Prostate CancerProsRSINCT04349501
Biomarker Monitoring of Prostate Cancer Patients With RSI MRI (ProsRSI)
A study testing Restriction Spectrum Imaging Magnetic Resonance Imaging in people with Prostate Cancer, run by University of California, San Diego at 1 site in United States.
Trial summary
Adult male patients with high-risk, localized prostate cancer and planning to undergo radiation therapy (RT) with androgen deprivation therapy (ADT) will undergo an advanced Magnetic Resonance Imaging (MRI) examination called Restriction Spectrum Imaging (RSI-MRI) to evaluate whether RSI-MRI can predict treatment… Read more about this study
- Who is it for?
- Ages 18 years and older, men only
- Conditions the study is for
- Prostate Cancer
- What is being tested?
- Restriction Spectrum Imaging Magnetic Resonance Imaging
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- 1 siteUnited States
- Study dates
- 29 Dec 2020to Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Male, aged ≥18 years, with histologically confirmed adenocarcinoma of the prostate
- High-risk prostate cancer (any of: PSA ≥20 ng/mL or cT3-T4 stage or Gleason score ≥8)
- Intended treatment and follow-up according to standard of care for prostate cancer
- Planning to undergo definitive radiotherapy with neoadjuvant and concurrent androgen deprivation therapy
- In good general health as evidenced by medical history and Eastern Cooperative Oncology Group (ECOG) performance status 0-2
- Provision of signed and dated informed consent form
- Stated willingness to comply with all study procedures and availability for the duration of the study
Who cannot join
- Prior radiotherapy to the pelvis
- Prior treatment for prostate cancer (cryotherapy, high frequency focused ultrasound, prostatectomy)
- Hip prosthesis
- Contraindication to MRI, per institutional requirements
- Technetium-99 bone scan showing no clear evidence of distant metastasis
- MRI or CT scan of the pelvis showing no clear evidence of bone or distant metastasis
- Another malignancy, unless in remission or unlikely to impact the patient's survival or ability to receive standard care for prostate cancer (e.g., cutaneous basal cell carcinoma)
- Patient has a history or current evidence of any condition, therapy, or laboratory abnormality that might confound the results of the trial, interfere with the subject's participation for the full duration of the trial, or is not in the best interest of the subject to participate, in the opinion of the treating investigator.
Trial locations and contacts
1 site in 1 country.
United States1 site
UCSD Moores Cancer Center
La Jolla, California, 92093
About this study
Official title: A Phase II Biomarker Study of Restriction Spectrum Imaging (RSI) MRI in Patients With High-Risk, Localized Prostate Cancer Who Will Receive Radiotherapy and Androgen Deprivation Therapy
Adult male patients with high-risk, localized prostate cancer and planning to undergo radiation therapy (RT) with androgen deprivation therapy (ADT) will undergo an advanced Magnetic Resonance Imaging (MRI) examination called Restriction Spectrum Imaging (RSI-MRI) to evaluate whether RSI-MRI can predict treatment response.
Read the detailed description
Participants will undergo RSI at three time points: before therapy (MRI #1), after neoadjuvant ADT (MRI #2), and after radiotherapy (MRI #3). Treatment response will be assessed primarily by absence of biochemical recurrence (PSA ≥2 ng/mL greater than nadir) within 3 years of completing radiotherapy. Change in RSI cellularity index from MRI #1 to MRI #2 will be evaluated for prediction of participants who will experience biochemical recurrence within 3 years, using area under the receiver operating characteristic curve. We hypothesize that RSI cellularity index will be an early biomarker for treatment effectiveness in prostate cancer treated with ADT and radiotherapy.
- Conditions
- Prostate Cancer
- Being tested
- Restriction Spectrum Imaging Magnetic Resonance Imaging
- Medical subject headings
- Prostatic Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Restriction Spectrum Imaging Magnetic Resonance ImagingOther
Also called RSI-MRI
RSI is a multicompartment model of diffusion MRI that uses data acquired at multiple b-values to distinguish varied diffusion speeds (restricted intracellular, hindered extracellular, and approximately free diffusion).
| Study group | Role | What they receive |
|---|---|---|
| RSI-MRI | Experimental | Participants will undergo RSI-MRI at three time points: before androgen deprivation therapy (ADT); after neoadjuvant ADT but before radiation therapy (RT); and after RT. Receives: Other: Restriction Spectrum Imaging Magnetic Resonance Imaging |
What is being measured
The primary outcome is the main question the study is designed to answer.
Biochemical recurrence (PSA 2 ng/mL greater than nadir) within 3 years of completing RT.
To evaluate the performance of the RSI cellularity index before and during therapy as a biomarker to identify participants who will experience biochemical recurrence within 3 years post-radiotherapy.
Measured: within 3 years of RT completion
Secondary outcomes (1)
PSA nadir within the 18 months after RT ≥0.5 ng/mL.
To evaluate the performance of the RSI cellularity index for identifying participants who will fail to reach a PSA nadir <0.5 ng/mL within 18 months of RT.
Measured: within 18 months of RT completion
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Apr 2020
- Study start29 Dec 2020
- Primary completionDec 2026 (estimated)
- Study completionDec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Prostate CancerStudies of the same condition, open and under way.
- More trials run by University of California, San DiegoThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- A logistic regression model of biochemical recurrence within 3 years will be fit, using maximum likelihood, on the change in RSI cellularity index from MRI #1 to MRI #2 and relevant covariates such as demographics. Continuous variables will be splined; only main effects will be considered. The cross-validated Area Under the Curve (AUC) for this model will be reported with a 95% bootstrap confidence interval using Efron's bias-corrected and accelerated (bca) method. If the lower bound on the 95% confidence interval of the Area Under the Curve (AUC) excludes 0.55, RSI cellularity index will be declared "viable" for identifying participants who will recur within the three-year post treatment. If declared "viable", a Cox model for predicting recurrence time will be fit, and the hazard ratios for RSI will be used to describe the adjusted associations supported by the data between RSI cellularity index and recurrence time.
- Masking
- None (open label)
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, San Diego
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Tyler Seibert, University of California, San Diego
- Investigators
- Tyler Seibert, MD, PhD, Principal investigator, University of California, San Diego
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04349501
- Sponsor's protocol ID
- 200266
- Acronym
- ProsRSI
- Status last verified
- Nov 2025
- First submitted
- 14 Apr 2020
- Last updated
- 5 Nov 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase II Biomarker Study of Restriction Spectrum Imaging (RSI) MRI in Patients With High-Risk, Localized Prostate Cancer Who Will Receive Radiotherapy and Androgen Deprivation Therapy
- ClinicalTrials.gov ID
- NCT04349501
- Acronym / sponsor ID
- ProsRSI / 200266
- Conditions
- Prostate Cancer
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- University of California, San DiegoUniversity, hospital or other
- Study start
- 29 Dec 2020 (actual)
- Primary completion
- Dec 2026 (estimated)
- Study completion
- Dec 2026 (estimated)
- First posted
- 16 Apr 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Adult male patients with high-risk, localized prostate cancer and planning to undergo radiation therapy (RT) with androgen deprivation therapy (ADT) will undergo an advanced Magnetic Resonance Imaging (MRI) examination called Restriction Spectrum Imaging (RSI-MRI) to evaluate whether RSI-MRI can predict treatment response.
Detailed description
Participants will undergo RSI at three time points: before therapy (MRI #1), after neoadjuvant ADT (MRI #2), and after radiotherapy (MRI #3). Treatment response will be assessed primarily by absence of biochemical recurrence (PSA ≥2 ng/mL greater than nadir) within 3 years of completing radiotherapy. Change in RSI cellularity index from MRI #1 to MRI #2 will be evaluated for prediction of participants who will experience biochemical recurrence within 3 years, using area under the receiver operating characteristic curve. We hypothesize that RSI cellularity index will be an early biomarker for treatment effectiveness in prostate cancer treated with ADT and radiotherapy.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- A logistic regression model of biochemical recurrence within 3 years will be fit, using maximum likelihood, on the change in RSI cellularity index from MRI #1 to MRI #2 and relevant covariates such as demographics. Continuous variables will be splined; only main effects will be considered. The cross-validated Area Under the Curve (AUC) for this model will be reported with a 95% bootstrap confidence interval using Efron's bias-corrected and accelerated (bca) method. If the lower bound on the 95% confidence interval of the Area Under the Curve (AUC) excludes 0.55, RSI cellularity index will be declared "viable" for identifying participants who will recur within the three-year post treatment. If declared "viable", a Cox model for predicting recurrence time will be fit, and the hazard ratios for RSI will be used to describe the adjusted associations supported by the data between RSI cellularity index and recurrence time.
| Arm | Type | Receives |
|---|---|---|
| RSI-MRI | Experimental | Other: Restriction Spectrum Imaging Magnetic Resonance ImagingParticipants will undergo RSI-MRI at three time points: before androgen deprivation therapy (ADT); after neoadjuvant ADT but before radiation therapy (RT); and after RT. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Male, aged ≥18 years, with histologically confirmed adenocarcinoma of the prostate
- High-risk prostate cancer (any of: PSA ≥20 ng/mL or cT3-T4 stage or Gleason score ≥8)
- Intended treatment and follow-up according to standard of care for prostate cancer
- Planning to undergo definitive radiotherapy with neoadjuvant and concurrent androgen deprivation therapy
- In good general health as evidenced by medical history and Eastern Cooperative Oncology Group (ECOG) performance status 0-2
Key exclusion criteria (8 listed)
- Prior radiotherapy to the pelvis
- Prior treatment for prostate cancer (cryotherapy, high frequency focused ultrasound, prostatectomy)
- Hip prosthesis
- Contraindication to MRI, per institutional requirements
- Technetium-99 bone scan showing no clear evidence of distant metastasis
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Restriction Spectrum Imaging Magnetic Resonance ImagingAlso: RSI-MRIRSI is a multicompartment model of diffusion MRI that uses data acquired at multiple b-values to distinguish varied diffusion speeds (restricted intracellular, hindered extracellular, and approximately free diffusion). | Other | RSI-MRI |
Primary outcome
Biochemical recurrence (PSA 2 ng/mL greater than nadir) within 3 years of completing RT.
Time frame: within 3 years of RT completion
To evaluate the performance of the RSI cellularity index before and during therapy as a biomarker to identify participants who will experience biochemical recurrence within 3 years post-radiotherapy.
1 secondary outcome
PSA nadir within the 18 months after RT ≥0.5 ng/mL.
Time frame: within 18 months of RT completion
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Nov 2025.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Tyler Seibert, MD, PhD principal investigator
University of California, San Diego
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Restriction Spectrum Imaging Magnetic Resonance Imaging in people with Prostate Cancer, run by University of California, San Diego at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 5 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Biochemical recurrence (PSA 2 ng/mL greater than nadir) within 3 years of completing RT. (time frame: within 3 years of RT completion). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Nov 2025.