悪性脳腫瘍に対するstereotactic biopsy―合併症と診断率について

Complications and Diagnostic Yield of Stereotactic Biopsy for the Patients with Malignant Brain Tumors

　Ⅰ．はじめに

悪性脳腫瘍の治療に当たって，組織診断がその治療方針の決定や予後の推定に重要であることは周知のことである^3,4,6)．多くの悪性脳腫瘍において可及的全摘を目指すことが治療において有利であり，また腫瘍のmass effectを減ずる目的から開頭術による生検術が選択されることが多い．しかし，高齢者やperformance statusの不良例，脳の深部腫瘍，多発性病変といった，開頭術により部分ないし全摘出が不可能な症例においては定位脳手術による腫瘍生検術の適応となることも少なくない．stereotactic biopsyを選択するうえでの最大の注目点は合併症率，特に出血率と診断確定率であると考えられる．ことにインフォームドコンセントをするうえで不可欠な情報である．一施設における一定の方法による多数例の報告は，自験例の提示としても他施設との比較においても必要であろう．今回われわれは，臨床診断において悪性脳腫瘍と診断された201例のstereotactic biopsyを経験したので，その成績および合併症について報告する．

　Purpose : The purpose of this study was to assess the complication risk rate and diagnostic yield in a series of 211 procedures performed by a consistent method at one institute.

　Material and method : Two hundred and one patients underwent 211 stereotactic biopsy procedures for diagnosis of malignant brain tumor at Niigata University between 1987-2001. Indication for stereotactic biopsy is decided on the following factors : 1) the patient is elderly or unsuitable for craniotomy ; 2) the tumor location is in a deep,diffusing,multiple,eloquent site ; 3) cytoreductive surgery is not needed to treat the suspected pathology. The specimen was obtained from the target point of CT scan by the aspiration method under local anesthesia except for in six patients who were children or needed operation for a VP shunt under general anesthesia. The lesion was located in 114 cases of cerebral hemisphere,in 44 cases of basal ganglia,in 11 cases of cerebellum and in 11 cases of spreading site.

　Result : Histological diagnosis was obtained in 188 of 211 procedures and the diagnostic yield was 93.5%. There were 104 high grade gliomas,16 low grade gliomas,5 germ cell tumors,37malignant lymphomas,19 metastatic tumors and 13 negative/inconclusive biopsies. Sixteen patients incurred complications (7.6%). Four patients (1.6%) suffered intratumoral hemorrhage. Emergency craniotomy was performed in three patients and stereotactic aspiration of hematoma was carried out in one patient. Furthermore,of 12 complications,9 occurred with the patient showing symptoms of worsening neurological deficit,2 occurred with general convulsion and 1 occurred with severe facial pain.

　Conclusion : This study provided evidence that stereotactic biopsy was a safe and reliable tool for patients with unresectable malignant brain tumors.