RecruitingNAINTERVENTIONAL

Dose Escalated Radiotherapy for Rectal Cancers Using MR-guided Radiotherapy

This study explores a new way to treat rectal cancer with radiotherapy. Standard UK treatment involves 5 weeks of radiotherapy and chemotherapy tablets. This trial increases the radiotherapy dose and uses a special machine called an MR-linac, which combines an MRI scanner with a radiotherapy machine. This allows doctors to precisely target the cancer and adjust treatment daily as the cancer shrinks, aiming to give a stronger dose to the tumour while protecting healthy tissue. The hope is to get rid of the cancer completely, which could mean avoiding surgery and its related problems like needing a stoma. Researchers want to see if this method safely increases the chance of clearing the cancer and reduces side effects compared to standard treatment.

At a glance

Status

Recruiting

Phase

Sponsor

Royal Marsden NHS Foundation Trust

Enrolment target

Start

14 Feb 2025

Estimated completion

13 Jan 2029

Rectal Adenocarcinoma

What is this study about?

This research is looking into a new way to treat rectal cancer with radiotherapy. Normally, in the UK, if you have rectal cancer, you might have radiotherapy for five weeks along with chemotherapy tablets. This delivers a set dose of radiation, 52.5Gy, over 25 daily sessions. This study is testing if giving a slightly higher dose of radiotherapy, 60Gy, could be even better at getting rid of the cancer completely. When the cancer is completely gone after treatment, it's called a 'complete pathological response'. If this happens, some patients might not need surgery and could instead be closely monitored with regular check-ups, scans, and camera tests.

A really important part of this study is using a clever new machine called an 'MR-linac'. Think of it as an MRI scanner and a radiotherapy machine joined together. This MR-linac allows doctors to see the cancer exactly where it is each day and adjust the radiotherapy plan to match. This means they can give a strong, targeted dose to the cancer, even as it changes size during treatment, while trying to protect your healthy body parts like your bowel and bladder. Using this machine also means you won't get extra radiation from daily imaging, unlike with older scanning methods. The aim is to find out if this precise, 'adaptive' way of giving a higher dose of radiotherapy can increase the chance of completely clearing the cancer while keeping side effects low, similar to standard treatment.

The hope is that by precisely targeting the cancer and adapting the treatment as it shrinks, more patients will achieve a 'complete pathological response'. This could potentially allow more people to avoid major surgery, which can sometimes lead to long-term issues like needing a stoma (a surgical opening for waste). While we can't be sure yet, we believe this approach might offer a better chance of getting rid of the cancer and reducing treatment side effects. If this study shows promise, it could lead to bigger trials comparing this new method with standard care to help more rectal cancer patients in the future.

Key takeaways

This study uses a special MRI-guided machine for rectal cancer radiotherapy.
The aim is to increase the chance of completely clearing the cancer.
Avoiding surgery and its long-term side effects (like stoma) is a potential benefit.
Treatment is highly precise, adapting daily to your cancer as it shrinks.
The goal is to keep side effects similar to standard treatment, despite a higher dose.
Participation includes daily radiotherapy, chemotherapy tablets, and follow-up monitoring.

Who may be eligible?

To join this study, you need to be at least 18 years old and have a type of rectal cancer called 'locally advanced rectal adenocarcinoma'. Your doctors would usually recommend combined chemotherapy and radiotherapy for this. You'd also need to be well enough for chemotherapy and able to fit within the treatment area of the special MRI machine.

There are also some reasons why you might not be able to join. For example, if you have something in your body that prevents you from having an MRI scan, like an older type of pacemaker, or if you're very claustrophobic. You also can't have had previous radiotherapy to your pelvis, or certain medical conditions that might make the side effects of this treatment too severe. If you have metal implants in your pelvis that would block the MRI scans, you might also not be able to participate.

Lastly, if you've had certain other cancers recently (within the last 2 years), you might not be eligible. However, some common skin cancers or certain bladder cancers are usually okay, provided they are under control. The study team will review all your medical information carefully to see if this study is suitable and safe 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?
Do you have locally advanced rectal adenocarcinoma?
Are you generally well enough for combined chemotherapy and radiotherapy?
Do you have any metal implants or conditions that prevent you from having an MRI scan?
Have you had radiotherapy to your pelvis before?
Have you had any other serious cancers in the last two years (excluding some skin or bladder cancers)?

Answer every question to see your result.

What does participation involve?

If you decide to take part, you'll have radiotherapy treatment for your rectal cancer. This will involve receiving radiation for five weeks. The main difference is that your treatment will be given on a special MR-linac machine, which combines an MRI scanner with the radiotherapy equipment. This machine allows your medical team to see your cancer in detail every day and adjust your treatment plan to target it as precisely as possible, even if it changes shape or size.

During your treatment, you will also likely take chemotherapy tablets, similar to standard care. You will need to attend regular appointments for your daily radiotherapy sessions. The study also involves filling out some questionnaires about how you are feeling and any side effects you might experience. After your treatment is finished, you will have follow-up appointments, MRI scans, and camera tests (like a flexible sigmoidoscopy) to monitor the cancer and check for any signs of it returning. The exact schedule for these follow-ups will depend on what your local hospital normally does, typically every 3-6 months. The total duration of your active treatment is five weeks, but the follow-up period will be much longer to monitor your health. You can stop participating at any time.

Potential risks and benefits

The main benefit of taking part in this study is the potential for a higher chance of clearing your cancer completely, which could mean you might not need surgery and avoid potential long-term issues like needing a stoma. The precise targeting with the MR-linac aims to give a stronger dose to the cancer while keeping side effects similar to standard treatment by protecting healthy tissue. However, researchers cannot guarantee that the side effects will be less, or that this treatment will definitely lead to a cure. There's a chance of experiencing slightly more bowel or bladder side effects compared to standard treatment, although the MR-linac aims to minimise this. Your doctors will discuss all known potential risks specific to your situation. You are free to withdraw from the study at any time without giving a reason, and this will not affect your future medical care.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

The Royal Marsden Hospital
Verified postcode
Sutton, United Kingdom· Recruiting

Common questions

What is an MR-linac?

It's a special machine that combines an MRI scanner with a radiotherapy machine. This lets doctors see your cancer very clearly each day and adjust your treatment precisely.

Can I avoid surgery if I have this treatment?

The goal is to increase the chance of getting rid of the cancer completely. If this happens, you might be able to avoid surgery and instead have close monitoring.

Will I still have chemotherapy?

Yes, it's expected that you will still take chemotherapy tablets during your radiotherapy, similar to standard treatment.

Will this treatment have more side effects?

The hope is that by being very precise, the MR-linac can keep side effects similar to standard treatment, even with a higher dose. However, there's a chance of slightly more bowel or bladder side effects.

What happens if I change my mind?

You can decide to stop participating in the study at any time, and this will not affect your care.

How to find out more

Brian Hin, FRCR MD(res)

brian.hin@rmh.nhs.uk extension 4228 Official trial record

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