RecruitingPHASE2INTERVENTIONAL

Phase II Randomized Trial of 2 Versus 5 Fraction Prostate Stereotactic Ablative Radiotherapy for Intermediate Risk Prostate Cancer

This study, called ADAPT-2, is looking at men with a common type of prostate cancer that hasn't spread. It compares two ways of giving a special type of radiation therapy called SABR. One way is the standard 5 treatment sessions, and the other is a new approach with only 2 sessions. The main goal is to see if having fewer sessions reduces side effects, improves quality of life, and is just as effective at controlling the cancer. Both methods use special techniques to protect nearby organs. We also explore how a new computer program (AI) might help guide treatment in the future. The study aims to find the best and most convenient treatment for patients.

At a glance

Status

Recruiting

Phase

PHASE2

Sponsor

British Columbia Cancer Agency

Enrolment target

100

Start

04 Sep 2025

Estimated completion

30 Apr 2033

Prostate CA

What is this study about?

Prostate cancer is quite common among men, and thankfully, if it hasn't spread, there are often several ways to treat it effectively. One modern treatment option is called Stereotactic Ablative Radiotherapy, or SABR for short. This is a very precise type of radiation therapy where a small number of strong radiation doses (usually 5 to 7 sessions) are given directly to the prostate. Many studies have shown that 5-session SABR works very well, often as good as other treatments, and can lead to fewer side effects and a better quality of life compared to surgery.

Now, imagine if we could get the same excellent results, but with even fewer treatment sessions. That's what this study is exploring! It's comparing the standard 5-session SABR with a new approach that uses only 2 sessions. The hope is that fewer sessions could mean even better cancer control, fewer side effects, and be much more convenient for patients. While some smaller studies suggest 2-session SABR might be effective and well-tolerated, we don't yet have enough information comparing it directly to 5-session SABR to know which is truly better.

To make sure this treatment is as safe as possible, both the 2-session and 5-session approaches in this study will use special techniques. This includes continuously tracking the prostate gland during treatment to ensure the radiation hits the right spot, and using a special gel (called SpaceOAR Hydrogel) placed between the prostate and the bowel to protect nearby organs and reduce side effects. The study will also be looking at a new computer program that uses artificial intelligence (AI) to see if it could help guide radiation treatment even more accurately in the future. This AI part is like a trial run; the AI won't directly guide your treatment during the study, but researchers will see if it could be useful later on.

Key takeaways

Compares 2 versus 5 radiation sessions for prostate cancer.
Aims to find out which approach has fewer side effects and a better quality of life.
Uses advanced techniques to protect nearby organs during treatment.
Helps researchers understand the best way to treat intermediate-risk prostate cancer.
Investigating if AI can improve future radiation planning.
Participation involves close monitoring for long-term health.

Who may be eligible?

This study is for men aged 18 or older who have been diagnosed with certain types of prostate cancer that doctors consider to be 'intermediate risk' and that hasn't spread to other parts of the body. You would need to be generally healthy enough to undergo the treatments and follow-up appointments, with an expected lifespan of more than 5 years.

You cannot join this study if your cancer is considered more advanced, for example, if it has spread to lymph nodes or other organs, or if it's a very aggressive type (Gleason score 8 or higher, or PSA over 20). Your prostate size also needs to be below a certain limit. You'll need to be willing to have small markers placed in your prostate and a special gel placed to protect your bowel during treatment.

If you're already receiving hormone therapy (Androgen Deprivation Therapy, or ADT), you might still be able to join, depending on when your treatment started and if it's possible to complete the radiation part of the study before you finish 6 months of ADT. Your doctor will carefully review all your medical information to see if this study is a good fit for you.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you 18 years old or older?
Have you been diagnosed with 'intermediate risk' prostate cancer that hasn't spread?
Are you generally healthy enough for treatment and follow-up for several years?
Are you willing to have small markers and a special gel placed before radiation?
Do you have a life expectancy of more than 5 years?

Answer every question to see your result.

What does participation involve?

If you decide to join this study, you will be randomly assigned to receive either 2 or 5 sessions of prostate SABR. Before your treatment begins, you will have small markers placed in your prostate (called fiducial markers) and a special gel (SpaceOAR Hydrogel) injected between your prostate and bowel – these help ensure accurate treatment and protect nearby organs. You will then receive your assigned radiation treatment in either 2 or 5 sessions over a period of 1 to 2 weeks. Throughout the study, you'll have regular check-ups, which may include blood tests (like PSA), scans, and questionnaires to monitor your recovery, side effects, and overall quality of life. The total duration of follow-up for this study will be several years, as researchers want to understand the long-term effects of the treatments.

Potential risks and benefits

Participating in this study could offer you the potential benefit of a treatment that might have fewer side effects, improve your quality of life, and be more convenient with fewer hospital visits. You would also be contributing valuable information that could help improve prostate cancer care for future patients. However, like all medical treatments, there are potential risks, including side effects from the radiation (such as changes in bowel or bladder habits, or sexual function), and risks associated with placing the fiducial markers and rectal gel. The study aims to minimize these risks by using proven techniques to protect surrounding organs. You have the right to withdraw from the study at any time, for any reason, without it affecting your usual medical care.

Locations (1)

BC Cancer Radiation Oncology
Verified postcode
Victoria, Canada· Recruiting

Common questions

What is SABR?

SABR (Stereotactic Ablative Radiotherapy) is a very precise type of radiation treatment for cancer that uses strong, focused beams to target the tumour with fewer, higher doses.

What does 'intermediate risk' prostate cancer mean?

It means your prostate cancer has certain features that put it at a moderate chance of growing or spreading, but it's not yet considered high-risk or spread outside the prostate.

Will I get to choose between 2 or 5 sessions?

No, you will be randomly assigned to receive either 2 or 5 sessions, like flipping a coin. This helps make the study fair and scientific.

What is the 'rectal spacer'?

It's a special gel (SpaceOAR Hydrogel) placed between your prostate and your bowel to create a small gap, protecting your bowel from radiation and reducing side effects.

What is the role of AI in this study?

Researchers are testing a new AI computer program to see if it could help target radiation more accurately in the future, but it won't be used to guide your actual treatment in this study.

How to find out more

Cathy Tran

cathy.tran@bccancer.bc.ca 250 519 5500 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.