古澤 秀実

Hidemi FURUSAWA

ブレストピアなんば病院乳房腫瘍外科

Department of Breast Surgical Oncology, Breastopia Namba Hospital

キーワード : breast cancer, HIFU, therapeutic ultrasound, MRgFUS, spatial resolution

癌は，いわゆる疾患ではなく，自己増殖能力を有する生体内生命体である．乳癌患者の予後を規定しているのは，乳房内に癌が存在することではなく全身転移である．したがって，乳癌局所療法の目的は，「乳房内に生きた癌細胞を残さない」ことである．現時点において乳癌から患者の乳房と生命を守り，患者の身体的侵襲，精神的苦痛を回避しながら乳癌死亡率をも低減させ得る最良の方法は，小さな浸潤癌を発見し治療することである．MR-guided focused ultrasound surgeryは乳房に傷や変形を残すことなく乳房温存手術と同等の治療成績を目指す．当院では，切除臨床試験において乳癌に対するMR-guided focused ultrasound surgeryの効果と安全性を検証し，2005年から放射線照射を併用した非切除臨床試験を進行中である．主な適応基準は，術前薬物療法を行っていず，MRI上限局した最大腫瘍径15 mm以内で，リンパ節転移のない症例とした．これまでに80例を登録して67例の評価症例において，観察期間中央値67ヵ月間で局所再発，遠隔再発，重篤な有害事象を経験していない．整容性は温存手術を凌ぐ．今後，小さな乳癌の発見と非侵襲的治療のために超音波の果たすべき役割はますます大きくなっていくと予想される．

Cancer is not a so-called disease but is another living thing that can propagate itself in human beings. The life expectancy of breast cancer patients depends on the systemic metastasis, not on the existence of cancer in the breast. Accordingly, the aim of local treatment of breast cancer is to completely eradicate the viable cancer cells in the breast. The best approach for the patient is to find and treat the smaller invasive cancer. It can protect the life and the breast of the patient without physical damage and mental suffering. Moreover, it can reduce the mortality rate of breast cancer. The aim of MR-guided focused ultrasound surgery for breast cancer is to achieve treatment results similar to those for conventional breast-conserving surgery. The efficacy and safety of MR-guided focused ultrasound surgery for breast cancer have already been investigated in our excision study. We have been conducting an ongoing non-excision study with radiotherapy since 2005. The major inclusion criteria are no neoadjuvant drug therapy, target tumor less than 15 mm in diameter, well-demarcated mass on MRI, and no lymph node involvement. Sixty-seven evaluated cases of 80 enrolled ones have been followed up for 67 months (median). There has been no local recurrence, no distant recurrence, and no severe adverse events. Cosmetically, this series is superior to conventional breast-conserving surgery. Ultrasound will continue to contribute to detection and treatment of smaller invasive breast cancer.