Pilot study of radiofrequency interstitial tumor ablation (RITA) for the treatment of radio-recurrent prostate cancer.

Background: To prospectively evaluate the feasibility, safety, morbidity, and preliminary efficacy of radiofrequency interstitial tumor ablation (RITA) for the focal treatment of patients with local prostate cancer recurrence.

Methods: Eleven patients with biopsy-proven, hormone-naïve, clinically localized prostate cancer were enrolled in a prospective phase I/II trial. Eight patients had failed prior radiation therapy and three were not candidates for curative primary therapy (median Gleason score 7 and 6, respectively). Median follow-up was 20 months. All patients were treated with RITA in an office setting, under intravenous sedation and were discharged after the procedure. Radiofrequency energy was applied via needles placed transperineally under transrectal ultrasound guidance.

Results: The placement of 1/4 lesions was aborted in two patients due to increasing rectal temperature. Complications included transient macrohematuria (19%), bladder spasms (9%), and dysuria (9%). Serum PSA levels decreased after RITA >50% in 90% of patients, > 70% in 72% of patients, and > 80% in 46% of patients. The mean PSA doubling time after RITA was slower than that before RITA (37 +/- 22 months vs. 14 +/- 13 months, P = 0.008). At 12 months after RITA, 50% of patients with sufficient follow-up had no residual cancer on repeat systematic 12-core biopsy cores and 67% were cancer-free in biopsy cores sampled from the RITA-treated areas.

Conclusions: RITA treatment is a minimal invasive, rapid, user-friendly, office-based procedure that is well tolerated. Focal ablation with RITA results in effective local disease control in patients with non-metastatic prostate cancer recurrence. Larger, prospective, multicenter clinical studies are needed to confirm these findings.