Diagnostic Performance of PSMA PET/CT for Pre-operative Lymph Node Assessment in Intermediate and High-risk Non-metastasic Prostate Cancer (PREOP-PSMA ).

Diagnostic Performance of Prostate Specific Membrane Antigen (PSMA) Positron Emission Tomography/Computed Tomography (PET/CT) Imaging for Pre-operative Lymph Node Assessment in Intermediate and High-risk Non-metastasic Prostate Cancer.

In France, prostate cancer is the most common cancer in men over 50 years of age (nearly 50,000 new cases per year) and is the second most common cause of cancer death in men (approximately 9,000 deaths per year). Although mortality has been declining since the end of the 1990s (about 7%/year), about 30 to 35% of them will have a biological recurrence.

Accurate assessment of local, regional and distant spread of the disease is therefore needed to design optimal personalised care for each patient, either curative or palliative.

Currently, in France, recommended disease assessment includes bone scintigraphy and Abdomino-Pelvic Magnetic Resonance Imaging. However, conventional imaging has limited performance with regard to lymph node extension.

Node dissection is the best way to assess node status. Currently, no imaging exam allows this level of accuracy.

Recently, molecular imaging has emerged as a promising tool to improve the initial extensional assessment of prostate cancer. Prostate-specific membrane antigen (PSMA) is a transmembrane glycoprotein, specific to the prostate, which is over-expressed on the surface of prostate cancer cells.

Recent studies of PSMA PET/CT as part of the initial extension assessment of prostate cancer report superior diagnostic performance in terms of sensitivity and specificity compared to conventional tests, as well as an impact of PSMA PET/CT on patient management.

Inclusion Criteria:

• Histologically confirmed prostate cancer;
• Intermediate-risk prostate cancer (PSA level of 10- 20 ng/mL and/or Clinical tumor stage ≥ T2b and/or ISUP 2 or 3, AND with risk of lymph node extension > 5% according to the Briganti nomogram) or high-risk prostate cancer (PSA ≥ 20 ng/mL and/or TR ≥ T2c and/or ISUP 4 or 5) according to d'Amico classification;
• Curative treatment by radical prostatectomy chosen by the multidisciplinary consultation meeting.

Exclusion Criteria:

• Refusal or inability to participate in the study ;
• Low-risk prostate cancer according to D'Amico's classification, or an intermediate-risk but with a risk of lymph node extension <5% according to Briganti's nomogram;
• Curative treatment other than surgical treatment chosen;
• Life expectancy < 12 months;
• Karnofsky score < 70 or ECOG score > 2.