グリオーマのガンマナイフによる治療

Gamma-radiosurgery of intracranial gliomas.

各種頭蓋内グリオーマに対する，ガンマナイフによる治療成績を報告する。Low-grade gliomaのastrocytoma GⅠ，GⅡとoligodendrogliomaは，治療後明らかな腫瘍の縮小と，良好な腫瘍の発育コントロールを示した。最終の経過観察において，GⅠ astrocytomaの83.3％，GⅡの53.3％とoligodendrogliomaの80％に腫瘍の縮小を認めている。少数例ではあるが，腫瘍の完全消失も見られ，かっ経過観察も長期におよんでいることから，ほぼ治癒状態にあると考えられる。一方high-grade gliomaで浸潤性のつよい腫瘍であるanaplastic astrocytomaやglioblastomaの治療成績は，不良でありanaplastic astrocytomaの33％，glioblastomaの10％に縮小がみられたのみであった。これらの腫瘍では，中心壊死の所見は見られるものの，辺縁における腫瘍のコントロールが困難であった。

Follow-up results of various intracranial gliomas treated with radiosurgery are reported. Low-grade gliomas, astrocytoma GⅠ, GⅡ and oligodendroglioma demonstrated remarkable tumor shrinkage and tumor control after the treatment. In fact 83.3% of GⅠ, 53.3% of GⅡ astrocytomas and 80% of oligodendrogliomas demonstrated a shrinkage at the last follow-up. Complete remission was achieved in some cases with GⅠ and GⅡ astrocytomas, which seems to be curative since sufficient follow-up periods were obtained. In contrast malignant and infiltrating tumors like anaplastic astrocytomas and glioblastomas showed a far less favorable responses.One third of anaplastic astrocytomas and 10% of glioblastomas showed tumor shrinkage. Although central tumor necrosis were seen frequently after the treatment, tumor control could not be achieved at the periphery of high-grade gliomas. Rates of tumor control were 100% inGⅠ, 80% in GⅡ, 57% in GⅢ astrocytoma, 25% in glioblastomas and 80% in oligodendrogliomas respectively. These results indicate that only the localized tumors with benign biological behavior are indicated for radiosurgery so far. High-grade gliomas with highly infiltrative and malignant charactors are not good candidate for radiosurgery and have to be treated with combined modalities including this treatment method.