NCT07609225

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.

Trial Health

63
Monitor

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
15

participants targeted

Target at P25-P50 for early_phase_1

Timeline
37mo left

Started Aug 2026

Typical duration for early_phase_1

Geographic Reach
1 country

1 active site

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

May 20, 2026

Completed
7 days until next milestone

First Posted

Study publicly available on registry

May 27, 2026

Completed
2 months until next milestone

Study Start

First participant enrolled

August 1, 2026

Completed
3 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

August 1, 2029

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

August 1, 2029

Last Updated

July 23, 2026

Status Verified

May 1, 2026

Enrollment Period

3 years

First QC Date

May 20, 2026

Last Update Submit

July 22, 2026

Conditions

Metastatic Castration-resistant Prostate Cancer

Keywords

FLT PETCSE-MRIactive bone marrowmCRPC

Outcome Measures

Primary Outcomes (1)

  • 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

    up to 14 months

Secondary Outcomes (4)

  • Difference in Mean Tumor Absorbed Dose (Gy)

    up to 14 months

  • Variance in Tumor and Bone Marrow Volume

    up to 14 months

  • Variance in Tumor and Bone Marrow Doses

    up to 14 months

  • Difference in Mean Absorbed Dose (Gy)

    up to 14 months

Study Arms (1)

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.

Drug: 3'-Deoxy-3'-[18F]-fluorothymidineDevice: Chemical-shift-encoded MRI

Interventions

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

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.

Also known as: FLT, 18F-FLT
Participants scheduled to receive 177Lu-PSMA
Chemical-shift-encoded MRIDEVICE

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.

Also known as: CSE-MRI
Participants scheduled to receive 177Lu-PSMA

Eligibility Criteria

Age18 Years+
Sexmale
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • 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.

You may not qualify if:

  • 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.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of Wisconsin Carbone Cancer Center

Madison, Wisconsin, 53792, United States

Location

MeSH Terms

Interventions

alovudine

Study Officials

  • Michael Lawless, PhD

    UW School of Medicine and Public Health

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Cancer Connect

CONTACT

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

Study Design

Study Type
interventional
Phase
early phase 1
Allocation
NA
Masking
NONE
Purpose
TREATMENT
Intervention Model
SINGLE GROUP
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

May 20, 2026

First Posted

May 27, 2026

Study Start

August 1, 2026

Primary Completion (Estimated)

August 1, 2029

Study Completion (Estimated)

August 1, 2029

Last Updated

July 23, 2026

Record last verified: 2026-05

Data Sharing

IPD Sharing
Will share
Shared Documents
STUDY PROTOCOL, SAP

Locations

US(1)