転移性脳腫瘍

METASTATIC TUMORS OF THE BRAIN

I．緒言

　悪性腫瘍の治療に際して，われわれが常に困惑するいくつかの問題の一つとして，脳転移があることは，古くCushingやDandyも指摘しているとおりである。この脳転移の問題が存在するがゆえに，原発巣に対する治療を非常に消極的なものとし，時にはこれを断念せざるを得ないことすらある。しかし近年転移性脳種瘍に対する神経外科的治療の報告を散見するようになり，特に欧米諸国でははなはだ積極的な方向へ進みつつある。ひるがえつて，わが国におけるこの方面の現状をみると未だ十分とはいえず，転移性脳腫瘍に対する認識が高まりつつあるとはいえ，原発性脳腫瘍に対する治療に比較すると，はなはだ不十分な状態と言わざるをえない。

　1952年Stortebecker^9）は早くも150例に上る転移性脳腫瘍の神経外科的観点からの報告を行なっており，爾来いくつかの報告をあげることができる。本邦の報告では，臨床例で桂ら^55）の本邦脳腫瘍症例の統計の中に含まれている若干例と，竹内，矢作^11）12），安藤^1），石川^6）らの報告をみるのみで，悪性腫瘍の脳転移例についての精細な記載を見出し難い。多くは脳腫瘍症例の治療中に偶然見出された転移性脳腫瘍の症例についての報告であつて，わが国におけるこの方面の啓蒙は，欧米に比しなお不十分といわざるをえない。

From 1960 to 1965, 50 cases of metastatic brain tumors have been collected in the Keio University Hospital. During which time 365 cases of brain tu-mors have been operated and verified histologically. The primary origins of the metastasis were, pulmonary cancery 26, breast cancer 6, uterine cancer and cho-rionepithelioma 4, skin (melanoma & melanosarcoma) 2, esophageal and gastric cancers 2, pancreas 1, urin-ary bladder 1, hypernephroma 1, adrenal gland 1, semi-noma 1, rib cancer 1, reticulum cell sarcoma 1, ep-ipharynx tumor 1, and origin unknown 2.

The age distribution was from 16 years to 70 years old, and the location of the intracranial metastasis was, frontal lobe 12, parietal lobe 10, temporal lobe 9, occipital lobe 6, cerebellum 6, brain stem 2 and cranium and dura 5 cases.

The clinical symptoms were analysed and the most prominent symptoms were hemiplegia, mental distur-bances and Jacksonian seizures.

The diagnosis was made mostly by cerebral a-ngiography of bilateral carotid and vertebral arteries.

Upon these 50 cases, major craniotomy was done on 20 cases, decompression operation was done on 6 cases, and on the remaining 24 cases, no neurosurgical treatment was done because of poor clinical condition with multiple metastasis in the central nervous system as well as metastasis to other organs.

The survival period was longest in the cases of ma-jor craniotomy was done, and in those decompression operation and non-operated cases, the survival periods were much shorter than the operated cases.

As the result, it would be concluded that the cases of brain metastasis are pessimistic as for their prog-nosis, because the survival cases were only 6, all of them were operated on with the diagnosis of primary brain tumor before the origins had been identified.

However, if the brain metastasis is solitary and op-erable and the primary origin is resectable, the prog-nosis would be much better by means of surgery as well as radiation and anti-cancer medicine like MMC.

As for the radiation therapy, the linear accellerator seems to be most effective for the primary origin and brain metastasis.