[A preliminary clinical study of targeted cryoablation of prostate in the treatment of T3N0M0 prostate cancer].

Objective: To evaluate the clinical efficacy, safety and application value of rectal ultrasound-guided targeted cryoablation of prostate (TCAP) in the treatment of T3N0M0 prostate cancer.

Methods: Transrectal ultrasound (TRUS)-guided TCAPs were performed. And prostate-specific antigen (PSA), TRUS-measured prostate volume, endorectal magnetic resonance imaging (MRI) and spectroscopic imaging (MRSI) at before, 12, 24, 36 months after TCAP were recorded and evaluated. The biochemical relapse free survival (bRFS) and clinical progression (local recurrence and distant metastasis) at 1, 2 and 3 years post-cryoablation were also recorded. The post-TCAP quality of life was also observed by the EORTC questionnaire QLQ-PR25.

Results: The suess rate of this technique was 100%. The follow-up period had a range of 10 to 45 months. The PSA level decreased dramatically (P < 0.01). The TRUS-measured prostate volumes significantly decreased (P < 0.01) versus those at pre-cryoablation. The bRFS at 1, 2 and 3 years post-TCAP was 92.5% (37/40), 87.1% (27/31) and 73.3% (11/15) respectively. The result of quality of life showed that the sexuality scores decreased at 6 months post-TCAP, but there was no statistical significance (P = 0.06) and recovered to baseline level at 12 months. Urinary symptoms improved significantly (P < 0.01). The clinical progression rate in this study at 3 years was 24.4% (11/45). To be specific, local recurrence rate was 54.5% (6/11) and distant metastasis rate 45.5% (5/11). Repeated cryoablation was performed for the patients with local recurrence and satisfactory results were achieved during a follow-up of 10 - 15 months. Endocrine treatment was adopted for the patients with distant metastasis and appeared to have biochemical progression free survival during a follow-up of 6 - 13 months. The therapy was safe. Most of side effects were mild and there was no occurrence of severe complications such as urethral fistulas, etc.

Conclusion: Treating T3N0M0 prostate cancer with TCAP as a monotherapy can obtain a satisfactory outcome during a follow-up of 3 years. But its clinical application value deserves further studies.