A trial looking at high pressure oxygen for radiotherapy side effects (HOT II)

Who can enter

You can enter this trial if you

• Had cancer in the past that had not spread outside the pelvis (this includes rectal cancer, prostate cancer, testicular cancer, bladder cancer, cervical cancer, womb cancer, vaginal cancer, vulval cancer and ovarian cancer)
• Had radiotherapy at least 12 months ago
• Have no signs of cancer now
• Have bowel problems caused by your radiotherapy and they have not improved with medication or changes in lifestyle
• Are well enough for hyperbaric oxygen therapy
• Are at least 18 years old

You cannot enter this trial if you

• Have had surgery for rectal cancer
• Have had hyperbaric oxygen therapy before
• Have had a chemotherapy drug called bleomycin before
• Have a fear of small spaces (claustrophobia)
• Have epilepsy
• Have serious breathing problems or a medical condition that affects your lungs
• Have had an operation on your ears in the past, except to drain fluid from the ear (grommets), or you have problems with the pressure in your ears
• Are not able to have an MRI scan (have metal clips in your body or a pacemaker for example)

Trial design

This trial is a randomised trial. It will recruit 75 people into 2 groups. The people taking part are put into treatment groups by a computer. Neither you nor your doctor will be able to decide which group you are in, or be told which group you are in. This is called a double blind trial. If you are in group 1 you will have 100% oxygen under pressure. If you are in group 2 you will have 21% oxygen (air) under pressure.

For every 3 people taking part, 2 will have 100% oxygen and 1 will have 21% oxygen.

Everyone will go to one of the specialist centres taking part in this study to have hyperbaric oxygen therapy (HBO). You go every day, 5 days a week, (Monday to Friday) for 8 weeks. Each treatment takes about an hour and a half.

To have HBO, you sit inside a chamber on your own or with up to 5 other patients and a qualified attendant, depending on the size of the chamber at the specialist centre. The chamber is sealed, but has small windows. There is a doctor just outside the whole time.

Once you are in the chamber, the air is compressed. You breathe in 100% (or 21%) oxygen from a see-through hood for 30 minutes at a time, with a 5 minute break in between. After treatment finishes, the air is slowly decompressed to normal pressure. You can then go home. If you have any problems while you are in the chamber, the compression or decompression will be stopped.

You fill out a couple of questionnaires before you start treatment and every 3 months for the following 12 months. One will ask you about how you have been feeling and about any problems you have had. It is called a quality of life questionnaire. The other will be looking at the costs of this treatment for you and the NHS. This is called a health economics questionnaire.

Hospital visits

Before you can start the study, you will see a bowel specialist. They will ask you about the long term side effects of radiotherapy and how it affects your daily life. They may suggest other ways to improve your symptoms, which you must try before taking part in this trial. If this treatment or advice helps, then you will no longer be able to take part.

If you are able to take part in this study, you will see the research team in London for some tests to check what effect the radiotherapy has had on your bowel. You will have

• A sigmoidoscopy
• A sample of tissue (biopsy) taken from your rectum (except if you have had brachytherapy for prostate cancer)

You also have these tests 2 weeks after treatment finishes and 12 months after you start treatment. The research team will use these tissue samples to learn more about the long term side effects of radiotherapy and how HBO treatment works.

If you are not able to attend the Royal Marsden Hospital in London for the tests, the trial team may be able to arrange for you to have a sigmoidoscopy at your local hospital (if you have not had one in the last year), and for a specialist nurse (Clinical Nurse Practitioner) to assess you by telephone.

You may also need to have an MRI scan.

To have HBO treatment, you will have to travel to one of the following specialist centres in

• Cardiff
• Chichester
• Great Yarmouth
• Hull
• London
• Plymouth
• Poole
• Rugby
• Wirral

Side effects

Side effects of hyperbaric oxygen therapy include

• Tiredness
• Mild changes in vision (until 6 to 12 weeks after treatment)
• Ear pain or damaged (ruptured) ear drum - this usually heals within a week
• Fits (seizures) - this is very rare
• Gas bubbles entering the bloodstream causing symptoms similar to a stroke or heart attack (this is also very rare)