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

NCT07370597 | Recruiting

• 1 other identifier: IJB-MN-LUDOPATH
• Study Type: observational
• Target: 110
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Prostate Cancer (Adenocarcinoma)

Outcome Measures

Primary Outcomes (1)

• Patient-based response defined as a decline of serum PSA ≥50% at 12th weeks (after 2 cycles) after treatment initiation.

  12th week after treatment initiation

Study Arms (1)

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

Eligibility Criteria

• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

Progressive metastatic prostate cancer

You may qualify if:

• 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

Sponsors & Collaborators

• Jules Bordet Institute: lead

Study Sites (1)

Institut Jules Bordet

Brussels, 1070, Belgium

RECRUITING

MeSH Terms

Conditions

Prostatic Neoplasms; Adenocarcinoma

Condition Hierarchy (Ancestors)

Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Genital Diseases; Urogenital Diseases; Prostatic Diseases; Male Urogenital Diseases; Carcinoma; Neoplasms, Glandular and Epithelial; Neoplasms by Histologic Type

Central Study Contacts

Carlos Artigas, MD

CONTACT

02.54137.81; carlos.artigas@hubruxelles.be

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 19, 2026
• First Posted: January 27, 2026
• Study Start: February 1, 2026
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2027
• Last Updated: January 27, 2026

Record last verified: 2026-01

Locations

BE (1)