Safety and Feasibility of Transperineal Targeted Microwave Ablation for Low- to Intermediate-risk Prostate Cancer.

BACKGROUND: Focal therapy has emerged as an interesting option for localized low- to intermediate-risk prostate cancer (PCa). Targeted microwave ablation (TMA) is a novel FT modality involving targeted delivery of microwave energy under multiparametric magnetic resonance imaging (MRI)/ultrasound guidance.

OBJECTIVE: To describe the step-by-step procedure for TMA and report early functional outcomes.

DESIGN SETTING AND PARTICIPANTS: This was an experimental phase 1-2 trial in 11 patients diagnosed with a single, MRI-visible PCa lesion of up to 12 mm, scored as International Society of Urological Pathology grade group (GG) 1 or 2.

SURGICAL PROCEDURE: Transperineal TMA under MRI/ultrasound image fusion guidance.

MEASUREMENTS: We recorded patient and PCa features; intraoperative and postoperative parameters; pain (Visual Analog Scale [VAS]) and adverse events (Common Terminology Criteria for Adverse Events v5.0); and prostate-specific antigen (PSA), International Prostate Symptom Score (IPSS) and International Index of Erectile Function (IIEF-5) scores at 1 wk and 1, 3, and 6 mo.

RESULTS AND LIMITATIONS: The median patient age was 67 yr (interquartile range [IQR] 18). Median PSA was 5.4 ng/ml (IQR 1.8), median prostate volume was 51 cm3 (IQR 35), and median lesion size on MRI was 10 mm (IQR 4). Ten patients had GG 2 PCa and one had GG 1 disease. The median procedure time was 40 min (IQR 30). No intraoperative complications were reported. All treatments were performed on a day-case basis and no patients were discharged with a urinary catheter. Postoperatively, no grade ≥2 complications were reported. No significant changes in PSA ( p  = 0.46), IPSS ( p  = 0.39), or IIEF-5 scores ( p  = 0.18) scores were reported. The postoperative VAS score at 24 h was 0 for all patients.

CONCLUSIONS: TMA is safe, feasible, and well tolerated in patients with low- to intermediate-risk PCa. Oncological outcomes are still awaited.

PATIENT SUMMARY: Targeted microwave therapy is safe and feasible for selected patients with low- to intermediate-risk prostate cancer. The procedure is well tolerated and does not require a urinary catheter after the procedure. Cancer control outcomes are still awaited.