Another article about this study helped me understand the results.

“Of those patients in the HIFU arm, 10% eventually underwent salvage treatment, 5% underwent second HIFU, and 2% went on active surveillance. In the RP arm, 13% underwent salvage treatment and 2% went on active surveillance.

Regarding safety, complications greater than IIIa were reported in 2.7% and 2.1% of patients after HIFU and RP, respectively.

As for functional results, urinary incontinence and erectile dysfunction "were significantly lower after HIFU," Rischmann reported.

Specifically, at 12 months, 64% of patients who underwent HIFU had a stress incontinence score of 0 (indicating the patient had no or very mild urinary continence symptoms) compared with 48% of patients in the RP group (risk ratio 0.76, 95% CI 0.70-0.83, P< 0.001).

At 30 months, 62% of patients in the HIFU arm had normal to moderately impaired erections compared to 42% of patients in the RP arm. "So there was significantly less degradation for erectile function after HIFU," Rischmann observed.”
https://www.medpagetoday.com/meetingcoverage/aua/109965