High Intensity Focused Ultrasound Hemigland Ablation for Prostate Cancer: Initial Outcomes of a United States Series.

PURPOSE: We report outcomes of hemigland high intensity focused ultrasound ablation as primary treatment for localized prostate cancer in the United States.

MATERIALS AND

METHODS

A total of 100 consecutive men underwent hemigland high intensity focused ultrasound (December 2015 to December 2019). Primary end point was treatment failure, defined as Grade Group 2 or greater on followup prostate biopsy, radical treatment, systemic therapy, metastases or prostate cancer specific mortality. IIEF (International Index of Erectile Function), I-PSS (International Prostate Symptom Score) and 90-day complications were reported.

RESULTS

At study entry patients had very low (8%), low (20%), intermediate favorable (50%), intermediate unfavorable (17%) and high (5%) risk prostate cancer. Median followup was 20 months. The 2-year survival free from treatment failure, Grade Group 2 or greater recurrence, repeat focal high intensity focused ultrasound and radical treatment was 73%, 76%, 90% and 91%, respectively. Bilateral prostate cancer at diagnosis was the sole predictor for Grade Group 2 or greater recurrence (p=0.03). Of men who underwent posttreatment biopsy (58), 10 had in-field and 8 out-of-field Grade Group 2 or greater positive biopsy. Continence (zero pad) was maintained in 100% of patients. Median IIEF-5 and I-PSS scores before vs after hemigland high intensity focused ultrasound were 22 vs 21 (p=0.99) and 9 vs 6 (p=0.005), respectively. Minor and major complications occurred in 13% and 0% of patients. No patient had rectal fistula or died.

CONCLUSIONS

Short-term results of focal high intensity focused ultrasound indicate safety, excellent potency and continence preservation, and adequate short-term prostate cancer control. Radical treatment was avoided in 91% of men at 2 years. Men with bilateral prostate cancer at diagnosis have increased risk for Grade Group 2 or greater recurrence. To our knowledge, this is the initial and largest United States series of focal high intensity focused ultrasound as primary treatment for prostate cancer.