Development of bladder outlet obstruction after a single treatment of prostate cancer with high-intensity focused ultrasound: experience with 226 patients.

PURPOSE

To investigate the occurrence of bladder outlet obstruction (BOO) after high-intensity focused ultrasound (HIFU) therapy of prostate cancer, the need for secondary transurethral interventions for BOO, and the benefit of transurethral resection of the prostate (TURP) before HIFU.

PATIENTS AND METHODS

After a single HIFU treatment between 2002 and 2007, 226 consecutive patients were examined and followed at least 2 years. The Ablatherm Maxis and the Integrated Imaging devices were used. The sites of BOO were recorded.

RESULTS

Median follow-up after HIFU was 52 months (range 24-80 mos). BOO developed in 58 (25.66%) patients. Repeated BOO episodes were observed in 27 (11.94%), three to seven episodes in 13 (5.75%) patients. Patients with repeated BOO were older than patients with singular BOO (71.75 ± 4.97 vs 68.18 ± 5.03; P = 0.024). In primary BOO, multiple sites of obstruction were more often involved than in repeated BOO (25/58 vs 8/27). Conversely, isolated bladder neck stenosis was predominantly found in patients with ≥two episodes of BOO. The rate of primary BOO was significantly different between patients who had undergone TURP the same day as HIFU or within 2 days of HIFU (33/96; 34.38%) and patients with TURP more than 1 month (16/89; 17.98%) before HIFU (P = 0.032). BOO occurred in 21.95% (9/41) of the patients who were treated with HIFU only.

CONCLUSIONS

BOO after HIFU is common, particularly affecting the bladder neck. The risk of repeated BOO is associated with age. A longer interval between TURP and HIFU (>1 month) might reduce the risk for the development of BOO.