Chronic effect of transrectal split-focus ultrasonic ablation on canine prostatic tissue

Kazuaki Sasaki, Takashi Azuma, Ken Ichi Kawabata, Shin Ichiro Umemura, Ryou Tanaka, Yoshihisa Yamane, Minoru Shimoda

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


The treatment time needed for high-intensity focused ultrasound (HIFU) ablation might be decreased substantially by using the split-focus approach, so we made a prototype 4.2-MHz split-focus therapeutic transducer combined with a small 6.5-MHz imaging ultrasonic probe for transrectally treatment of canine prostatic cancer and used it to experimentally evaluate the feasibility of using splitfocus transrectal HIFU to ablate canine prostatic tissue without injuring surrounding tissues. The prostates of 5 dogs were transrectally treated with split-focus ablation at a peak intensity in the water of 1.7 kW/cm2 for 4 s (4 shots) under the guidance of ultrasonic B-mode imaging. After ultrasonic exposure, the prostates became stiff because of thermal effect of HIFU. For the first 3-5 days after treatment, dogs were catheterized daily for urinary management and treated with oral antibiotics to prevent urinary tract infection. The dogs were able to urinate normally by a week after. Within two weeks a large centrally located cystic cavity had formed in the prostate by replacing the necrotic parenchyma around the prostatic urethra. Necropsy three months after treatment found the rectum and prostate capsule to be normal grossly and histologically. The 4 shots of split-focus HIFU destroyed the prostatic parenchyma and created a prostatic cavity 0.34-0.45 cm3 in volume without injuring surrounding tissues. These results suggest that split-focus HIFU ablation could be used for noninvasive treatment of prostatic cancer in dogs.

Original languageEnglish
Pages (from-to)839-845
Number of pages7
JournalJournal of Veterinary Medical Science
Issue number8
Publication statusPublished - 2006


  • Canine
  • HIFU
  • Prostate
  • Split-focus
  • Transrectal ablation

ASJC Scopus subject areas

  • veterinary(all)


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