Transrectal ultrasound guided cryosurgical ablation of prostate cancer: four-year follow-up study
Purpose: To determine the clinical outcome four years after transrectal ultrasound guided cryosurgical ablation of the prostate for stages T I - T4 cancer.
Method/Materials: Serum PSA and biopsy data were reviewed in 583 patients who received cryosurgical ablation for localized prostate cancer. The median follow-up was 24 months (6-48). 76% of the patients had early cancer (T I - T2), and 24% had locallyadvanced cancer (T3 - T4). Under real time TRUS monitor, multiple cryoprobes were placed transperineally. Either liquid nitrogen or argon gas was circulated as a cryogen. Temperature devices were used to objectify the freezing processes. Two freeze and thaw cycles were used.
Results: Four-year actuarial biopsy proven disease free rate for the entire group was 81%. For stages T1 - T2 and T3 - T4, it was 85% and 66% respectively. The median PSA in the negative biopsy group ranged from 0.1 to 0.3 ng/mI. In the positive biopsygroup, it was 0.8 to 3.6 ng/ml. Major complications of rectal fistula, urinary Incontinence, and urinary outlet obstruction were 0.25%, 4%, and 9% respectively. Impotence occurred in 85% of patients.
Conclusions: Results of actuarial disease free rates at four years after cryosurgical ablation of prostate are encouraging. The complications are also favorable compared to the radical prostatectomy or radiation therapy. This procedure is highly operator dependent. It requires a unique combination of TRUS and interventional radiological skill. Long-term follow-up study is in progress.