Feasibility Study on the Use of PET-MRI / 68Ga-PSMA Imaging for HIFU-focal Treatment in the Event of Recurrent Prostate Cancer After Radiotherapy - PSMA Study

Feasibility Study on the Use of PET-MRI / 68Ga-PSMA Imaging for HIFU-focal Treatment in the Event of Recurrent Prostate Cancer After Radiotherapy - PSMA Study

A significant proportion of patients with localized prostate cancer, and treated for curative intent by radiotherapy, have a local recurrence. Among these patients with local recurrence, few receive curative remedial treatment but most of them are treated with palliative hormonal therapy without any chance of long-term recovery.

The use of Focused Ultrasound (HIFU) in focal treatment (only on recurrence) is an effective and not very morbid option, especially compared to surgery. The quality of this treatment is conditioned by both an early diagnosis of recurrence, a precise localization of recurrence in the prostate and a rigorous extension assessment for the detection of occult metastases.

Innovations in medical imaging have led to the development of a new generation of "hybrid" machines that combine PET (Positron Emission Tomodensitometry) and MRI (Magnetic Resonance Imaging) technology. Associated with the use of 68Gallium-labeled PSMA (Prostate-Specific Membrane Antigen), a new tracer specific for prostate cancer, the investigators believe that this PET-MRI imaging technique can:

1. To identify at an early stage the metastatic patients and to allow a more adapted therapeutic management.
2. A better evaluation of the limits of local recurrence and therefore a more precise definition than with MRI alone of the tumor zone to be destroyed.

Finally, the investigators believe that the PET-MRI / 68Ga-PSMA exam, used for the selection of patients eligible for focal HIFU treatment and used for the treatment itself, should allow obtaining an optimal control of the cancer recurrence with the least possible side effects.

Inclusion Criteria:

1. Age ≥ 50 years with a life expectancy of more than 5 years. Patients between the ages of 75 and 80 will need to have a G8 score > 14.

2. Biological recurrence after prostate radiotherapy confirmed with de Phoenix criteria (nadir + 2 ng/mL).

3. No prior or present evidence of lymph node metastasis, soft tissue metastasis or bone metastasis, assessed by the current radiographic exam (PET-Choline) AND the PET-MRI/68Ga-PSMA before Focal-HIFU.

4. Local prostate cancer recurrence confirmed by:

   • A multiparametric MRI showing a single tumor in the prostate gland at most 3 contiguous sextants confirmed by biopsies (Index tumor). Patients with multiple suspected MRI foci may be included if only one of these foci is confirmed by biopsies.
   • Index tumor confirmed by the PET-MRI/68Ga-PSMA.

5. PSA ≤ 10ng/ml.

6. Patient having been clearly informed of the study and having accepted, with sufficient reflection time, to participate by signing the informed consent form of the study.

7. Patient affiliated with health insurance or beneficiary of an equivalent plan.

Exclusion Criteria:

1. Contraindications to Focal-HIFU treatment.
2. Patient with a medical contraindication to Sonovue® injection.
3. Patient with a medical contraindication to MRI.
4. History of uncontrolled cancer and / or treated for less than 5 years (with the exception of basal cell skin cancer).
5. History of sclerosis of the bladder neck or urethral stenosis.
6. Patient at risk of bleeding according to medical advice. Patient with anticoagulants therapy must receive a treatment relay.
7. Patients with unstable neurological pathology.
8. Patient who has been treated for a therapeutic trial within 30 days of enrollment or who wishes to participate in an ongoing study that may interfere with this study.
9. Legal person protected by law.
10. Patient not able to understand the objectives of the study or refusing to comply with postoperative instructions.