武藤 智

Satoru MUTO

帝京大学医学部泌尿器科学教室

Department of Urology, Teikyo University, School of Medicine

キーワード : prostate cancer, HIFU, minimally invasive treatment

高密度焦点式超音波治療high-intensity focused ultrasound（HIFU）は強力超音波を照射することにより標的となる焦点域内の組織を壊死させ，しかも周囲の正常組織に影響を与えない新しい低侵襲的治療である．限局性前立腺癌に対してもその有用性は立証され，再治療が可能な非観血的治療法として注目されている．また，高齢者や抗凝固療法施行例など合併症のある症例にも安全に行なうことが出来る．最近機器の改良により照射域の温度モニタリングと照射域の追加変更が容易となり，より確実の標的に対する照射が可能となった．他の癌種と同じように，前立腺癌に対しても病巣のみの部分治療であるFocal therapyの必要性が最近認識されつつある．そのデバイスとしてもHIFUの有用性が認められていることから，今後さらに限局性前立腺癌治療の重要な一翼をHIFUが担っていくと考えられる．

High-intensity ultrasound can selectively destroy tissue if delivered in a focused manner without damage to the surrounding tissue. High-intensity focused ultrasound (HIFU) in the treatment of localized prostate cancer can deliver a minimally invasive treatment with effective cancer control. Of particular note, HIFU has the ability to deliver focal therapy of only the malignant lesions within the prostate. One of the advantages of HIFU has been purported to be its repeatability in men who have residual prostate cancer. Patients on anticoagulant therapy, such as warfarin or aspirin, can be kept on their anticoagulant regimens. Recent improvements to the device allow the monitoring of changes in the estimated tissue temperature at the point where HIFU is delivered during HIFU therapy, supporting its authenticity. The idea of treating only the cancer within the prostate and sparing the non-cancerous tissue in the prostate is quite appealing. Some evidence prompted us to use HIFU for focal therapy of a limited area of the prostate in low-risk patients. Consequently, HIFU has been considered to be a forerunner in minimally invasive and focal treatment of localized prostate cancer.