Metastatic Castration-resistant Prostate CancerEarly Phase 1NCT07609225
Chemical-Shift-Encoded MRI for Active Bone Marrow Dosimetry in Radiopharmaceutical Therapy
A Early Phase 1 study testing 3'-Deoxy-3'-[18F]-fluorothymidine and Chemical-shift-encoded MRI in people with Metastatic Castration-resistant Prostate Cancer, run by University of Wisconsin, Madison at 1 site in United States.
Trial summary
This study compares two different imaging procedures to each other, one using positron emission tomography (PET) with fluorothymidine F-18 (FLT) (FLT PET for short), and the other using chemical shift-encoded (CSE) magnetic resonance imaging (MRI) or CSE-MRI for short, to determine specifically if CSE-MRI is as… Read more about this study
- Who is it for?
- Ages 18 years and older, men only
- Conditions the study is for
- Metastatic Castration-resistant Prostate Cancer
- What is being tested?
- 3'-Deoxy-3'-[18F]-fluorothymidine and Chemical-shift-encoded MRI
- Type of treatment
- Injection or infusion, Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteUnited States
- Study dates
- 16 Oct 2026to Sep 2029
- Phase
- Early Phase 1
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
- Ability to understand and the willingness to sign a written informed consent document.
- Patients must be informed of the experimental nature of the study and its potential risks, and must sign institutional review board (IRB) approved consent form indicating such understanding.
- Individuals at least 18 years of age.
- Patients must have histologically or cytologically confirmed prostate cancer.
- Patients must be clinically deemed appropriate for standard of care Lu-177 PSMA RPT.
- Eastern Cooperative Oncology Group (ECOG) performance 0-2
- Patients must be able to comply with all study procedures, including having both the ability and willingness to lie flat for ≥ 30 minutes during imaging.
Who cannot join
- Patients receiving any concurrent therapy known to impact bone marrow (either stimulate or suppress the marrow, for example G-CSF).
- Patients treated with chemotherapy or 223Ra radiotherapy within 4 weeks.
- All acute toxic effects of any prior therapy (including surgery, radiation therapy, chemotherapy) must have resolved to a grade ≤ 2 according to National Cancer Institute Common Terminology Criteria for Adverse Events Version 5 (CTCAE).
- Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements per treating physician discretion.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Wisconsin Carbone Cancer Center
Madison, Wisconsin, 53792
About this study
This study compares two different imaging procedures to each other, one using positron emission tomography (PET) with fluorothymidine F-18 (FLT) (FLT PET for short), and the other using chemical shift-encoded (CSE) magnetic resonance imaging (MRI) or CSE-MRI for short, to determine specifically if CSE-MRI is as accurate as FLT PET in telling the difference between active and inactive marrow. The best way to do the comparison between the two imaging procedures is if they are done at the same time on the same patient. This is possible with use of a scanner at the University of Wisconsin Hospitals and Clinics (UW Health), the GE SIGNA PET/MR scanner. The prediction is that CSE-MRI as accurate as FLT at telling the difference between active and inactive marrow in patients with metastatic prostate cancer, and that is the primary reason for this study. 15 participants will be enrolled and on study for up to 14 months.
Read the detailed description
This single-site, single-arm study will evaluate the accuracy of active bone marrow (ABM) segmentation with CSE-MRI by comparing to the established technique of FLT PET in patients with PSMA+ mCRPC who are scheduled to receive Lutetium-177 Prostate-Specific Membrane Antigen (177Lu-PSMA) (PLUVICTO®) Radiopharmaceutical Therapy (RPT) as standard of care. All standard of care testing, monitoring, and administration for 177Lu-PSMA RPT (PLUVICTO®) will be followed for this study.
Participants will receive 177Lu-PSMA RPT (PLUVICTO®) for a total of 6 doses, or until disease progression or unacceptable toxicity. Doses of 177Lu-PSMA RPT will be given at least 6 weeks apart. At the discretion of the prescribing physician, standard of care PSMA PET/MRI will be performed at any time during cycles 2-4, and also within 6 months of the final administration of 177Lu-PSMA RPT; during these scans, the CSE-MRI will also be acquired. Participants will be followed for 6 months following the final administration of 177Lu-PSMA RPT.
The primary endpoint is a calculation of the mean Dice similarity coefficient (DSC) between active bone marrow volumes derived from CSE-MRI and ¹⁸F-FLT PET across all enrolled patients. A mean DSC of ≥0.7 will indicate that CSE-MRI is a clinically acceptable alternative to FLT PET for identifying ABM.
With the exception of the research-related CSE-MRI and FLT PET scans, all assessments, laboratory tests, RPT, and imaging scans are standard of care.
- Being tested
- 3'-Deoxy-3'-[18F]-fluorothymidine, Chemical-shift-encoded MRI
- Keywords
- FLT PET, CSE-MRI, active bone marrow, mCRPC
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
3'-Deoxy-3'-[18F]-fluorothymidineDrug
Also called FLT, 18F-FLT
Within 29 days prior to 177Lu-PSMA RPT, participants will undergo 18F-FLT PET to assess proliferating bone marrow and CSE-MRI to generate a fat fraction map on a GE SIGNA PET/MR scanner. This is expected to last 2-3 hours.
FLT injections will be administered one hour before imaging for tracer uptake. Participants will receive an IV injection of up to 10 mCi (370 MBq) of 18F-FLT.
The patient will receive 1 CSE-MRI/FLT PET scan prior to the start of therapy.
Chemical-shift-encoded MRIDevice
Also called CSE-MRI
Within 29 days prior to 177Lu-PSMA RPT, participants will undergo 18F-FLT PET to assess proliferating bone marrow and CSE-MRI to generate a fat fraction map on a GE SIGNA PET/MR scanner. This is expected to last 2-3 hours. The patient will receive 1 CSE-MRI/FLT PET scan prior to the start of therapy.
Up to 3 CSE-MRI scans will be completed as part of this study. At the physician's discretion, a single standard of care (SOC) mid-treatment PSMA PET/MRI can be performed any time during cycles 2-4, and a SOC post-treatment can be done within 6 months of final treatment. CSE-MRI will be acquired during these scans.
| Study group | Role | What they receive |
|---|---|---|
| Participants scheduled to receive 177Lu-PSMA | Experimental | Males aged 18 years and older with metastatic PSMA-positive castration-resistant prostate cancer (CRPC) who are scheduled to receive 177Lu-PSMA (PLUVICTO®).
Within 7 days prior to 177Lu-PSMA RPT, participants will receive an injection of FLT and then undergo a FLT PET to assess proliferating bone marrow and CSE-MRI to generate a fat fraction map on a GE SIGNA PET/MR scanner. Whole-body single photon emission computed tomography (SPECT/CT) imaging (2-3 bed positions) will be performed per standard of care on Day 0 (3 +/- 2 h), Day 1 (24 +/- 4 h), and Day 4 (96 +/- 24 h) post-177Lu-PSMA RPT infusion. As standard of care, participants will receive up to 6 infusions of 177Lu-PSMA RPT every 6 weeks at UW Health. Receives: Drug: 3'-Deoxy-3'-[18F]-fluorothymidine; Device: Chemical-shift-encoded MRI |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean Dice similarity coefficient (DSC)
The mean Dice similarity coefficient (DSC) between active bone marrow volumes derived from CSE-MRI and ¹⁸F-FLT PET across all enrolled patients. A mean DSC of ≥0.7 will indicate that CSE-MRI is a clinically acceptable alternative to FLT PET for identifying ABM
Measured: up to 14 months
Secondary outcomes (4)
Difference in Mean Tumor Absorbed Dose (Gy)
Difference in mean tumor absorbed dose (Gy) across three lesion-segmentation methods, with segmentation performance characterized by DSC relative to physician manual contours.
Measured: up to 14 months
Variance in Tumor and Bone Marrow Volume
Repeatability will be measured by variance in tumor and bone marrow volumes.
Measured: up to 14 months
Variance in Tumor and Bone Marrow Doses
Repeatability will be measured by variance in tumor and bone marrow doses
Measured: up to 14 months
Difference in Mean Absorbed Dose (Gy)
Difference in mean absorbed dose (Gy) between conventional and CSE-MRI-based ABM dosimetry methods
Measured: up to 14 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 May 2026
- Study start16 Oct 2026
- Primary completionSep 2029 (estimated)
- Study completionSep 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Metastatic Castration-resistant Prostate CancerStudies of the same condition, open and under way.
- 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
- Early Phase 1
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 15 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Wisconsin, Madison
- Sponsor type
- University, hospital or other
- Collaborators
- GE Healthcare
- Responsible party
- Sponsor
- Investigators
- Michael Lawless, PhD, Principal investigator, UW School of Medicine and Public Health
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07609225
- Sponsor's protocol ID
- 2026-0693
- Other IDs
- Protocol Version, SMPH / Human Oncology, UW26012
- Status last verified
- Oct 2026
- First submitted
- 20 May 2026
- Last updated
- 23 Oct 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- Yes
- Individual data sharing
- Yes