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Trial Title:
Evaluation of Ultrasound Probe for Use in Bladder Radiotherapy
NCT ID:
NCT01698359
Condition:
Bladder Cancer
Conditions: Official terms:
Urinary Bladder Neoplasms
Study type:
Observational
Overall status:
Unknown status
Study design:
Time perspective:
Prospective
Summary:
Muscle-invasive bladder cancer affects over 3,000 new patients in the UK each year and
radiotherapy comprises a key part of the treatment pathway for many of them. Bladder
radiotherapy in the UK involves delivery of radiation to the entire bladder volume and
aims to deliver a high dose to the bladder while sparing nearby healthy organs (e.g. the
bowel). Unfortunately, large variations in bladder shape and volume are observed
throughout treatment that compromise the probability of a positive outcome for the
patient, either by increasing the risk of side-effects or by reducing the likelihood of
adequately treating the disease.
In recent years, the implementation of 'adaptive' bladder radiotherapy strategies has
increased. These techniques allow modification of the treatment based on the observed
variations in bladder shape and volume. However, these strategies often rely on daily
X-ray imaging of the patient prior to treatment, which is time-consuming and associated
with a small risk of inducing a cancer in the patient.
This study will evaluate the potential of a commercially available ultrasound probe for
use as an alternative to X-ray scanning during treatment for these patients. The study
will also aim to compare the likelihood of reducing side-effects and successfully
treating the disease for the different adaptive strategies that are used around the
world.
Detailed description:
All experiments and data analysis will be performed in the Magnetic Resonance Imaging
(MRI) and Radiotherapy departments respectively, at the Queen Elizabeth Hospital.
Five volunteers will be recruited to this study. They will each be required to follow a
documented drinking protocol prior to each of three scan sessions. The drinking protocol
is specific to this study and will not be intended for use with patients. To address the
primary endpoint of the study (i.e. the precision of the ultrasound probe for measurement
of bladder volume), measurement of a wide range of bladder volumes is required. In order
to address this aim while making efficient use of the limited available MRI scanner time,
the drinking protocol has been designed such that the volunteer will begin each scan
session with an empty bladder and finish it with a full bladder. To this end, each
volunteer will be required to void their bladder upon arrival and then consume 500ml of
water immediately prior to the start of the scan session.
Each volunteer will then be positioned on the scanner couch according to the same
protocol used for patients and alternate MRI and ultrasound scans will then be acquired.
Given the time required for each scan it is anticipated that five MRI scans and fifteen
ultrasound scans (three scans at a time to reduce the noise on the results, i.e.
ultimately giving five ultrasound bladder volume measurements) will be acquired in each
session. Each volunteer will be asked to attend for three sessions over the course of a
number of weeks so that the repeatability of bladder filling patterns can be determined.
Data processing and analysis
The volume measurements from the ultrasound probe will be recorded and each of the MRI
images will be exported to the Radiotherapy department where the bladder volume will be
determined. The precise timings of all scan acquisitions will be recorded during the
imaging session. Bladder volumes measured by the ultrasound probe, which can be read
instantly, will be recorded during the session. To evaluate the primary endpoint, the
precision and accuracy of the ultrasound probe will be quantified by comparing the
measured values to those expected from the MRI volumes. Each volume measurement from the
MRI scans will be checked by a second observer to minimise any associated researcher
error.
To evaluate the secondary endpoint, the imaging protocol described above will provide up
to 15 MRI images for each volunteer that can be used to inform a comparison of the
different adaptive strategies. However, since patients are always asked to empty their
bladder prior to radiotherapy treatment (in order to minimise the volume that receives
radiation), the deliberately wide-ranging bladder volumes that will have been measured in
this study will not be representative of those that would be observed in clinical
practice. To address this problem, a suitable dataset that quantifies the distribution of
bladder volumes encountered in a typical patient cohort will be used (Christie dataset,
permission obtained.Software will be written to randomly assign a bladder volume to each
day of each volunteer's 'treatment'. The MRI scan from that volunteer that most closely
corresponds to the selected volume will then be assigned for that day's treatment. This
will be repeated for the full 20 days of treatment and the importance of each MRI scan
can then be factored into the results analysis accordingly.
The treatment planning system within the Radiotherapy department will then be used with
the MRI scans to simulate a range of different 'treatments' according to each of the
different adaptive bladder radiotherapy strategies to be compared. The different
strategies are summarised here:
- Conventional strategy: This is the current standard treatment, in which the patient
plan is prepared based on an initial CT scan of the patient with an empty bladder
and no account is made of subsequent daily variations in bladder shape and volume.
- Plan-of-the-day strategy: Based on an initial CT scan of the patient with an empty
bladder, three different treatment plans are created based on an assumption of how
the bladder might expand. These are intended to simulate empty, partially full and
full bladders. The patient is scanned before treatment each day and the most
appropriate plan is selected for treatment.
- Dynamic strategy: Three different treatment plans are created based on a series of
initial CT scans of the patient with empty, partially full and full bladder. These
would be expected to directly represent the empty, partially full and full bladders
for the individual patient. The patient is scanned before treatment each day and the
most appropriate plan is selected for treatment.
- Composite strategy: The patient is CT scanned with an empty bladder and treated
according to the Conventional strategy for the first 7 days of treatment with daily
imaging. The first 5 daily scans of the patient are used to generate plans based on
small, partially full and full bladder. From the 8th day of treatment the daily
image is used to select which of these plans is appropriate for treatment.
Data processing of the MRI scans will be carried out retrospectively. The MRI scans will
be anonymised and exported to the Radiotherapy department. The data will then be used to
(i) acquire bladder volume information to compare with that acquired from the ultrasound
probe and (ii) prepare and evaluate radiotherapy treatment simulations to investigate the
benefits of different adaptive bladder radiotherapy strategies
Comparison of different adaptive techniques will focus on how much radiation is received
by the bowel and the extent to which the radiation misses the disease on any day of
treatment.
Criteria for eligibility:
Study pop:
Healthy volunteers from within the staff of the Radiotherapy, Medical Physics and
Oncology departments at the Queen Elizabeth Hospital
Sampling method:
Non-Probability Sample
Criteria:
Inclusion Criteria:
- Healthy volunteers
Exclusion Criteria:
- Pre-existing bladder conditions
Gender:
All
Minimum age:
N/A
Maximum age:
N/A
Healthy volunteers:
Accepts Healthy Volunteers
Locations:
Facility:
Name:
University hospital Birmingham
Address:
City:
Birmingham
Zip:
B15 2TH
Country:
United Kingdom
Investigator:
Last name:
Anjali Zarkar, FRCR MD MBBS
Email:
Principal Investigator
Start date:
November 2012
Completion date:
October 2013
Lead sponsor:
Agency:
University Hospital Birmingham NHS Foundation Trust
Agency class:
Other
Source:
University Hospital Birmingham NHS Foundation Trust
Record processing date:
ClinicalTrials.gov processed this data on November 12, 2024
Source: ClinicalTrials.gov page:
https://clinicaltrials.gov/ct2/show/NCT01698359