LUtetium-177 DOsimetry as a Predictive Biomarker of Response in Metastatic Prostate Cancer Patients Treated With PSMA Radioligand THerapy. (LUDOPATH)

January 19, 2026 updated by: Jules Bordet Institute
A substantial proportion of patients with mCRPC do not respond to 177Lu-PSMA-RLT. The PSA response to Lu-PSMA was observed in nearly 46% of patients included in VISION trial and 66% in LuPSMA trial (4,5). The response to treatment can be evaluated after two cycles using the PSA or PSMA PET/CT scan. Gafita et al. Data have shown that PSA and PSMA perform equally in assessing response to 177Lu-PSMA treatment, and their changes after two cycles are related to patient survival. After two cycles, patients with no PSA or PSMA response had worse outcomes than those with partial response or stable disease . That means PSA and PSMA changes after two cycles can be used as a surrogate of patient outcome. However, the explanation of disease resistance to 177Lu-PSMA-RLT is not yet fully understood. Inappropriate dose administration might be one of the possible explanations. A dose-response relationship has been established in radiotherapy , making dosimetry a standard of care in conventional radiotherapy. In the radionuclide therapy settings, the dose-response relationship has been reported in a multi-center phase 2 trial on the selective internal radiotherapy in hepatocellular carcinoma. In this context, calculating the absorbed dose to tumour lesions could be an excellent method to individualize radionuclide therapy to achieve a maximal response to treatment. If dosimetry calculations could predict which patients would ultimately respond or not respond to treatment, administered dose and number of 177Lu-PSMA-RLT cycles could be adapted early during the treatment course. In this context, our study aims to analyze if absorbed tumour dose obtained by dosimetry calculations could be used as a biomarker to predict non-response to treatment early after one cycle, as the first step towards treatment dose adaptation of a personalized radionuclide treatment approach.

Study Overview

Status

Recruiting

Conditions

Study Type

Observational

Enrollment (Estimated)

110

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

Progressive metastatic prostate cancer

Description

Inclusion Criteria:

  • Male aged ≥18 years with adenocarcinoma of the prostate.
  • Progressive metastatic prostate cancer (progression defined as two consecutive increases of PSA, or progression by bone scan or by RECIST1.1).
  • Candidate for 177Lu-PSMA-RLT, with at least one lesion showing significant PSMA uptake (uptake higher than liver physiologic activity).
  • Able to start treatment within four weeks of baseline PSMA PET/CT.
  • Willing and able to comply with all study requirements

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
eligible patient will perform SPECT/CT and PSMA PET/CT imaging as per local routin

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Patient-based response defined as a decline of serum PSA ≥50% at 12th weeks (after 2 cycles) after treatment initiation.
Time Frame: 12th week after treatment initiation
12th week after treatment initiation

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Jules Bordet Institute

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

February 1, 2026

Primary Completion (Estimated)

December 1, 2027

Study Completion (Estimated)

December 1, 2027

Study Registration Dates

First Submitted

January 19, 2026

First Submitted That Met QC Criteria

January 19, 2026

First Posted (Actual)

January 27, 2026

Study Record Updates

Last Update Posted (Actual)

January 27, 2026

Last Update Submitted That Met QC Criteria

January 19, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IJB-MN-LUDOPATH

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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