To optimize MRI protocols and processing techniques required for MRI guided radiotherapy on the MR-linac measured as signal to noise ratio, contrast, and acquisition time.
ID
Source
Brief title
Condition
- Other condition
Synonym
Health condition
Geen specifieke aandoening te benoemen. De ontwikkelde protocollen en beeldverwerkingstechnieken kunnen voor verschillende aandoeningen worden gebruikt.
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The optimized MRI protocols and processing techniques required for MRI guided
radiotherapy on the MR linac measured as signal to noise ratio, contrast, and
acquisition time.
Secondary outcome
na
Background summary
The MR-linac (MRL) is a hybrid machine which enables true image guided
radiotherapy. Image guidance of radiation treatment minimizes the uncertainties
about the location and shape of the tumor and surrounding organs at risk.
Therefore, margins to ensure tumor coverage can be reduced. This gives the
opportunity for dose escalation to the tumor and/or decrease the number of
fractions, which can result in reduction of the organs at risk dose, decreased
radiation-induced toxicity and better quality of life.
MR imaging in combination with radiation delivery requires technical
adjustments to both the MRI and the linac hard-ware to prevent interference of
the magnet on the linac and vice versa. For imaging, this means that we have to
deal with reduced gradient strength, which demands optimization of the
acquisition protocols. For the development of optimal MRI guided radiotherapy
strategies, images have to be acquired on the MR-linac. The hard-ware of the
MRI scanner installed in de MR-linac is different from a stand-alone MRI.
Therefore, scans have to be optimized and imaging strategies have to be tested.
During a treatment on the MR-linac MR images will be required in different
stages of the treatment: the pre-beam, beam-on and post-beam stage. In the
pre-beam phase, target definition, i.e. contouring (segmentation) of the tumor
and organs at risk, dose calculation, motion characterization is required. In
the beam-on phase motion target tracking and dose accumulation is performed,
while in the post-beam phase evaluation of the radiation treatment can be
tested. The current application deals with the pre-beam stage only.
Automatic segmentation of tumor and organs at risk needs images with a proper
contrast and signal to noise ration. In motion tracking, the challenge is to
image 3D volumes at a rate that is sufficient to track the tumor or gate the
dose delivery. Also for dose accumulation, rapid imaging is needed.
Additionally, the images need a high geometric accuracy. In the post beam
imaging, quantitative imaging will be used, that needs optimization on this new
hard-ware.
At this stage, several target regions have been defined for treatment
development on the MR-linac. The tumor sites consist of: bone metastases,
metastatic lymph nodes, rectum, prostate, esophagus, breast, pancreas, cervix,
brain, head and neck, lung. For all these reasons it*s essential to optimize
the dedicated scanning and image processing protocols for MR-linac.
Study objective
To optimize MRI protocols and processing techniques required for MRI guided
radiotherapy on the MR-linac measured as signal to noise ratio, contrast, and
acquisition time.
Study design
an observational study.
Study burden and risks
No benefits are expected for the volunteers.
No risks are known for healthy volunteers or patients undergoing MRI when they
are screened according to the MRI safety criteria. Participants will be scanned
during 45 to 90 minutes. A risk for subjects may be the finding of an
unexpected abnormality.
The sequences needed to visualize organs at risk will be tested on healthy
volunteers. Patients will only be asked if visualization of the tumor has to be
tested. Only patients with a WHO performance status of <= 2 will be asked.
Patient*s standard treatment will not be affected by the participation in this
study.
The study will result in dedicated MRI scanning procedures and image
processing techniques for patients to be treated on the MR-linac.
Heidelberglaan 100
Utrecht 3584 CX
NL
Heidelberglaan 100
Utrecht 3584 CX
NL
Listed location countries
Age
Inclusion criteria
In order to be eligible to participate in this study, a subject must meet all
of the following criteria:, - >= 18 years
- Capable and prepared to sign informed consent
- Healthy volunteers or cancer patients who will be or are treated at the
radiotherapy department, or patients with cancer at a stage or at a site that
is not routinely treated with radiotherapy, where the aim is that future
patients with a similar tumor stage or tumor site might be treated on the MRL.
Exclusion criteria
A potential subject who meets any of the following criteria will be excluded
from participation in this study:, - Contraindication for MRI scanning as
listed in screening form
- Neurological or psychiatric diagnosis
- MRI contraindications such as (possible) pregnancy and metal or electronic
implants not compatible with MRI
- Refusal of subjects to be informed of chance findings possibly relevant to
their health
- In case study participation would interfere with regular treatment
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL59820.041.17 |