Transrectal high-intensity focused ultrasound in the treatment of localized prostate cancer : a multicenter study

Abstract

限局性前立腺癌に対する高密度焦点式超音波療法の多施設共同研究の成績について報告した.対象は, stageT1-2N0M0の72例の限局性前立腺癌で, 症例の年齢中央値は72歳, 血清PSA中央値は8.10n/mlであった.その結果, 治療効果は全体では1年78%, 2年76%が非再発生存であった.浸潤度別に2年目の生化学的非再発生存率を集計したところ, stage T1cが89%, stage T2a 67%, stage T2bは40%(p=0.0817)であった.悪性度別では, Gleason 2～4群は88%, Gleason 5～7群は72%, Gleason 8～10群は80%(p=0.6539)であった.術前の血清PSA値別2年非再発生存率は, PSAが10ng/ml以下群は75%, 10～20ng/ml群は78%(p=0.6152)であった.術後6ヵ月目の前立腺生検では68%において癌細胞は認められなかった.前立腺体積は, 術前24.2mlから術後6ヵ月目14.0mlと縮小していた(p<0.01).IPSS, 最大尿流量率, Functional Assessment of Cancer Therapy(FACT)を用いた生活の質項目は術前後に有意な変化は認められなかった.以上, 高密度焦点式超音波療法は, 術前血清PSA値が20ng/ml以下の限局性前立腺癌に対して低侵襲性でかつ有用な治療法だと思われた

We report a multicenter trial with transrectal high-intensity focused ultrasound (HIFU) in the treatment of localized prostate cancer. A total of 72 consecutive patients with stage T1c-2NOM0 prostate cancer were treated using the Sonablate 500TM HIFU device (Focus Surgery, Indianapolis, USA). Biochemical recurrence was defined according to the criteria recommended by the American Society for Therapeutic Radiology and Oncology Consensus Panel. The median age and prostate specific antigen (PSA) level were 72 years and 8.10 ng/ml, respectively. The median follow-up period for all patients was 14.0 months. Biochemical disease-free survival rates in all patients at 1 and 2 years were 78% and 76%, respectively. Biochemical disease-free survival rates in patients with stage T1c, T2a and T2b groups at 2 years were 89, 67% and 40% (p = 0.0817). Biochemical disease-free survival rates in patients with Gleason scores of 2-4, 5-7 and 8-10 at 2 years were 88, 72% and 80% (p = 0.6539). Biochemical disease-free survival rates in patients with serum PSA of less than 10 ng/ml and 10-20 ng/ml were 75% and 78% (p = 0.6152). No viable tumor cells were noted in 68% of patients by postoperative prostate needle biopsy. Prostatic volume was decreased from 24.2 ml to 14.0 ml at 6 months after HIFU (p < 0.01). No statistically significant differences were noted in International Prostate Symptom Score, maximum urinary flow rate and quality of life analysis with Functional Assessment of Cancer Therapy. HIFU therapy appears to be minimally invasive, efficacious and safe for patients with localized prostate cancer with pretreatment PSA levels less than 20 ng/ml.