None listed
Conditions
Brief summary
Prostate cancer is the most commonly diagnosed cancer in Australia, making up 16% of all diagnosed cancers (excluding skin cancers). Fortunately, survival in prostate cancer is relatively good, with 84-88% of men living at least five years after diagnosis. Many men who are diagnosed with prostate cancer choose radical external beam radiation therapy (EBRT) for their treatment. EBRT is a radiation treatment usually given by one treatment per weekday over eight weeks. This treatment method offers very good treatment outcomes for controlling prostate cancer, however, it can produce some unwanted side effects. As most men who have EBRT live for at least 10-15 years after diagnosis, minimising these side effects is very important to offer the best quality of life to survivors. Diet invervention is a novel approach to solving one of the biggest challenges in prostate radiotherapy. The prostate gland constantly moves within the patient during radiotherapy because of its position close to the rectum. Changes in rectal filling is identified as the main cause of prostate movement. This movement means a larger volume must be treated to ensure all parts of the prostate receive enough radiation dose to cure the patient. Unfortunately treating a bigger area means healthy tissues next to the prostate such as the rectum and bladder also receive radiation dose. Irradiation of these organs is responsible for the sometimes debilitating side effects associated with radiotherapy. Short term side effects of treatment can include frequent and painful urination, diarrhoea and rectal discomfort. Long term side effects may include frequent, urgent and loose bowel motions, rectal bleeding and some may suffer from urinary incontinence. To reduce dose to these organs and to improve the dose delivery to the prostate they need to be kept stable during treatment. The aim of our study is to test the activity of a diet which is designed to keep the organ positions more consistent to see if it will reduce rectal variation. This has the advantage of empowering patients to be actively involved in their treatment. The study will utilise cone beam computed tomography (CBCT) scanning to assess prostate movement and rectal filling. This study will include 30 participants over 12 months who will be randomly assigned to either study arm. The study will change the diet of 15 patients receiving radiotherapy over the full course of their planning and treatment (about 11 weeks). To make a comparison we include 15 patients on the normal treatment arm who will eat their usual diet. All participants will record a diet diary so we can make sure the diet intervention arm follow their diet and also see what foods are being eaten in the normal diet which may produce bowel gas. CBCT scans will be taken on days 1 to 5 and then every second day for all participants. In this study we will assess if we can obtain reliable information about the rectum and prostate positions and their shape on all CBCT scans. We will then measure the difference of the organ positions between the diet intervention arm and the normal treatment arm and use this information to determine the sample size of a larger follow on study. We will also compare side effects and quality of life between the two study arms to see if there are any unexpected impacts associated with the diet intervention. If successful this study will follow on to a bigger study to see if the diet change is really better at keeping the prostate stable than eating a normal diet. The potential outcome for the studies will be a cheap, non-invasive method of reducing prostate movement during EBRT. This could improve the control of prostate cancer with EBRT and also reduce side-effects from the treatment. There is potential to further reduce the area treated to spare even more of the healthy tissue from radiation dose. The overall outcome would be to offer better quality of life to patients with prostate cancer who are treated with EBRT.
Interventions
Standard radical prostate radiotherapy of 74-78Gy in 37-39 daily fractions (5 times per week) over a period of 8 weeks. Two weeks prior to the treatment planning appointment participants will begin a dietary intervention of an antiflatulent diet and a psyllium supplement. The diet limits foods which are high in complex carbohydrates and supplements those foods with 20g of psyllium husk per day. The total duration of diet intervention will be around 11-12 weeks.
Sponsors
Peter MacCallum Cancer Centre
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
Male
Age
50 Years to No maximum
Healthy volunteers
No
Inclusion criteria
- Patients 50 years of age or older, eligible for External Beam Radiotherapy (EBRT) for prostate cancer to a dose of at least 74Gy in 37 fractions. - Biopsy proven adenocarcinoma of the prostate, International Union against Cancer (UICC) TNM Classification of Malignant Tumours 6th edition stages T1-T3b. - Patients who will successfully received gold seed implants. - Eastern Cooperative Oncology Group (ECOG) performance status 0-2. - Ability to understand and the willingness to sign a written informed consent document.
Exclusion criteria
- Patients receiving radical salvage therapy post-prostatectomy. - Patients with a history of Irritable Bowel Syndrome (IBS) - Patients with a history of constipation in the 6 months prior to diagnosis or receiving opiate analgesics. - Patients with a concurrent or previous malignancy within 5 years prior to randomisation. - Patients having received prior radiotherapy to the pelvis. - Patients with dietary or medical requirements that will prevent them following the prescribed diet. - Patients receiving any other investigational agents that may impact upon this study. - Patients with other uncontrolled concurrent illnesses, psychiatric illness or social circumstance that may limit compliance with this study. - Prosthesis that may inhibit the visibility of the seeds – and possibly the prostate on Cone Beam Computed Tomography (CBCT) images.
Outcome results
None listed