COMBINED PSMA-PET/CT AND MRI STAGING IN INTERMEDIATE AND HIGH-RISK PATIENTS PROSTATA-CANCER (COMBINE-P)

Condition(s) studied

Investigational drug(s) / intervention(s)

PSMA-11: PSMA-PET/CT using 68Gallium or 18Fluor or 18DCFPyl as staging prior to Radical Prostatectomy

Study summary

This retrospective, multicentre comparative analysis aims to evaluate a new staging method for i) improved detection of intraprostatic index lesions, ii) local T-staging and iii) lymph node (LN) staging in men with clinically significant prostate cancer (csPCa) at intermediate/high risk by combining prostate-specific membrane antigen (PSMA) positron emission tomography (PET) imaging using different tracers ((18)F) DCFPyL, Gallium-68, Fluor-18) and multiparametric magnetic resonance imaging (MRI) in patients with prostate cancer (PCa) who subsequently underwent radical prostatectomy (RP). Another secondary endpoint will be the additional value of PSMA-PET/CT in men with unremarkable MRI. Men at intermediate risk (PSA \> 10 ng/ml to 20 ng/ml or Gleason score 7 or cT category 2b) or high risk (PSA \> 20 ng/ml or Gleason score ≥ 8 or cT category 2c) who underwent PSMA-PET/CT and mpMRI followed by RP will be analysed in three different subgroups corresponding to the modalities i) PSMA-PET/CT with 18-F-DCFPyL (subgroup/arm A), ii) Gallium-68 PSMA-PET/CT (subgroup/arm B) and Fluorine-18 PSMA-PET/CT (subgroup/arm C).

The validation of the accuracy of the detection of intraprostatic index lesions, local and lymph node staging by MRI and PSMA-PET-CT with different tracers is carried out using the histological radical prostatectomy specimens.

In addition, the prediction of the International Society of Urolgenital Pathology (ISUP) graduation group (GG) within intraprostatic index lesions will be determined using the SUV (standardised uptake value) in PSMA-PET-CT and using ADC values (Apparent Diffusion Coefficient of the diffusion-weighted MRI sequence) in MRI (7,8). The ability of PSMA-PET-CT to predict extraprostatic, i.e. capsule-transcending, tumour growth is also analysed in comparison with MRI. In addition, the correlation of tumour localisation (right vs. left) in relation to positive lymph nodes (right vs. left) is analysed. Finally, the added value of PSMAPET-CT in the case of negative, unsuspicious MRI is determined.

Overall, our analysis aims to improve patient care by analysing the potential of non-invasive "digital biopsy" in terms of lesion detection and prediction of the histological grading group.

In addition, a proof-of-concept for personalised lymph node dissection based on prediction of lymph node metastasis and patient-tailored nerve sparing with accurate prediction of extracapsular extension will be tested based on combined preoperative PSMA-PET and MRI imaging. The results of these two analyses will have a direct impact on clinical practice and the further use of highly specialised imaging.

In addition, this multi-centre data analysis will provide the European Prostate Cancer Center of Excellence (EPCCE) group with a proof-of-concept for future projects.

Eligibility

Primary outcome measure(s)

• The primary outcome includes the correct LN-staging after radical prostatectomy with the use of PSMA-PET-CT with different tracers and mpMRI in patients with significant prostate cancer (ISUP grade group ≥ 2) of intermediate- or high-risk group — 01.01.2026-31.12.2026
  The primary outcome includes the correct LN-staging after radical prostatectomy with the use of PSMA-PET-CT with different tracers and mpMRI in patients with significant prostate cancer (ISUP grade group ≥ 2) of intermediate- or high-risk group

Trial sites (10)