Results of low threshold to biopsy following high-intensity focused ultrasound for localized prostate cancer

ABSTRACT

There are different treatment options for localized prostate cancer. The success of high-intensity focused ultrasound [HIFU] is based largely on biochemical prostate specific antigen [PSA] results. To evaluate the impact of using a low PSA threshold to perform prostate biopsies after HIFU in order to more accurately gauge treatment success. Eleven patients underwent HIFU at Sydney Adventist Hospital in Sydney, 10 as primary and 1 as salvage therapy [post external beam radiation therapy [EBRT]]. The median age was 67 years [49-77 years]. This was a prospective case series. Between 2006 and 2008, the Sonoblate device was used. Prostate biopsies were 12-core biopsies performed under local anesthesia, if PSA was >/= 0.5 ng/mL or after two consecutive rises in PSA. The statistical analysis involved prospective data collection of results to calculate median and ranges. The median PSA at diagnosis was 6.7 ng/mL [5.7-10.8 ng/mL]. The median follow-up was 16 months [7-26 months]. Nine men [82%] had post-HIFU biopsy. The median time to post-HIFU biopsy was 11.6 months [5-20 months], and all nine men had biopsy-proven residual disease. A low threshold to re-biopsy post-HIFU reveals a high local failure rate of 82%. Oncological efficacy is questioned, and using high threshold to biopsy may therefore be overestimating the effectiveness of HIFU as a primary treatment for localized prostate cancer