best way to find out whether a patient may qualify is to speak with a doctor or study team member, since every clinical trial has specific eligibility criteria.

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The IRRADIANT Trial is exploring an important question in prostate cancer care: how to treat the cancer effectively while protecting long-term quality of life as much as possible. For patients with intermediate-risk prostate cancer, that balance can make a big difference.

To learn more about the IRRADIANT clinical trial, watch the video we made here.

To learn more, browse our library of prostate cancer-related topics.

Hire PRIMR to create custom video content for your clinical trial or medical product today.

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FAQs:

How long does treatment in the IRRADIANT Trial take from start to finish?

The exact timeline may vary depending on which treatment group a patient is assigned to and how scheduling works at the study site. Patients can ask the study team how long the imaging, procedures, radiation treatments, and follow-up visits are expected to take.

Will I need anesthesia or sedation if I receive the IRE treatment?

Some patients may wonder what the IRE procedure feels like and whether they will be asleep during it. The answer may depend on how the procedure is performed at the study center, so this is an important question to ask the treating team before enrolling.

Can I still join the study if I have other health conditions or take regular medications?

Possibly, but it depends on the study’s eligibility rules. Certain medical conditions, prior procedures, or medications may affect whether a patient can safely participate, so the study team will review a patient’s medical history carefully.

What happens if my cancer comes back after treatment on this trial?

Patients may want to know what options would still be available in the future if the cancer returns. This can vary from person to person, but asking about possible next steps after trial treatment is a reasonable and important part of the decision-making process.

Will participating in this trial require extra visits, tests, or travel compared with standard treatment?

In many clinical trials, patients may need additional imaging, surveys, follow-up visits, or monitoring. Patients considering the IRRADIANT Trial should ask what extra time commitments may be involved and whether any travel or scheduling support is available.

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