脳oligometastasesに対する定位放射線治療：case based review

Stereotactic radiotherapy for brain oligometastases：case based review

本特集号のテーマであるoligometastasesの概念は1995年にHellmanとWeichselbaumにより提唱された^1）。限局性の転移性病変に対する根治治療の可能性を示唆し，脳転移もその対象の一つとして記載されている。いまだに確立したOligometastatic disease（OMD）の定義はないが，ESTRO-ASTRO consensusとして既報告をまとめたシステマティックレビューが実施され，現在1～5個の病変を対象にした研究が多く実施されている^2）。OMDを有する患者群は，原疾患や転移病変の部位（骨，肺，リンパ節など）に加え，OMDをきたすまでの経過も多種多様である。そこでESTRO-EORTC consensusにてOMDは9つの病態への分類が提案された（図1）^3）。

The concept of oligometastases was first proposed by Hellman and Weichselbaum in 1995. They suggested the possibility of curing localized metastatic lesions, with brain metastases as one of the targets. Because surgery and stereotactic radiotherapy as metastases directed treatment（MDT）have been established as standard treatments for oligometastatic disease（OMD）of the brain, OMD with brain metastases alone has been excluded in the ESTRO-ASTRO and ESTRO-EORTC consensus. However, the findings of MDT for OMD with brain metastases alone may be useful when considering MDT for OMD in other sites. We report a case based review of long-term survival in an OMD patient with only four brain metastases as metachronous oligorecurrence. The patient received 13-fraction stereotactic radiotherapy, followed by stereotactic radiotherapy for newly found repeat oligoprogression and repeat oligorecurrence. Whether or not brain metastases are included in OMD has not been established, but this case suggests that MDT may provide long-term survival in cases of OMD with four or fewer brain metastases. Many clinical trials for OMD are currently underway, so the impact of brain metastases in OMD should be carefully investigated.