Magnetic resonance imaging (MRI) has improved detection of clinically significant prostate cancer (PCa). MRI-guided transurethral ultrasound ablation (MRI-TULSA) system incorporates precise diagnosis and simultaneous ablation of prostate tissue enabling lesion-targeted treatment of PCa. Lesion-based treatment strategy spares surrounding healthy tissues from injury, which may improve the outcome of genitourinary function. This study further investigates the safety and the efficacy of lesion-targeted ablation of MRI-visible biopsy-proven PCa with MRI-TULSA.

Improving diagnostic methods and screening of men with prostate specific antigen (PSA) has led to earlier detection of prostate cancer (PCa) with more favorable disease characteristics. To decrease overtreatment, low risk cases are increasingly treated with active surveillance; nevertheless some of them progress requiring interventions. Intermediate- and high-risk cases need active treatments to improve survival. However, despite desirable local control, the standard therapies including radical prostatectomy and radiation therapy, carry a risk of treatment related adverse effects to genitourinary and bowel functions. There is an eminent need for efficient PCa therapies with minimal effect on genitourinary function and quality of life. To date most studied mini-invasive technologies have used extremities of temperatures to treat PCa including high intensity focused ultrasound and cryoablation.

Magnetic resonance imaging (MRI) has improved PCa diagnosis. Novel MRI techniques enable localization and visualization of clinically significant PCa. Further, MRI can be used for guidance of targeted biopsy from suspicious lesion enhancing detection of clinically significant PCa and pinpointing a target for image guided therapies. Also, increased use of MRI may lead to more MRI-visible tumors encountered in clinical practice developing an unmet need for image guided therapies.

MRI guided transurethral ultrasound ablation (MRI-TULSA) - treatment system offers treatment strategy incorporating precise diagnosis and targeted therapy. It has been evaluated for whole-gland ablation of localized PCa. Further, lesion-targeted MRI-TULSA has been proved to be feasible and safe for treating MRI-visible-biopsy-concordant histologically significant PCa in our phase 1 treat-and-3-week-resect study (not published yet). This current study further investigates the safety and the efficacy of lesion-targeted ablation of MRI-visible biopsy-proven PCa with MRI-TULSA.

Inclusion Criteria:

• Language spoken: Finnish, English or Swedish
• Mental status: Patients must be able to understand the meaning of the study
• Informed consent: The patient must sign the appropriate Ethics Committee (EC) approved informed consent documents in the presence of the designated staff.
• Biopsy-confirmed acinar adenocarcinoma of the prostate
• Gleason score ≥ 3+4/International Society of Urological Pathology grade group ≥ 2
• High volume Gleason score 6 as determined on biopsies (>2 positive cancer core or ≥ 50% cancer in a core)
• Patient presenting low volume Gleason score 6 disease and refuses active surveillance
• Non-metastatic disease; high-risk patients according to European Association of Urology risk group stratification will undergo F-Prostate specific membrane antigen-Positron Emission Tomography/Computer Tomography to exclude distant metastasis
• Lesion visible on MRI (Prostate Imaging Reporting and Data System v2 4-5)
• Eligible for general anesthesia (American Society of Anesthesiologists (ASA)≤ 3)

Exclusion Criteria:

• Contraindications for MRI (cardiac pacemaker, intracranial clips etc.)

  • Acute unresolved urinary tract infection
  • Claustrophobia
  • Hip replacement surgery or other metal in the pelvic area
  • Known allergy to gadolinium
  • Inability to insert urinary catheter
  • Suspected tumor on baseline MRI further than 30 mm or within 3 mm of the prostatic urethra
  • Prostate calcifications or cysts obstructing planned ultrasound beam path within the targeted tissue volume
  • Any other conditions that might compromise patient safety, based on the clinical judgment of the responsible urologist