Recruiting
Early Phase 1

FLT PET vs. CSE-MRI

Sponsor:

University of Wisconsin, Madison

Code:

NCT07609225

Conditions

Metastatic Castration-resistant Prostate Cancer

Eligibility Criteria

Sex: Male

Age: 18+

Healthy Volunteers: Not accepted

Interventions

3'-Deoxy-3'-[18F]-fluorothymidine

Chemical-shift-encoded MRI

Study Details

Brief 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 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.

Conditions

Metastatic Castration-resistant Prostate Cancer

Study ID

NCT07609225

Start date

Oct 16, 2026

Status verified date

Oct, 2026

Completion date

Sep, 2029

Anticipated

Primary completion date

Sep, 2029

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Male

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • 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.

Exclusion Criteria:

  • 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.

Study Design

Enrollment

15 participants

Anticipated

Intervention Model

Single group

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Participants scheduled to receive 177Lu-PSMA

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.

Interventions

3'-Deoxy-3'-[18F]-fluorothymidine

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 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.

Primary outcome measure

  • Mean Dice similarity coefficient (DSC) [ Time Frame: up to 14 months ]

Central Contacts and Locations

Central contacts

Cancer Connect

800-622-8922clinicaltrials@cancer.wisc.edu

Locations

University of Wisconsin Carbone Cancer Center

Recruiting

Madison, Wisconsin, United States, 53792

More Information

Sponsor

University of Wisconsin, Madison

Last update posted

Oct 23, 2026

Last verified

Oct, 2026

Keywords

  • FLT PET
  • CSE-MRI
  • active bone marrow
  • mCRPC

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-24. This information was provided to ClinicalTrials.gov by University of Wisconsin, Madison on 2026-10-23. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.