A study looking at increasing the dose of radiotherapy to areas of cancer inside the prostate gland (DELINEATE)

You may be able to enter this study if you

• Have been diagnosed with localised prostate cancer, are being treated at the Royal Marsden Hospital and your doctors think there is a medium or high risk of your cancer growing or spreading
• Are well enough to carry out all your normal activities, apart from heavy physical work (performance status of 0 or 1)
• Are at least 18 years old

You cannot enter this study if you

• Have cancer that has spread to the semial vesicles, lymph glands in your pelvis or other body organs
• Have a PSA level of 50 or over
• Have already had radiotherapy to your prostate gland or to the area between your hip bones (your pelvis)
• Have had surgery to remove your prostate gland (a radical prostatectomy)
• Have had hormone therapy previously, or have recently started it
• Have had any other type of cancer in the last 5 years, apart from non melanoma skin cancer
• Can’t have MRI scans, for example because you have some metal in your body, or have a pacemaker
• Have had both your hips replaced
• Have any other medical condition (or have had any other treatment) that the doctors think could make the side effects of radiotherapy worse
• Take medication to thin your blood (anticoagulants) and you would not be able to stop taking this for about a week
• Had an infection or a lot of bleeding after having a biopsy of your prostate

The study will recruit 100 men who are having treatment at the Royal Marsden Hospital, with the aim of finding 50 patients who have an area of cancer (a cancer nodule) seen on an MRI scan that can be targeted with a higher dose of radiotherapy.

If you agree to join the trial, you start by having an MRI scan. During this scan, you have a small magnetic coil put inside your back passage. This makes the scan more accurate.

You then start hormone therapy to lower the testosterone level in your body. This can help to shrink your prostate gland and the cancer. You have tablets for 1 to 2 weeks and then an injection. The study team will give you more information about this, but having hormone therapy alongside radiotherapy is a standard treatment for prostate cancer.

A radiologist will study the images from your MRI scan. If they can clearly see an area of cancer (a nodule) inside your prostate gland that they can target with a higher dose of radiotherapy, you can continue in the study. If they cannot see a nodule clearly, you will have standard radiotherapy.

If you continue in the study, the researchers need to put some small gold seeds into your prostate gland – they are about the size of a grain of rice.  They put the seeds in during a transrectal ultrasound. This is similar to the prostate biopsy that you would have had to diagnose your cancer. To lower the risk of infection, you take antibiotics for a few days before and after the seeds are put in. And if you take drugs to thin your blood (anticoagulants), the study team will ask you to stop taking them 5 to 7 days beforehand.

At least 5 days after having the gold seeds put in, you have another MRI or CT scan to plan your radiotherapy. You do not have the coil put in this time. You may have a thin tube called a catheter put into your bladder through your penis. This is to make sure that the area of the prostate gland getting the higher dose of radiotherapy doesn’t include the tube that carries urine out of the body (the urethra).

You start radiotherapy about 3 weeks after your planning session. Each time you have treatment, the study team take images to check the position of your pelvis and the location of the gold seeds in your prostate gland. Checking this will make each radiotherapy session about 5 minutes longer.

Some men will join a sub study looking at using a special type of biopsy called a transperineal template mapping biopsy. If you agree to take part in the sub study, the researchers will check the results of your first MRI scan, before you start hormone therapy. If they cannot see a nodule that they could target, you have hormone therapy, followed by standard radiotherapy.

But if they can clearly see a nodule, you have a transperineal template mapping biopsy under general anaesthetic.  During a transrectal ultrasound, the doctor takes biopsies through the skin between your penis and your anus (the perineum). They will put the gold seeds in place at the same time. You then start hormone therapy, followed by your radiotherapy planning and treatment as described above. Patients in this part of the study will also be offered a new type of PET scan using a radioactive tracer called choline (a Choline PET scan). This can further help to detect prostate cancer, but having the scan is optional.

The team will ask everybody taking part to fill out some questionnaires during the study and at follow up appointments. They will ask about any side effects you have had and about how you have been feeling. This is called a quality of life study.

Before you can join the study, you see the doctors and have some tests. The tests include

• Physical examination
• CT scan or MRI scan
• Bone scan
• Blood tests, including a PSA test

The first MRI scan will take 40 to 50 minutes, as you have some of the scan with the coil inside your back passage and some without the coil in place.

You have the gold seeds put in at the Fulham Road branch of the Royal Marsden Hospital. It takes between 15 and 30 minutes. If you have a transperineal template mapping biopsy, you also have this at Fulham Road. It takes about 40 minutes, but you have a general anaesthetic, so will be at the hospital for a bit longer to recover.

You have your radiotherapy planning session at the Sutton branch of the hospital.

You go to hospital every day for up to 7½ weeks for radiotherapy. You see the study team

• Every 2 weeks during radiotherapy
• After you finish radiotherapy and again 8 weeks later
• Then after 6 months, 1 year, 18 months and 2 years

Having gold seeds put in to your prostate gland can be uncomfortable.  If you wish, you can have some local anaesthetic. The gold seed markers are not removed after treatment and will not cause you any problems in the future.

As the study team will take X-rays each day to check the position of your prostate gland, taking part in the study will mean that you are exposed to more radiation. This could increase your risk of getting another cancer in the future. The amount of extra radiation is very small (about 2% of your treatment dose) and the study team thinks the risk is outweighed by the benefit of having your treatment planned accurately.

It is possible that men taking part in this study may have more radiotherapy side effects, but the researchers think this is unlikely.

We have more information about side effects of prostate cancer radiotherapy.