A Study Using MRI To Assess Bladder Motion During Radiotherapy
Research type
Research Study
Full title
A pilot study using Magnetic Resonance Imaging (MRI) to assess bladder motion during radiotherapy treatment.
IRAS ID
240130
Contact name
Yee Pei Song
Contact email
Sponsor organisation
University of Manchester
Clinicaltrials.gov Identifier
Duration of Study in the UK
1 years, 4 months, days
Research summary
Summary of Research
The options for curing bladder cancer (that invades the muscle layers, but not spread to other organs) are surgery to remove the whole bladder or tri-modality treatment (TMT) where patients do not have their bladders removed. TMT involves surgery to remove the tumour from the bladder, followed by chemotherapy and radiotherapy treatments.Radiotherapy treatment is planned by doctors using pictures from a single computed tomography (CT) scan taken before starting treatment. It is difficult to see where the tumour used to be (tumour bed) on CT scans. The bladder can move and/or expand, and the other pelvic organs such as the large bowels or genitalia can change position during the course of treatment. This means that the whole bladder has to be treated with the same dose of radiation and a large margin is allowed around the bladder to ensure that parts of the bladder is not missed even if it moves from the original position. This increases the risk of long-term side effects.
There have been some studies looking at the movement and expansion of the bladder during radiotherapy and different ways of adapting radiotherapy treatment. These have included changing the margins based on individual changes, creating two or more different radiotherapy plans and choosing the best plan each day (“plan of the day”), and other techniques. These studies have been carried out using a type of scan called a cone beam computed tomography (CBCT) which gives poor quality images. Magnetic Resonance Imaging (MRI) scans allow doctors to visualise the bladder and other structures more effectively. Studies have also shown that doctors can more accurately identify the tumour bed on MR scans.
This study will explore the role of MRI in adaptive radiotherapy for bladder cancer and will test the development of different treatment strategies.
Summary of Results
This study included patients diagnosed with muscle-invasive bladder cancer treated with curative chemoradiotherapy. Muscle-invasive bladder cancer means that the cancer cells have spread beyond the inner lining of the bladder and into the muscle layer. Patients had weekly MRI scans during treatment. The MRI scans included images to detail a patient's anatomy – with full and empty bladder as well as cine data (with a scan every minute for 10 minutes) to measure movement during the time taken for an individual radiotherapy treatment. They also included a Diffusion Weighted Imaging sequence (a special kind of MRI sequence which tests tissue permeability) which was used to study if the scans can predict response. 13 (12 males, 1 female) patients were recruited to the study from July 2018 to June 2019. Three patients withdrew from the study due to medical reasons. Change in bladder volume is associated to the change in tumour bed volume and tumour bed thickness. The bladder is a highly mobile organ. Understanding the association between tumour bed and bladder motion allows the production of a library of radiotherapy plans to account for the different shape and position of the bladder from day to day.REC name
North West - Greater Manchester East Research Ethics Committee
REC reference
18/NW/0352
Date of REC Opinion
7 Jun 2018
REC opinion
Further Information Favourable Opinion