Multiparametric MRI for Assessing Radiotherapy Treatment Response of Prostate Cancer
Twenty patients who are diagnosed with prostate cancer and will undergo external beam
radiotherapy will be recruited in this study. Three MR scans of each patient under the study
will be performed at different time points. Each MR scan will include several advanced MR
imaging sequences (including but not limited to MR spectroscopy, diffusion and perfusion
imaging, which are used in routine clinical radiology settings) in addition to typical T1
and T2 weighted MR imaging. The MR scans will be conducted at Radiation Oncology department
with the position similar to the treatment position.
The first MR scan will happen prior to the radiation treatment during the scheduled patient
simulation for baseline information. The T1- and T2-weighted MRI will be used for
delineation of prostate gland as a part of routine treatment planning process. Additional
functional MR (DWI/ADC. DCE, etc) images will be used as baseline of this study. The second
MR scan with the same sequences will happen in the mid course of radiation treatment. And
the third MR scan with the same sequences will happen at end of radiation treatment. Because
the participated patients will come to radiation oncology department daily for their routine
radiation treatment there will be no additional visits required for patients. The first scan
will happen during the same day when patients undergo CT and MRI simulation for treatment
planning as part of their standard cares. Two extra MRI scans will be performed as part of
this research protocol. The second and third scans will happen on one of treatment days.
While it is anticipated that the advanced MRI techniques will eventually play an important
role in the early intervention of radiation treatment and patient management of radiotherapy
of prostate cancer at JHH, no modification of the radiation treatment and patient management
will be based on the imaging information acquired during this feasibility study. All
participated patients will undergo the routine radiation treatment as all other prostate
cancer patients managed in our department.
The imaging data acquired will be systematically processed and analyzed along with
correlating to radiation treatment dose distribution. All MRI data from three different
scans need to be registered to each other and then register to planning CT. The anatomical,
functional changes of tumor and normal tissues during radiation treatment will be accessed
and correlated to radiation dose. After radiotherapy, all enrolled patients will be
followed up the same way as normal post treatment management. The short term or long term
tumor response and normal tissue side effects will also be collected under routine clinical
Following MRI based biomarker will be assessed:
- ADC map
- Dynamic contrast imaging (DCE)
- Other MRI modalities as they are developed For example, tumor size measurement, MRI
parameters of choline peak in spectroscopy, ADC values, and DCE map, tumor and normal
tissue doses will be recorded for each scans. A multi-parametric analysis will be
performed to seek correlations.
A new software package will be developed to help overlay the functional MRI data on top of
3D radiation dose distribution. The region of interests and the correlations between MRI
data and dose will be easier to identified using under the new software. Further detail
quantitative analysis can then be focused on those identified regions of interest.
Data Analysis Steps:
1. After first scan, dynamic contrast enhanced (DCE) MRI data will be processed by iCAD
package to get pharmacokinetic parameters e.g. Ktrans and Ve.. A Ktrans vs Ve map will
be generated. All MRI data including T1, T2, ADC map, DEC map, spectroscopy will be
resampled to same resolution and registered to each other. The treatment target,
prostate in this case, along with surrounding normal organs (rectum, urethral and
bladder) will be delineated based on anatomical MRI images. Within prostate gland,
different part of regions, cancerous or healthy regions based on functional MRI will be
2. Second and third sets of MRI scan data will be processed the same way as the Step 1 and
registered to baseline scan. Same anatomical structures and same regions within
prostate will be defined.
3. To test Hypothesis one, the MRI signal from the second and third scan will be compared
to the baseline scan on each individual MRI sequence data and on combined all data in a
multiparametric approach.The signal changes within different organs and different
regions of prostate will be analyzed. A statistical significant (p<0.05) signal
intensity changes within certain regions of interest can be defined as observation of
After kinetic and other MRI data analysis are done independently without the knowledge
of the radiation dose, all registered MRI data will be imported into radiation
treatment planning system. Some special software will be developed to change the some
MRI data format to a recognized format for planning system. Within the treatment
planning system, the MRI data will be co-registered to planning CT. The 3D dose
distribution can then overlap on MRI data. The dosimetric information like maximum
dose, mean dose of each organ or region of interest defined in previous steps will be
calculated. The dose parameters will be calculated from stationary planning CT. There
is potential dose uncertainty due to motion of prostate and rectum. However, given that
external beam radiotherapy of prostate usually lasts 6-8 weeks with many fractionated
treatments and image guided patient treatment ability in our clinic, the systematic
organ motion is very small. Besides, most of the literature data on dose dependent
tumor control and toxicity were derived from planning CT without considering organ
motion. Therefore, we will not consider the effect of organ motion and use the dose
parameters from stationary planning CT in this protocol.
4. The correlation between the dosimetric parameters and the signal changes will be
analyzed to test the Hypothesis two.
5. Routine follow up data on tumor response (e.g PSA value) and normal tissue toxicity
assessment will be collected. Although with the limited sample size of this pilot
study, the direct link between MRI signal changes and treatment outcome may not be
obtained. Any information, trend gathered from the correlation can be used to design
next phase study.
Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Diagnostic
MRI use to predict treatment response
To study the feasibility of using magnetic resonance imaging (MRI) to predict treatment response in patients with prostate cancer undergoing radiation therapy. The anatomical, functional, and location changes in tumor or normal tissues during the radiation will be assessed and correlated with MRI data and treatment dose. Hypothesis one: Functional or anatomical MRI signal changes during the radiotherapy can be used as predictors to assess treatment response. We anticipate observing dose dependent MRI signal changes during the radiation treatment.
Danny Song, M.D.
The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins
United States: Institutional Review Board
|The Sidney Kimmel Comprehsensive Cancer Center at Johns Hopkins||Baltimore, Maryland 21287|