Microwave thermoablation for localized prostate cancer after failed radiation therapy: Role of neoadjuvant hormonal therapy

The treatment of residual prostate cancer after irradiation is often associ ated with significant morbidity and a high failure rate. Percutaneous trans perineal interstitial microwave thermoablation is a minimally invasive proc edure used experimentally in our institution to treat selected patients wit h failures of external-beam radiation therapy for prostate cancer. The aim is to ablate all residual intraprostatic cancer thermally. Patients were tr eated under general or epidural anesthesia with transrectal ultrasound guid ance of transperineal placement of the microwave antennas. The rectum, uret hra, and a developed space between the prostate and surrounding tissues wer e actively cooled. The minimal target temperature of the prostate was 65 de grees C for 15 min. The temperature was measured in all cases with intersti tial prostatic thermosensors and in selected cases with online magnetic res onance scanning. Thirty-seven patients with apparently localized prostate c ancer after failure of treatment for cure with external-beam therapy were s ubjected to this treatment, and 20 of these patients have at least 12 month s of follow-up. The initial prostate specific antigen (PSA) concentration r anged from 0.2 to 120 ng/mL. At 12 months, 12 of 20 patients had no biochem ical or histologic evidence of disease, and 11 of 14 patients with initial PSA concentration <10 ng/mL had no evidence of disease. Five of the thirty- seven patients were treated with 3 months of neoadjuvant androgen ablation because the volume of their prostates precluded adequate heating. The avera ge volume decline was 28%, which allowed all men to be treated. Two of thes e patients have been followed for at lease 1 year, and neither shows eviden ce of recurrence. Side effects of treatment in all patients were modest. Pr eliminary results suggest that this treatment might be useful in selected p atients as a salvage therapy after failure of radiation therapy for localiz ed prostate cancer.