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

Abstract

Context: 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. Aims: To evaluate the impact of using a low PSA threshold to perform prostate biopsies after HIFU in order to more accurately gauge treatment success. Settings and Design: 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. Materials and Methods: 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. Results: 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. Conclusions: 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.

Keywords

• High-intensity focused ultrasound
• prostate biopsy
• prostate cancer